Suburban Skies

M38 & NGC 1907

2010-04-05T17:34:00.025+01:00

Click on image to enlarge.

Object: Messier 38 (NGC 1912) & NGC 1907

Type: Open Cluster(s)
Distance: 4,200 light years (NGC 1907, 4.500 light years)

Constellation: Auriga

Date: 07 March 2010
Equipment: SXV-H9, Vixen ED 114mm aperture f5.3 refractor, ATIK manual filter wheel, Astronomix LRGB filters
Subframes: 20 x 60 seconds luminance (unbinned), 20 X 40 seconds each for red, green and blue channels (2x2 binned), 16 flats/flat darks in luminance only, calibrated and stacked in AIP4Win, tweaked in AstroArt and PSP7.

A lot of images I've seen of open clusters tend to be a bit overstretched, with faint background stars being amplified to the extent that the cluster is lost against them. It's all a question of personal preference of course, but with open clusters I think it's important to try to aim for something that still resembles a view through an eyepiece.

This image, modest though it is, nicely captures Burnham's "inverted Pi" (or Webb's "oblique cross") of bright stars at the heart of M38. The eye can't really register star colours, but mild processing brought out a pleasing mixture of blue and pink stars across the field. Purists may object to the blue flaring around some of the stars (colour correction on my old Vixen, good as it is, still isn't as good as modern APOs) but I quite like the effect.

Open clusters tend to be overlooked for the splashier or more exotic objects in the sky when it comes to imaging. I like them because they offer easy targets that give very satisfying results without long exposures or too much processing.

This was my first imaging run for quite a while, and with a new EQ6 Pro mount. I've been enjoying views at the eyepiece since I've had the new toy, and whilst I've been getting used to it. I nearly didn't bother, as the line up of M35-M38 from Gemini to Auriga grabbed my eye for a couple of hours or so.

In the end, M38 was the only one in that famous line that I had never imaged - I was also struck visually by how obvious little NGC1907 was (although supposedly a couple of magnitudes fainter than its bigger brother, it makes up for that in compactness). So I blew the dust off of (the outside!) of the SXV-H9, and was pleased to find that both clusters fitted quite nicely on the chip.

I had had a lot of trouble with my old GPDX Skysensor combination of late, and decided back in summer last year to give it a ten-year service. The motor had been stalling in RA (which I attributed to a stiff bearing) and the backlash in RA and Dec was getting unmanageable. The mount came apart easily enough and I cleaned out the tar-like brown gunk from the bearing faces and drive gear that Vixen calls lubricant, and regreased it all with some lithium grease. The worm assemblies I cleaned up with a toothbrush and re-lubricated with some greenish specialist worm gear grease one of the instrument guys at work gave me.

It all went back together just fine and the sticky bearing problem seemed to have been beaten. However, no matter how much I tried adjusting the worm tensioners and bearing end plays, I couldn't reduce the rather large backlash in both axes without the worms becoming too stiff for the motors to turn easily. Added to that, every so often, the RA drive would just fly off randomly at top speed, requiring everything to be turned off to stop it.

This seemed to be attributable to the cheapo nastio plastic connector that plugs the motor cables into the Skysensor handset. I made up an aluminium backplate for the handset, and clamped the cable to it, and this seemed to fix the problem.

But the backlash was defeating my attempts at autoguiding, and I didn't really trust the drives any more - I was worried that the motors would speed off when I was wasn't watching them, smashing the scope into the mount and burning themselves out.

I'd seen both the EQ5 and EQ6 in action, and they seemed to offer good quality and "autoguider friendly" mounts at a reasonable price. I'd also noticed that Orion Optics had quietly dropped the new Vixen mounts (and that stupid Skybook) for their scopes, in favour of the EQ6, which to me spoke volumes.

So I bit the bullet and treated myself to an EQ6. I liked the idea of the extra load capacity offered by the EQ6, as my refractor, guide/spotting scope and imaging equipment all weighs in at around 10 kg total, which is pushing it on the GPDX and probably would for the EQ5 as well.

The EQ6 is a hefty beast, and so I also invested in a trolley with pneumatic tyres to put the whole set-up on. I'd been struggling with the weight of my existing set-up anyway, which was mounted on a hefty wooden box that supported the mount stand and held the electricals. The platform it all used to stand on had also gone rotten, which accounted for my problems in maintaining polar alignment.

I relaid that, and pounded some three foot galvanised scaffold poles into the ground for the screw-down legs of the trolley to stand on.

Set-up is now a breeze and much easier on my aging back, despite the significant increase in weight.

The handset menu and alignment routines aren't as good as the Skysensor (why won't it remember the damn date and time, for example?), but then nothing would be. Vixen were insane to stop making it - it was let down only by its poor electrical connectors.

To date, I've only used the EQ6 for imaging this once, having been quite happy to get used to the mount for visual observation at the moment. The EQ6 is remarkably quiet compared to the old GPDX drives, and the handset direction prompts appears to be completely without backlash, which augers well for when I get around to trying out autoguiding.

GoTo accuracy seems reasonable, although I've found three star alignment to be a bit hit and miss. Provided you stick with the stars the SynScan controller volunteers, things go smoothly. The Skysensor let you keep choosing stars until you could get a three star alignment to stick. As my horizons are restricted, this was quite useful. The EQ6 SynScan just rejects your three star alignment if something isn't quite right, and you have to start again.

For imaging though, my own tests suggests that one star alignment will probably be good enough, provided the reference star is close to the target.

One oddity that I came across was that the drives seemed to freeze if I tried to use a star from the SAO menu as a aid to improving pointing accuracy. Downloading the latest software update from the Synscan web-site seemed to fix that bug, however.

Periodic error of the EQ6 isn't in the same league as the GPDX, as expected. My old mount is around 3 arc seconds, the EQ6 is around 20-25 by my estimates! Autoguiding or (at the very least) PEC is going to be needed for any exposures over a minute, or any focal lengths longer than the 600mm of my refractor.

Still, my first imaging effort was encouraging, and I'll have to see how things progress, work and family commitments permitting!

NLCs over Thames Valley...

2009-07-13T20:35:00.005+01:00

Click on image for larger view

Noctilucent clouds put on a great show last night (July 12th). This was the view from my drive at around 10.30 BST, looking north-west.

I grabbed a series of shots through a Sony Cybershot on auto (camera on a tripod this time) and put two frames together in a mosaic to give the above panorama.

Through 10x50 binoculars, I was surprised at just how dynamic the tiny ripples and pulsations within the cloud filaments were. Movements could be seen quite easily. The display lasted until the early hours of the morning.

NLCs?

2009-06-16T23:30:00.003+01:00

From my bedroom window looking towards the Thames Valley at around 11.15 this evening.

By the time I'd dashed downstairs to get a tripod for my camera, the display of luminous blue streamers had all but dissipated. If these were indeed the noctilucent clouds I've heard rumour of (and they look like it from the photos of others), this is the first time I've seem them for real.

Spooky. Beautiful.

Messier 5...

2009-05-28T23:09:00.015+01:00

Click on image to enlarge.

Object: Messier 5 (NGC 5904)

Type: Globular Cluster
Distance: 24,500 light years

Constellation: Serpens

Date: 26 May 2009
Equipment: SXV-H9, Vixen ED 114mm aperture f5.3 refractor, ATIK manual filter wheel, Astronomix LRGB filters
Subframes: 20 x 60 seconds luminance (2x2 binned), 12 X 40 seconds each for red, green and blue channels, 16 flats/flat darks in luminance only, calibrated and stacked in AIP4Win, tweaked in AstroArt and PSP7.

From the same evening as the previous shot. As I started to image this at about 1.30 in the morning, M5 was already at only about 30° altitude and was starting to sink into the yellow fog of my western horizon.

Not surprisingly, it appeared a lot dimmer on the monitor screen than M3, even though in reality it's around half a magnitude brighter. This is definitely an object I need to revisit earlier in the evening to do it justice!

I was surprised at how blue this came up, even though it was processed in a pretty similar way to my earlier shot of M3. I don't know if that's just an effect of having to stretch the raws that much more to get rid of sky-glow.

With reference to my previous equipment glitch, David "Astroeyes" Moth (of galaxy imaging fame over on the UK SPA gallery site) has also had experience of SS2K crankiness. The connector between the handset and drives is definitely a piece of junk and lets the superb handset down. Both David and I have had the drive act randomly, and I have found I need to be careful not to have the connector under any sort of flexure. SS2K really is a wonderfully easy and powerful GoTo system and it's a shame that Vixen have superseded it with their SkyBook, which I don't care so much for. With SS2K, all the functionality is built in, without having to muck about with downloads, although I will admit things might have improved since I played with an early version.

As for my recent drive problem, I will have a look at the unit encoder - the behaviour does seem like the sort of thing that dust in an encoder might do.

Anyway.

Here's an earlier shot of M5 I took back in 2002:

This was a single afocal frame using a Casio QV-3500Ex and my Vixen VC200L, which actually gives a good impression of what it looks like visually with the same scope under a good dark sky (of the sort I might get once every year if I'm lucky). As with M3, it comes up greenish, although Rob Gendler's work gives a blue colour similar to the one I obtained with the SXV-H9.

Messier 3...

2009-05-27T16:47:00.017+01:00

Click on image to enlarge.

Object: Messier 3 (NGC 5272)

Type: Globular Cluster
Distance: 34,000 light years

Constellation: Canes Venatici

This session did not start particularly well. My venerable Skysensor 2000 GoTo unit has been getting increasingly cranky with age, rather like its owner. This time, when asked to point towards Regulus for initial alignment, the RA drive gave out a strange mewling noise and refused to move. Switching everything off and on again didn't help.

However, when I aimed at Vega as the initial alignment star, everything worked fine. Arcturus and Spica gave me my usual three star alignment in no time. Trying to return to Regulus prompted the drive to sulk again, however.

Regulus is a perfectly respectable star of course, and there was no need for this sort of behaviour. As the time was now around 11 pm though, and with clear and reasonably dark skies overhead, I really didn't want to spend any time fault-finding. Fortunately, when I aimed at M3, the image fell on the CCD chip first time. Tracking wasn't so good, though. The drive seemed a touch jittery and the best I could do was 60 second exposures, even with the PEC running.

Nevertheless this is plenty for a bright globular like M3, provided you don't want to image too deeply. I was interested in a wide field view and was reasonably satisfied with the final result as above, once I processed all of the images and layered them together.

It was certainly an improvement on my first attempt some five years earlier (see below).

I took this afocally with my (now sadly deceased) Casio QV-3500EX digital camera at the eyepiece of my VC200L. It's a single one-minute exposure at ISO400. It's interesting how the colour of this digital camera shot was reflected in the composite from the mono camera above - I have a routine I use for colour compositing in PSP7 and it does seem to match "reality" (subjective though that is when it comes to colours of deep sky objects) quite well.

Rob Gendler shows us what careful processing of top-class images of M3 can achieve here. He also gives us a stack of useful information about this object here.

Once I acquired the frames I wanted for M3, I thought I may as well stay up for another couple of hours and try and catch M5, possibly my favourite globular to look at visually. I don't know how those frames have turned out yet - rigor computoris is setting in and so they'll have to wait.

The Owl Nebula...

2009-03-29T11:47:00.025+01:00

Click on image to enlarge.

Object: Messier 97 (NGC 3587)

Type: Planetary Nebula
Distance: 2600 light years

Constellation: Ursa Major

Date: 25 March 2009
Equipment: SXV-H9, Vixen VC200L 200mm aperture f9 catadioptic, UV/IR filter
Subframes: 17 x 120 seconds (3x3 binned), 16 flats/flat darks, calibrated and stacked in AIP4Win, tweaked in AstroArt and PSP7.

Another clear but very windy night. I had previously used my 200mm Vixen 'scope to visually examine and sketch this object about five years ago. It was a stunningly dark and clear spring night, and the memory of being able to clearly see the "Owl's eyes" has stayed with me ever since then.

Such nights are a rarity in my little light-polluted corner of the world, and this plainly wasn't one of them. Try as I might, I couldn't even see the Owl at all. Indeed, I even had to resort to 3x3 binning to get a image I could see on screen via my CCD.

At a focal length of 1800mm, even my Vixen GPDX won't allow more than a couple of minutes unguided exposures. I have given up on trying to get my SXV-H9 autoguider to work. Despite some very helpful dialogue on the Starlight Xpress board, it's still no go. I thought my wiring was wrong but I've tried the cable with someone else's SS2K and it works. Clearly the fault is with my SS2K handset or the SXV itself - I need to check out my handset with my colleague's set-up...

Anyway, I spent about 30 minutes doing a drift alignment to get the tracking spot on. I usually shoot two minute frames and tweak the mount Alt/Az controls until no trailing is apparent. On this evening, the gusty wind was giving me all sorts of problems with both this and the PEC setting.

In the end, I got something I thought was about right, and went for 50x2 minute exposures at 3x3 binning - the image was so faint I reckoned the extra sensitivity would outweigh loss of detail, especially given the long focal length.

Needless to say, clouds rolled on halfway through the session. I got 37 subs in all, of which only 17 were usable thanks to the gusting wind. So I'm actually quite pleased with the result given the conditions and lack of subs, an image which shows the Owl's eyes reasonably well.

On my image I noticed a smudge of what seems to be nebulosity under the star (GSC catalog number GSC-3824-1065 I think, according to SkpMap Pro 9) just beneath the nebula at the 7 o' clock position. I initially thought that this was a processing artifact, but Johannes Schedler's much better resolved shot shows it as well. SkyMap Pro 9 doesn't show it - there's a galaxy (PGC 34279) indicated nearby, but not quite in the same position

Does anybody know if this star's beard has a designation?

Update: The helpful and knowledgeable folk on the SPA gallery forum have confirmed that my "mystery nebula" is indeed the 16th magnitude galaxy PCG 34279. It prompted me to have a play with using the SLOAN digital sky survey, which is an amazing resource to use. Click on the above link to the forum to see the discussion and links to the SDSS data.

Messier 81 and 82...

2009-03-26T19:30:00.005Z

Click on image to enlarge: North is at 4 o' clock.

Objects: Messier 81 (Bode's Galaxy, NGC 3031, left of frame) and Messier 82 (The Cigar Galaxy, NGC 3034, right)

Type: Galaxies
Distances: 4.5 million light years (M81), 17 million light years (M82)

Constellation: Ursa Major

Date: 23 March 2009
Equipment: SXV-H9, Vixen 114mm aperture f5.3 ED refractor, UV/IR filter
Subframes: 30 x 120 seconds 2x2 binned, no flats or darks, stacked in AIP4Win, tweaked in AstroArt and PSP7.

After nearly a whole month of haze and cloud, at last an opportunity to get some imaging in! I had caught M81 previously and had decided that I would like to get an image of M81 and its attendant "starburst" companion, M82, in the same frame, as the SXV-H9 chip size with my refractor was just about big enough.

This proved a little more tricky to frame than it looked. I'd also got a bit rusty on technique after nearly a month off! It took me a lot longer than usual to get the two galaxies framed, and I was conscious that my last few imaging sessions had been cut short by the appearance of clouds. In the end, I settled for the above, although my SkyMap Pro tells me I could have done a lot better by rotating the camera another 40 degrees or so.

I normally don't bother with dark frames as the SXV-H9 is pretty low on noise given the short exposure I normally use. Flats are, however, essential. However, on this occasion, I inadvertently took the camera off of the telescope when I finished the session. I normally always leave it on, so that I can shoot flats against a white screen in my garage next day.

I'd forgotten that part of my routine because of the weather-enforced layoff. Moving the camera in relation to the telescope obviously invalidates any flat-fielding, so I resorted to gradient and noise filters to hammer out backgrounds that would normally be handled by flats.

The resultant image isn't as detailed as I'd like, but it's not bad. One of these days I'll get a session in where I get everything right...

M81 seems pretty popular on the SPA gallery at the moment, so I haven't posted my effort because there are better ones on there already. I particularly liked Olly Penrice's shot, although he does enjoy dark skies deep in Southern France so he tells us, which is cheating really...

I'm only jealous...

Comet Lulin

2009-02-23T20:49:00.008Z

Click on image to enlarge

Object: C2007 N3 (Lulin)

Type: Comet
Distance: 63 million km at time of imaging
Constellation: Virgo

Date: 21 February 2009
Equipment: SXV-H9, Vixen 114mm aperture f5.3 ED refractor
Subframes: 6 x 60 seconds, 16 flats/flat darks, calibrated and stacked in AIP4Win, tweaked in PSP7.

Look out of kitchen window at 6 pm. Clear, dark, star-studded skies. Don cold weather gear, enter garage, set up equipment and wheel down to observing platform.

Look up in trepidation, given recent weather. Still clear, dark, star-studded skies.

Polar align, set up 3-star align on SkySensor. Not a cloud in sight. Feed in comet orbital parameters to SkySensor and hit GoTo. Comet smack in centre of field. Spend a few minutes looking at it visually and have to admit to being slightly disappointed, having seen images of it and foolishly expecting to see same at eyepiece. I could not really discern a tail, nor any colour in the coma. But a mag 6 comet of any sort is still pretty special and a little spooky.

Remove eye-piece, fit CCD camera. Spend a couple of minutes focusing and another 10 minutes running the periodic error correction to make sure tracking was even. Mistake to faff about with PEC...

Blobs of cloud now starting to blow over. Set up 20 x 60 second exposures on lap-top and hope for best. No chance. Haze already apparent. Six frames later, solid cloud.

Curse luck. Cover equipment with tarp and leave out, hoping skies might clear. They don't. Give up at midnight, switch everything off and wheel back in.

And that was Comet Lulin, that was - for me, anyway. Solid cloud or haze for the next few weeks over my swampy corner of the UK meant I never saw it again. I salvaged what I could and the result is above - the haze gave an impossible gradient and background to the few subs that showed anything, but the core and a trace of coma can be seen.

Some folk had a bit more luck, as can be seen here...

The Cone Nebula...

2009-02-14T19:58:00.002Z

Click on image to enlarge

Object: NGC 2264 (cluster - Cone Nebula is at southern tip of cluster)
Type: Cluster with Nebula
Distance: 2500 light years
Constellation: Monoceros
Date: 24 January 2009
Equipment: SXV-H9, Zeiss 135mm telephoto lens at f3.5, ATIK manual filter wheel, Astronomix H-alpha, green and blue filters
Subframes: 20 x 300 seconds in H-alpha, 10 x 300 seconds in green and blue (unguided, 2x2 binned), 16 flats/flat darks, calibrated and stacked in AIP4Win, colour channels merged in PSP7

I've had several previous attempts at imaging this area, each suffering from poor tracking or poor atmospheric conditions, or both. Once again, my luck was out on this one.

This time, I decided to shoot red (H-alpha), green and blue channels in a 2, 1, 1 rotation, just in case the clouds rolled in and stranded me with half the set of subs needed for a colour image. Sure enough, the miserable run of cloudy skies this winter relented only for a couple of hours before a high haze set in once more.

And once more, my tracking was a tad out, meaning I had to hit the frames with a deconvolution filter to round up the slight trailing on the stars. This leaves dark circles around the brighter stars and also costs some image detail. The Cone Nebula itself stands out quite nicely though, and the extent of nebulosity in the area surrounding the 'Christmas Tree Cluster' can clearly be seen, even if some of the detail is missing.

Still, I'll take what I can get given the weather. Lack of sunspots and cloud nucleation? Global warming meaning more haze at high latitudes?

Or just bloody British weather? It's all very frustrating...

The "69" nebulae...

2009-01-29T18:04:00.032Z

Click on image to enlarge

Object: IC 410 and IC 405 (The "Flaming Star" Nebula, Caldwell 31)

Type: Emission Nebulae

Distance: 1,600 light years

Constellation: Auriga

Date: 23 January 2009

Equipment: SXV-H9, Zeiss 135mm telephoto lens @ f3.5 (40 mm aperture), ATIK filter wheel with Ha, G&B filters

Subframes: 40 x 200s 2x2 binned subframes in H alpha, 12 x 200s 2x2 binned in G, 5 in B, 16 darks, 16 flats/flat darks in Ha, calibrated and stacked in AIP4Win. Final processing in AstroArt, Paint Shop Pro7 and NeatImage.

Despite an ever-increasing haze that cut short my imaging session for this one (hence only 5 blue subs in the end), I was reasonably pleased with the end result. I had planned to take loads more subs if the sky held but given recent history, I was glad I had decided to take a few subs through each filter in turn rather than long sessions through each one.

The channels were stacked in AIP4Win and assigned and aligned in PSP7. The final image was a touch noisy because of the small number of subs, but a quick pass with the freebie version of NeatImage did quite a reasonable job in cleaning it up.

As for the name I gave it, I was just surprised at how sharp the "small 6" of IC410 and "big 9" of IC 405 stood out on the H-alpha frame. The effect isn't quite so striking on the final colour version.

Maybe the final result maybe isn't as good as this one from Greg Parker's New Forest Observatory, but given my somewhat "lower budget" set-up (below), I think I've got value for money on this occasion - especially given the weather...

The shot above (click on the image for a clearer view) shows my current system for wide-field imaging. The equipment is all mounted on a Vixen plate, with the SXV-H9 clamped in a simple bracket made out of a bit of copper tube that I flattened down and drilled. This allows me to rotate the camera for image framing. The filter wheel and lens (with mandatory dew heater) sit on the camera: I've found the filter wheel leaks a bit of light so that's what the silver foil is for. An old Celestron 7 x30 finder is used for rough alignment, with the Vixen guidescope and reticule eyepiece that's above it being used for precise alignments.

It's a simple and robust set-up that stands up quite well to being bounced around on my gadget box when I roll it out of the garage.

Messier 45 - The Pleiades...

2009-01-23T21:11:00.012Z

Click on the above image to enlarge

Object: Messier 45
Type: Open Cluster
Distance: 407 light years
Constellation: Taurus
Date: 18 January 2009
Equipment: SXV-H9, Zeiss 135mm lens, ATIK filter wheel, Astronomix LRGB filters
Subframes: 30 x 300s full resolution subframes (luminance), 20 x 200s RGB 2x2 binned, 16 flats/flat darks (no darks) in luminance, channels calibrated and stacked in AIP4Win. Final processing in AstroArt and PSP7.

It really has been an exceptionally poor winter for imaging so far, has it not? On the few nights that stars are actually visible, there has been a mist lurking around, robbing the sky of any sort of clarity needed for deep-sky work. This particular evening was not really much better but it had been so long that I’d thought I’d give it a go on something bright, like M45, an object I’d never really had much luck in imaging in terms of capturing the delicate nebulosity that suffuses its stars.

Seeing started poor and a high haze became increasingly heavy during this imaging session. I shot what were going to be the luminance frames for the image (200s at full resolution through a UV/IR blocker) first, followed by the red and green frames at 2x2 resolution, and all the while the sky background on the images was getting brighter and brighter. When I finally shot the series of 200s blue frames, I was amazed at how burnt out the stars looked compared to the red and green channels – perhaps an indication of just how “blue” the Pleiades are (or perhaps the lens has a touch of chromatic aberration). I was going to shoot a series of frames at shorter exposures, but by then the stars were virtually hazed out, so I gave up.

The blue frames were a write-off, so I used the luminance channel as the blue one, and pieced together an RGB composite in Paint Shop Pro. This was a bit fiddley as I’d resized the 2x2 binned red and green channels in AIP4Win to match the full resolution luminance channels. In PSP, not only were those images very slightly smaller than the “unresized” ones, there was a bit of rotation as well, probably because I’d had to reverse the equatorial mount between the red and green frames.

The high haze had also caused some horrible gradients across the raw images, and the stacked ones took quite a bit of processing to flatten them out.

It was all a bit much for the AstroArt RGB processing package, which couldn’t stack the colour frames and introduced a load of new coloured gradients anyway, hence a bit of laborious trial and error work to rotate and resize the composites in PSP7 to get something that could be aligned accurately enough to avoid odd and unequal flaring effects on the stars.

With all of this heavy processing, the final image isn’t too brilliant. The brighter stars are still a bit burnt out – you can’t pick out the three small stars just west of Alcyone, for example, which the best shots can clearly resolve. The nebulosity around Merope and is also rather restricted and doesn’t show the “brush-strokes” you see in really good images of this area of the sky.

Whether that’s down to the poor conditions at the time, a poor processing technique and/or insufficient resolution from the 135mm telephoto lens, I’m not sure.

There are certainly better shots of M45 out there than this one. I think I’ll give up on it for now…

The Leo Trio...

2008-12-29T18:18:00.015Z

Objects: NGC 3628 (top), Messier 65 (NGC 3623, lower right), Messier 66 (NGC 3627, lower left)
Type: Galaxies
Distance: 25 million light years (NGC 3628), 24 million light years (M65), 21.5 million light years (M66)
Constellation: Leo
Date: 08 April 2008
Equipment: SXV-H9, Vixen ED114S (f.l. 600mm)
Subframes: 60 x 120 second 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win. Final processing in AstroArt and PSP7.

A very clear, almost moonless night and the AstroArt maximum entropy deconvolution filter both played a part in obtaining crisp, tight star images and a good level of detail in these three galaxies that comprise this well-known grouping.

The refractor's 600mm focal length was ideally suited to the framing of all three galaxies on the SXV-H9 chip without having to resort to a mosaic.

Click on the image to enlarge.

Moon...

2008-12-22T19:04:00.005Z

Date: 24 January 2008

Equipment: SXV-H9, Vixen f5.3 ED refractor (f.l. 600mm)

Subframes: 20 x 0.001 second subframes in OIII, stacked in Registax 2.1. Final processing in PSP7.

Another simple moon shot from a night of terribly unsteady seeing. The OIII filter has generated some excellent contrast of the marias from the highlights and crater debris, especially with the great crater rays of Copernicus and Tycho.

Messier 35

2008-12-20T16:14:00.013Z

Object: Messier 35 (NGC 2168)
Type: Open Cluster
Distance: 2800 light years
Constellation: Gemini
Date: 24 January 2008
Equipment: SXV-H9, ATIK manual filter wheel with Astronomix LRGB filters, Vixen ED114S (f.l. 600mm)
Subframes: 20 x 120 second (luminance), 20 x 60 second 2x2 binned subframes each for R,G and B channels, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win. Final processing in PSP7.

Using my usual "false colour" processing methods for colour renditions of open clusters doesn't work too well. To prepare the above image (click on it to enlarge if you so wish), I used data from monochrome images obtained through colour filters. To try and get realistic colours, I scanned the filters I used into a reference frame, and produced colour masks for each colour channel that were exactly the same colour as that of the filter as scanned in to PaintShop. I then layered each colour channel over the luminance frame, and adjusted the intensity of each layer based on the spectral response for the Sony ICX285AL chip in the SXV-H9.

The result was a load of odd-coloured stars against a dark green sky, so I stopped trying to be clever and just blended the LRGB channels in PSP7 until I got something that looked about right, which is what you see above. The red colour of M35's "neighbouring" cluster, NGC 2158 (a line of sight effect - it lies six times further away) has not been exaggerated compared to the bluish tinge of M35's stars: that's just how they have turned out relative to each other in processing. Looking at other images of this pair of clusters (e.g. such as Rob Gendler's effort here), the colours I obtained seem geniune enough, although "colour" in astrophotos is always a subjective thing. Fans of the "Hubble Pallette" have their very own preference for the psychedelic, after all.

This was the first time I had tried to do "proper" LRGB imaging with a resasonable number of subframes and it's worked out OK. I can see why "one shot" colour CCDs are so popular though, (although I think my skies are too sodiumed-up to allow subjective colour imaging and I prefer the increased sensitivity of the monos as well): gathering the input for separate subs and pasting them all together for a colour composite was quite time consuming.

The of M35 image below is a much earlier one from January 2004:

A single 60 second frame taken by afocal projection through a 25mm eyepiece using a Casio QV-3500EX digital camera gives a reasonable impression of what the cluster looks like under dark skies through an eyepiece, although a hint of star colour is seen in the image. NGC 2158 is barely discernable. Click on the image to enlarge.

Moon...

2008-12-15T18:55:00.006Z

Date: 16 January 2008

Equipment: SXV-H9, Vixen f5.3 ED refractor (f.l. 600mm)

Subframes: 20 x 0.01 second subframes in H alpha, stacked in Registax 2.1. Final processing in PSP7.

After I had finished gathering the subs for my NGC 2175 image, I swung the telescope around to the Moon in Gemini, and shot some subs at full resolution. The SXV-H9 perfectly frames the whole lunar disc at a 600mm focal length. Click on the above image to enlarge - bear in mind it has been compressed to around 140K from the 1.3Mb original.

The hydrogen alpha filter is a good anti-glare device and sharpens up the lunar contrast quite nicely.

The Bubble Nebula...

2008-12-08T18:53:00.010Z

Object: NGC 7635 (Caldwell 11)

Type: Emission Nebula

Distance: 7100 light years

Constellation: Cassiopeia

Date: 6 December 2008

Equipment: SXV-H9, Vixen VC200L (f.l. 1800mm)

Subframes: 22 x 120 second 2x2 binned subframes in H alpha, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win. Final processing in AstroArt and PSP7.

The final image above was salvaged from a catalogue of mini-disasters on a freezing cold and unbelievably soggy Saturday evening.

My first mistake was to attempt to get my SXV-H9 autoguider going. Having found my target and identified a guide star, I spent a frustrating 45 minutes or so trying to get the autoguider to talk to the Skysensor.

First of all, I had forgotten to select the "autoguide" command in the SXV-H9 "default" menu (a step the instruction guide neglects to tell you to do). When I still couldn't get the computer to drive the scope, I tried swapping the cable connection between the "autoguide" socket on the Skysenor and the SXV-H9 (the Skysensor uses a "crossed" signal cable and it's therefore possible - so I thought - to get the cable the wrong way around). To get the guide cable out of the back of the SXV-H9, I had to pull out the signal cable from the autoguider camera to give myself room. When I plugged it back in, I got a white screen on the autoguider image read-out, which I eventually overcame only by rebooting the computer.

I then found that the scope now responded in three directions to guide commands, but not all four, at which point I gave up in disgust. The "crossed" cable was a home build job and I guess I must have missed a wire somewhere.

Meanwhile, clear skies belied the amount of dew that was collecting on every available surface. The VC200L is an open tube scope but I had never had trouble with it dewing up until then. The couple of hours I had spent fannying around with the autoguider had nevertheless allowed dew to completely fog both primary and secondary mirrors.

Ten minutes with a hair-dryer hastily borrowed from the wife's dressing table sorted that out, but by torchlight (an unfair test I know), dried-out clumps of dust were now glued firmly to the previously unsullied surface of the primary mirror, making it look like the surface of the moon.

Having now wasted a couple of hours, I decided to go for 2 minute subframes (I had wanted 5 minute subs, way out of even the GP-DX's capabilities at an 1800mm focal length), which the PEC seemed to allow without significant trailing. I set the camera running to acquire 30 subs, knowing I would probably lose a few to wind or vibration, and that I would have to return to reverse the scope as Cassiopeia would be crossing the zenith, although the GP-DX mount is pretty generous in that respect

When I returned after an hour, the scope was just starting to dew up again. Another blast with the hair-dryer sorted that, and I then spent another 30 minutes reframing the nebula in the field. I decided to put a heating tape around the end of the scope, to try and avoid dewing up. By now, it was bitterly cold, damp and frosty. I set the scope up to gather another 70 subs, and sloped off indoors.

I returned two hours later to find that I hadn't switched the heating tape on, and that I had a scope full of ice and water. Arrrrgh!

Out of 100 frames, only 22 were usable in the end, and I definitely think the dew and dust combination had robbed the stars of their sharpness in those images that were free from trailing or not totally fuzzed by dew later on.

Anyway, the final image, although noisy through lack of subs, shows the full extent of the gas bubble blown from the young blue giant parent, as well as some of the outlying clouds of nebulosity. North is roughly in the 10.00 position.

I now have a scope to clean and a wire to fix. I don't intend to let either beat me, and I WILL get that damned autoguider going...

The "Monkey Head" Nebula...

2008-12-05T18:57:00.003Z

Object: NGC 2175
Type: Emission Nebula
Distance: 7200 light years
Constellation: Orion
Date: 16 January 2008
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 80 x 120 second 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win. Final processing in AstroArt and "photographic unsharp mask" and colours applied in PaintShop Pro7.

I hadn't come across the nickname "Monkey Head" for this particular object until I saw this post by "Paramount" on the Society of Popular Astronomy's Gallery page. I think I can just make out an enigmatic simian grin under the central star of a nose, with the darker areas either side of the star representing two eyes. Maybe.

The tracking was a little off but the deconvolution tool in AstroArt rounded the slightly elliptical stars up quite well - this time, I'd taken enough subs so that the deconvolution process didn't introduce all sorts of artifacts into the image by amplifying high levels of background noise.

I also had a play with Jerry Lodriguss's "unsharp mask" technique (link as above). This boosted the contrast in the image quite nicely, without increasing graininess or putting dark rings around the stars, and it's a technique I'll definitely be looking to use for extended objects like this in future.

I couldn't resist colourising the monochrome result and this worked out quite well on an image compiled from a smaller stack of subs that gave a slightly wider field (the object had drifted quite a way in the field during the course of the evening).

Click on either image to enlarge.

In the literature, there seems to be some confusion over whether the designation of NGC 2175 is referring to the cluster or its nebula. Stephen O'Meara puts us straight in his excellent book, Hidden Treasures: an excerpt that gives lots of interesting information about this oft-overlooked object can be found here.

The Running Man Nebula...

2008-11-30T19:09:00.006Z

Object: NGC 1977
Type: Emission and Reflection Nebula
Distance: 1500 light years
Constellation: Orion
Date: 07 January 2008
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 50 x 60 second 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

Original image above, with a false colour image prepared in PSP7 below. North is up. Click on either to enlarge.

Rob Gendler gives us a breathtaking image of this object, with the adjacent Orion Nebula in the same field.

The Pac-man Nebula...

2008-11-25T13:35:00.000Z

Object: NGC 281
Type: Bright Nebula
Distance: 9400 light years
Constellation: Cassiopeia
Date: 12 November 2007
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 25 x 120 second 2x2 binned subframes in H alpha, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

A moon-free evening and excellent seeing conditions allowed trouble-free imaging of this well-known imaging target in Cassiopeia. The principle features of this nebula are clearly seen, including the striking dark dust lane and dust globule that form the "mouth" and "eye" of the Pacman that lends its name to the nebula's popular moniker.

Below is a false colour version of the above monochrome image, just because I can. Click on either for a larger view.

Johannes Schedler gives us a deeper image of this object and some more information here.

Comet 17P Holmes...

2008-11-20T20:47:00.000Z

I imaged this remarkable exploding comet on October 29th. last year (above, 60 x 15 sec subs - click to enlarge). It was clearly visible to the naked eye in Perseus as a bright fuzzball, about a quarter of the Moon's diameter in binoculars. The "double nucleus" was very apparent and shows up quite well above.

Two weeks later on November 12th. (above, 60 x 45 sec subs - click to enlarge), the comet was still just visible to the naked eye as a faint disc, slightly brighter towards its centre, and whose full extent had now expanded to about three-quarters the size of a full Moon. Both images have been processed in a similar way, but the lower one is the product of longer exposures, which is why it appears to be of comparative brightness

Both images are composites of full frames from the SXV-H9 and 600mm f5.3 refractor.

Lunar occultation of Saturn

2008-11-17T19:54:00.005Z

Date: 22 May 2007, (time 21:18:45 local time)
Equipment: Phillips TouCam, Vixen VC200L (f.l. 1800mm)
Subframes: 300 frames at 20fps, with flats, calibrated and stacked in Registax 2.1.14.0

The above image is a bit of a pastiche as the bright evening twilight, added to the huge difference in brightness and contrast between the Moon and Saturn, rendered Saturn pretty much invisible in my first processing efforts. I shot some more frames of Saturn once the Moon was out of the shot, processed these separately and then "dropped" a layer in Paint Shop Pro containing the processed Moon image over it such that the faint image of the emerging Saturn exactly matched the underlying brighter shot of the planet.

Merging the layers and adjusting the final contrast gave the above "idealised" shot of what the event would have looked like in a dark sky.

I guess the imaging purists might sneer, but I like it.

NGC 7380

2008-11-13T19:36:00.006Z

Object: NGC 7380 (cluster), Sh2-142 (nebula)

Type: Cluster with Bright Nebula

Distance: 10400 light years
Constellation: Cepheus
Date: 11 November 2008
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 50 x 150s 2x2 binned in H alpha, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

I'd love to be able to say that the above image was a product of LRGB imaging, but after acquiring the H alpha frames that I planned to use as the luminance contribution, clouds started making an appearance, so I decided to call it a night (especially as I had to work next day) and "fake it" in PSP7.

The image below is the "real" monochrome one. North is up. Click on either to enlarge.

Rob Gendler, as ever, shows what someone can achieve with skill and dedication (and some rather nifty equipment). As well as a wonderful image, he also gives us some useful information about one of Caroline Herschel's remarkable discoveries and its associated nebula.

I wasn't too sure that the RGB frames would have worked out too well anyway, given the glare of a moon just a couple of days away from full. Moonlight doesn't seem to trouble imaging through an H alpha filter, but I'm pretty sure I would have noticed a loss of contrast on the broader band colour filters.

Incidentally, I use an ATIK manual filter wheel, and find that it "leaks light" rather badly, both around the thumbwheel area and through the casing joint itself. I noticed it when I was shooting some flats, but I can get around the problem by wrapping some foil around the edge of the wheel housing and thumbwheel area. Has anyone else come across the same problem?

And talking of equipment, one of the most useful bits I've bought for ages consists of a pair of battery-powered heated insoles for my shoes (£9.99 from Maplin - 50% off until Xmas). It was pretty chilly on Tuesday night while I was setting up, but these little beauties kept my feet toasty warm.

The cold may no longer be an excuse for not imaging during the forthcoming freezing winter evenings!

Galaxies in Pegasus...

2008-11-10T13:24:00.000Z

A wide field view of the region around NGC 7331, showing Stephan's Quintet (lower right) and numerous other galaxies visible in the same field. Click to enlarge - I've tagged the galaxies I could identify.

The image was taken on 20th October 2007, and comprises of an average of 35 subframes of 120 second duration, taken with the SXV-H9 and the Vixen ED114 refractor.

The Swan Nebula

2008-11-05T19:15:00.000Z

Object: Messier 17, NGC 6618

Type: Bright Nebula

Distance: 4890 light years
Constellation: Sagittarius
Date: 04 August 2007
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 40 x 100s full frame in H alpha, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

This was one of those rare nights when everything went perfectly. The polar alignment appeared to be spot on at the first attempt and the sky stayed crystal clear with a steady atmosphere for the hours around midnight that it took to acquire the frames.

Even though this object never gets much more than about 20º above my southern horizon and the summer sky wasn't truly dark, this effort turned out to be one of my best ever and one of the few that I felt was worthy of a large scale print.

I think it holds up pretty well against deeper images produced by masters such as Johannes Schedler, shown here.

M101

2008-10-31T19:30:00.000Z

Object: Messier 101, NGC 5457
Type: Galaxy
Distance: 17.5 million light years
Constellation: Ursa Major
Date: 17 April 2007
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 60 x 90s 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

My notes record that this wasn't the greatest night for imaging, as a high haze set in whilst I was setting up. Nevertheless, the brighter inner coils of this galaxy (whose full apparent diameter in the sky is nearly that of the full moon) can be seen quite well.

Deeper exposures, such as this one by Johannes Schedler, give the impression of a celestial catherine wheel struggling to hold on to its outer reaches.

The Iris Nebula...

2008-10-28T19:56:00.001Z

Object: NGC 7023, Caldwell 4
Type: Reflection Nebula
Distance: 1400 light years
Constellation: Cepheus
Date: 27 October 2008
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 25 x 100 second 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

Visible through the eyepeice as a mere fuzzy star, this image shows the clover-shaped outer area of dusty obscuring matter that surrounds the bright reflection zone. For some reason, the false colour image below seems to emphasise this slightly better (click on either to enlarge).

Rob Gendler shows us a much deeper and more detailed image here, and also provides a nice chunk of information about this fascinating object.

The Pinwheel Galaxy

2008-10-26T12:59:00.008Z

Object: Messier 33, NGC 598/604
Type: Galaxy
Distance: 2.3 million light years
Constellation: Triangulum
Date: 24 October 2008
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 40 x 120 second 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

From last Friday's moon, cloud and dew-free evening (two within a couple of days - you can bet that'll be it for a while now), I was taken aback by how much of the outlying areas of this old favourite appeared upon image processing, given the relatively short exposures (click on the above to enlarge). I have clearly got the framing of the image about 90º out, as the faint outer edges of the galaxy are just off frame. Rotating the camera would have filled the field a bit better.

I plan to revisit M33 soon using RGB/H alpha filters, for an extended project to try and grab a colour image in a bid to finally produce something along the lines of Richard Best's image here. I particularly like this one as other images I have seen of this object have either burnt-out cores, or have garishly exaggerated the numerous H-alpha regions that are within M33's spiral arms.

NGC 2403

2008-10-24T13:24:00.009+01:00

Object: NGC 2403 (Caldwell 7)

Type: Galaxy

Distance: 14 million light years
Constellation: Camelopardalis
Date: 13 March 2007
Equipment: SXV-H9, Vixen ED114 refractor (f.l. 600mm)
Subframes: 25 x 150s 2x2 binned subframes, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

This faint fuzzy, barely distinguishable through a 25mm eyepiece on the above refractor from my light-polluted location, reveals itself to be a miniature of the great spiral in Triangulum (Messier 33) when imaged with the magic of CCD.

My notes at the time didn't give a reason for only shooting 25 subs as, coming back to the image, it looks like everything else, such as tracking, quality of flats etc, was pretty much OK. The image therefore suffers from noise which a larger number of sub-frames could have helped beat down.

The loose-limbed nature of this galaxy is clearly distinguishable, however (click on the above image to enlarge). Rob Gendler gives us a much more detailed view of this object here.

NGC 7331

2008-10-22T20:51:00.017+01:00

Object: NGC 7331

Type: Galaxy

Distance: 50 million light years
Constellation: Pegasus
Date: 21 October 2008
Equipment: SXV-H9, Vixen VC200L (f9, f.l. 1800mm)
Subframes: 30 x 60s 2x2 binned subframes, stacked in AIP4Win.

A crystal clear, moon free evening allowed me to attempt imaging this fuzzy in Pegasus. A slim lens shaped glow with a bright central star-like centre was clearly visible through a 25mm eyepiece on the VC200L.

Swopping the eyepiece for the SXV-H9, I thought I'd have a quick play at checking the scope's collimation using the free trial download of CCDWare's CCD Inspector. It's dead easy to use and I was pleasantly surprised to find that the VC200L appeared to be spot-on. Not sure I'm advanced enough yet to want to fork out for a "keeper", though...

Getting a polar alignment that was accurate enough to avoid tracking errors at an 18oomm focal length was a bit more of a challenge. The GPDX mount's polar alignment scope usually puts me pretty close, but that isn't good enough for imaging with the VMC, and I have to resort to repeatedly downloading 30 second frames and iteratively adjusting the mount alignment until no trailing is evident and the stars stay in exactly the same position for a few minutes. It took me about 40 minutes to get an alignment I was happy with.

Running the periodic error correction then seemed to remove the last few jitters from the otherwise pretty smooth drive. I had planned to take at least a hundred 60 second subs, and then try my luck with some longer ones afterwards. I watched the first few download and then left the equipment to do its stuff.

Mistake. I had clumsily let the lead to the RA drive trail over the counterweight shaft, and as the mount tracked, it pulled the lead tight and then out of the motor! I returned after a couple hours to find I had only got about 30 subs of the 100 I wanted, and as it was now past midnight and I had to work the next day, I gave imaging up as a bad job. A stack of what I got is what you see, a lot noisier than I would have liked, but still showing a moderate amount of detail (click to enlarge).

Ace astroimager Rob Gendler brings out slightly more detail in his effort here, showing structure in the associated "Deer Lick" group of galaxies (also nicknamed "the Fleas", so I gather) that show up as mere fuzzy blobs on my more humble effort.

Frustrations aside, the night really was too clear to miss out on though, so I dropped the 25mm eyepiece back in and spent 30 minutes or so getting some knock-out views of open clusters M52, NGC 884 & 869 (the Double Cluster, each of which fitted nicely into the field of view) and NGC 457 (the Phi Cas cluster, which I had never seen before and which almost appeared three dimensional it was so bright) before finally calling it a night.

It's not all about gadgets...

Work and sleep - the twin curses of amateur astronomers everywhere.

The Jellyfish Nebula...

2008-10-15T18:48:00.009+01:00

Object: IC 443

Type: Supernova remnant

Distance: 5000 light years
Constellation: Gemini
Date: 09 March 2007
Equipment: SXV-H9, 400mm Vixen guidescope
Subframes: 33 x 300s 2x2 binned subframes in H alpha (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

A dark, clear evening allowed me to have a crack at imaging this supernova remnant in Gemini. To frame the object on my SXV-H9, I used a 400mm focal length Vixen guide scope which is of surprisingly reasonable optical quality.

The result above was OK-ish (click on the image to enlarge), but I'm starting to think I need to sort out some sort of permanent polar alignment, master autoguiding and get a good quality lens in the 300-400mm focal length range as the stars still show a trace of trailing.

I could then go for longer subs at full resolution without star trailing or other aberrations, which limits my current efforts.

Master astrophotographer Johannes Schedler of Panther Observatory fame provides a gloriously detailed wide-field image of this object here.

The Egg and Spoon Nebula...

2008-10-12T14:25:00.010+01:00

Object: NGC 7822 & Cederblad 214 (Sharpless 2-171)

Type: Bright Nebula

Distance: 2750 light years
Constellation: Cepheus
Date: 11 October 2008
Equipment: SXV-H9, 135mm telephoto lens
Subframes: 40 x 300s 2x2 binned subframes in H alpha (unguided), 30 darks, 30 flats/flat darks, calibrated and stacked in AIP4Win.

Ace astroimager Rob Gendler tells us in his wonderful book "A Year In The Life Of The Universe", that "the faint northern arch of nebulosity is designated NGC 7822, and the brighter southern cloud is designated S 171, from naval astronomer Stewart Sharpless' 1959 catalogue of HII regions." The SkyMap Pro software I use to plan imaging sessions indicates that the lower cloud is denoted as Cederblad 214, the whole area of nebulosity being designated Sh2-171.

Whatever the "proper" designations, the brighter parts of this complex always (photographically at least) remind me of an egg (the C-214 portion) and spoon (NGC 7822), so I've decided to call it that.

A gibbous moon just a couple of days off full coupled with an ever-increasing soggy mist didn't aid particularly detailed imaging, but the main bright and dark features of the area are nevertheless visible in the above image (click for a larger view, for what it's worth). Mr. Gendler's expert rendition can be seen here. Something to aspire to, I guess...

A false colour image is appended below.

IC 434

2008-10-11T11:13:00.006+01:00

Object: IC 434

Type: Bright Nebula

Distance: 1300 light years
Constellation: Orion
Date: 02 February 2007
Equipment: SXV-H9, 300mm telephoto lens
Subframes: 42 x 120s 2x2 binned subframes in H alpha (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

The telephoto lens used was another junk store purchase and close examination of the star images shows some distortions. This was the same lens used to produce the image of the Rosette Nebula I posted earlier. Image processing can clean up the worst defects and the lens (of unknown make - probably Russian as the name appears in Cyrillic) is perfectly acceptable for use on extended nebulousity.

Below is a false colour image, compiled using data from above, from an earlier shot of the "Flame Nebula" portion (NGC 2024) and also from a shot I took of the Horsehead region to provide more detail of the adjacent small patch of nebulosity NGC 2023.

Click on either for a larger view.

The California Nebula

2008-10-03T17:25:00.008+01:00

Object: NGC 1499

Type: Bright Nebula

Distance: 7300 light years
Constellation: Perseus
Date: 16 December 2006
Equipment: SXV-H9, Zeiss 135mm telephoto lens
Subframes: 16 x 180s 2x2 binned subframes in H alpha (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

False colour image below (from a crop of the above). Click on either for a bigger view.

Never sure about the popular name. I think it looks like a squid...

The Double Cluster

2008-10-01T17:40:00.013+01:00

Object: NGC 884 & 869 (Caldwell 14)
Type: Open clusters
Distance: 7300 light years
Constellation: Perseus
Date: 16 December 2006
Equipment: SXV-H9, 400mm focal length Vixen guidescope
Subframes: 20 x 60s subframes in RGB, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

Note: Must refocus between red, green and blue filter changes as 400mm spotting scope is not well-corrected. Hence the bloated redder stars.

The Pleiades

2008-09-25T18:14:00.008+01:00

Object: Messier 45
Type: Open cluster
Distance: 407 light years
Constellation: Taurus
Date: 09 December 2006
Equipment: SXV-H9, Soligor 200mm telephoto lens
Subframes: 20 x 180s subframes at full resolution, 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

The stars are rather bloated and I think it may be down to the lens really not being too good in terms of chromatic aberration (see Great Andromeda Nebula). And whilst some of the famed nebulosity is visible, there isn't as much of it as the experts can show us.

Longer subs and colour filters may bring out more detail and sharpen up the stars, and I will give it a try before I give up on this lens.

An afocal view (single one minute exposure) with my old Casio digital camera, afocally coupled to a 25mm eyepice on my Vixen ED 114mm aperture/f5.3 refractor, gave this result in 2004.

No nebulosity, but nice stars.

Gamma Cygni nebulae

2008-09-21T21:38:00.006+01:00

Object(s): IC 1318, 1318A (bright nebulae), NGC 6910 (cluster)
Type: Nebulae and open cluster
Distance: 5000 light years
Constellation: Cygnus
Date: 14 August and 18 September 2008
Equipment: SXV-H9, Zeiss 135mm telephoto lens
Subframes: 2 frame mosaic prepared from two lots of 30 x 300s 2x2 subframes in H alpha(unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win, mosaic in AstroArt.

At last, a spell of clear weather in this miserable year has allowed me to finish off a project I started a month ago. The area spanning nearly 4° across, centred around Sadr (gamma Cygni), consists of a complex mass of bright and dark nebulosity that can pretty much only be detected by photography (at least, from my neck of the woods).

IC 1318 forms one wing of the "Butterfly Nebula" and is the bright patch in the lower left hand corner of the above image (click on the image to enlarge -about 200K). IC 1318A is the wedge-shaped nebula in the top right hand corner. North is up and east is to the left, just how you'd see it in the sky.

The tiny cluster just above Sadr is NGC 6910, which is very much further away than the nebulae itself. Sadr is a foreground star "only" 1500 light years away, the nebulae being powered by a more distant star buried in the dark clouds of obscuring matter.

Both sessions were hampered by a bright moon, but the magic of a Hα narrow band filter eliminated any gradients or poor contrast arising from moonlight.

Needless to say, the resolution in this image can't compare with equivalents taken with big chip CCDs and wide-field Apos set on equally expensive mounts, but I'm pretty pleased with the result of my more modest set-up.

Above is a false colour image of the monochrome original, just because I can, really (click on it to enlarge if you so desire). My technique has rather clipped the fainter traces of luminosity and I think I prefer the monochrome one...

The Great Andromeda Nebula

2008-09-16T19:15:00.006+01:00

Object: Messier 31 (NGC 224)
Type: Galaxy
Distance: 2.3 million light years
Constellation: Andromeda
Date: 09 December 2006
Equipment: SXV-H9, Soligor 200mm telephoto lens
Subframes: 50 x 90 second full frame (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

I was quite pleased with this although the brighter stars are a little bloated and have halos - I don't think the lens is a particularly good one with respect to chromatic aberration. It may be OK on narrowband or with colour filters. I'll get around to trying this one again using a filter wheel.

The Helix Nebula

2008-09-15T18:25:00.006+01:00

Object: NGC 7293 (Caldwell 63)
Type: Planetary Nebula
Distance: 522 light years
Constellation: Aquarius
Date: 28 September 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor
Subframes: 16 x 180 second full frame (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

This really was a game of "how low could I go?" The Helix Nebula never gets more than 17 degrees above my cluttered horizon, and even then only between a gap in two close-by houses (hence only 16 subs). Add to that a horrendous light pollution gradient, and it makes for some challenging processing problems.

Nevertheless, it's possible to determine some structure in the final somewhat noisy image, and it showed to me that getting a half-decent low elevation shot was possible even under my limited viewing conditions. Had the weather been kinder this year I would have aimed for the Trifid Nebula (M20) and Lagoon Nebula (M8) which lurk in Sagittarius at 15 and 14 degrees respectively. The H-alpha filter (not used here) will certainly help with M8, I think.

Comet C/2006 M4 (Swan)

2008-09-09T19:28:00.004+01:00

Object: Comet C/2006 M4 (SWAN)
Constellation: Corona Borealis
Date: 24 October 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor
Subframes: 20 x 120 second full frame (unguided, tracked on comet nucleus), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

This object unexpectedly brightened to around 4th magnitude and was easily visible to the naked eye, even from my light polluted corner of the world. Having learned from earlier efforts, I went for longer subs to catch detail in the tail, and also tracked using the comet orbital parameters (entered into the GPDX SkySensor hand controller) rather than simple sideral tracking. The tracking was virtually perfect, more by luck than judgement, enabling me to get my best shot of a comet to date.

Once again, I wished I'd taken more subs as the image is still a bit noisy, but as this one was on a hyperbolic orbit, it won't be coming back to let me have a second go...

The Cygnus Loop

2008-08-31T20:42:00.005+01:00

Object: Veil Nebula and Witch's Broom Nebula (NGC 6992-6995 & NGC 6960, Caldwell 33 & 34)
Type: Supernova remnant
Distance: 2500 light years
Constellation: Cygnus
Date: 03 September 2006
Equipment: SXV-H9, Astronomix H-alpha filter, 135mm Zeiss telephoto lens
Subframes: 2x2 binned, 22 x 180 second (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

Whilst the resolution in this image can't match that offered by wide-field Apos and big-chip CCDs, I think I've got value for money out of my rather more modest set-up. The filamentary structure of both the eastern Veil portion and the western "Witch's Broom" can be seen, along with the fainter central wisps of nebulousity between the two (click on image to enlarge).

Not bad for a lens picked up for a few quid at a boot sale. Longer subs would probably have shown more detail in the fainter wispy stuff.

The Eagle Nebula

2008-08-20T19:57:00.000+01:00

Object: Messier 16 (NGC 6611)
Type: Open cluster with nebula
Distance: 9000 light years
Constellation: Serpens Cauda
Date: 15 July 2006
Equipment: SXV-H9, Astronomix H-alpha filter, Vixen 114mm f5.3 ED refractor
Subframes: 16 x 120 second (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

I was restricted to only 16 subframes as the low altitude of this object means I can only catch it for about an hour as it passes between a gap in two houses that block out my view of the lowest regions of my southern sky.

The amount of detail in the final image was therefore quite pleasing.

M81

2008-08-18T19:33:00.004+01:00

Object: Messier 81 (NGC 3031)
Type: Galaxy
Distance: 4.5 million light years
Constellation: Ursa Major
Date: 01 April 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor
Subframes: 50 x 80 second (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win.

This came out OK, despite some star trailing due to poor polar alignment. The low noise in the final image allowed me to get away with using a deconvolution filter in AstroArt 4 to round up the star images and sharpen the whole thing up to an acceptable standard.

I had planned to take a second series of images just north of the field shown here to catch M82 as well, the plan being to mosaic the two outputs together. Needless to say, the clouds rolled in just as I was framing M82.

One for another evening, then. According to my calculations, the field of view available with the 600mm focal length refractor/SXV-H9 combination should just be able to fit M81 and M82 on the same frame, so I'll be trying that next spring.

The Christmas Tree Cluster

2008-08-16T17:13:00.006+01:00

Object: NGC 2264
Type: Cluster with Nebula
Distance: 2500 light years
Constellation: Monoceros
Date: 03 March 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor
Subframes: 20 x 180 second (unguided), 16 darks, 16 flats/flat darks, calibrated and stacked in AIP4Win. Colours added in PSPv7

Maurice Leyland's "Christmas Tree Cluster" (NGC 2264) can readily be made out here. The "tree" is upside down even though it's the right way up, if you see what I mean - an eyepiece normally inverts the view giving the cluster its striking resemblance to the proverbial Christmas tree

I used the magic wand tool and some masking layers in Paint Shop Pro to add the red colour to the faint nebulousity that enmeshes the cluster, and to give a blue halo to the brighter stars. The false colours actually help to highlight the nebula for some reason, which is why I've posted this image rather than the usual monochrome output from the SXV-H9. Click to enlarge.

The Cone Nebula can be made out at the southern end of the nebulousity. The whole of the nebula associated with NGC 2264 is just the brighter part of a vast cloud of nebulousity in this region of sky. I had a semi-successful attempt at imaging this cloud in hydrogen-alpha, using the SXV-H9 and a 135mm telephoto lens, giving a theoretical field of 2.8 x 3.8 degrees (see below).

Unfortunately, the tracking seems to have been a bit off for the duration of the 300 second subs used, hence the rather bloated-looking stars. I can and will do better on this one.

Partial Solar Eclipse

2008-08-15T18:28:00.001+01:00

From 3rd October 2005. I used the Vixen 114mm f5.3 ED refractor fitted with Baader solar film and a Casio digital camera afocally coupled to a 15mm eyepiece. The exposures were 1/400th of a second. As these eclipses are fairly leisurely affairs, I simply took single frames every five minutes

It's said that all but the least partial of partial eclipses aren't really noticeable if you aren't actually looking at the Sun. At around 10.00 for this one however, I felt that the autumn sunlight had a washed-out quality and that it was distinctly cooler for a while. Maybe it was just psychological...

The Flame Nebula

2008-08-13T21:41:00.001+01:00

Object: NGC 2024

Type: Nebula

Distance: 1300 light years

Constellation: Orion

Date: 28 January 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 15 x 180 second, unguided, no darks or flats.

Apparently this object is part of the same molecular cloud that encompasses the M78 complex (see previous post), which is some 2 degrees to the northeast. I recently reprocessed these subs in AstroArt 4 and I think they have scrubbed up quite well, even without the benefit of a flat frame.

This object has been saddled with several names, some of them quite inappropriate for its delicate beauty. Some US (who else?) astromoners have called this the "Burning Bush Nebula" (clumsy, but at least understandable), the "Lips Nebula" (ugh!) or even the "Tank Track Nebula" (good grief...).

"Flame Nebula" is just fine for me...

M78

2008-08-12T20:22:00.001+01:00

Object: Messier 78 (NGC 2068)
Type: Nebula
Distance: 1630 light years
Constellation: Orion
Date: 28 January 2006
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor
Subframes: 17 x 180 second, unguided, no darks or flats.

Same old mantras (mantrae?) of "more and longer subs" and "could do with a flat field". At the time I took this image though, I didn't have any image stacking software, other than the clunky package that came with the SXV-H9 camera itself, so I tended to shy away from flat fields.

This curious mixture of dark and reflection nebulae still shows up reasonably well though. It's another one I plan to revisit now I have more experience, better software and a colour filter wheel.

M78 is the nebulousity in the bottom half of the frame - the upper one is NGC 2071. The smudges just to the northwest and southwest of M78 also have their own NGC designations, NGC 2067 and 2064 respectively.

Mercury and Venus conjunction...

2008-08-11T20:19:00.003+01:00

This one caught me by surprise on the evening of 27 June 2005. By chance I happened to look at the western horizon and noticed that Venus had a dimmer companion very close by. A quick look at SkyMapPro showed that Mercury was only about 5 arc-seconds from Venus and wouldn't appear any closer than that until December 1st 2070, (and that during the day from the UK too).

Figuring that I was very unlikely to get this weird photo-oppportunity again, I grabbed the VC200L, the Toucam and my lap-top and set up to grab a few frames. The image above is a Registax of 30 seconds-worth of 15 frames/second images taken at around 21.00 BST. The blue sky is not an artifact. The phases of Venus (91%) and Mercury (61%) show up reasonably clearly.

In hindsight, I wish I'd used the wider field refractor to give an impression of just how close the pair looked. Oh well, I'll guess I'll try and aim to stick around for 2070..

Comet C2001-Q4 NEAT, Venus

2008-08-10T19:43:00.002+01:00

Object: C2001-Q4NEAT

Type: Comet

Constellation: Cancer

Date: 19 May 2004
Equipment: Casio digital camera, 25mm eyepiece afocal, Vixen 114mm f5.3 ED refractor

Subframes: 8 x 60 second, unguided, no darks or flats.

This little blue fuzzball was an early evening binocular object low in the western sky for a few days in the summer of '04. The above image is horribly vignetted and a bit noisy but nonetheless doesn't do too bad a job at portraying the comet's telescopic appearance. More talented imagers than I produced some wonderful images showing all sorts of long tails, but I'm just "glad I was there"...

A 12% phase Venus was also brilliantly on show lower on the horizon, so I rattled off forty or so 0.1 second frames and Registaxed them. I quite like the enigmatic feel of the result...

M52 and NGC 7635

2008-08-05T19:13:00.004+01:00

Objects: Messier 52 (NGC 7654) and NGC 7635 (Caldwell 11)

Type: Open Cluster and Nebula

Distance: 5100 light years (cluster); 7100 light years (nebula)

Constellation: Cassiopeia

Date: 31 December 2005
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 20 x 180 second, unguided, no darks or flats.

A night of poor seeing rendered the cluster stars not as sharp as they could be in the above image, but the ghostly form of NGC 7635 and its component "Bubble Nebula" can still be readily discerned. I plan to return to the Bubble with the VC200L and a Ha filter sometime.

In terms of the M52 cluster, I think the digital camera effort below (afocal, 25mm eyepiece with the VC200L, eight 60 second frames combined in AIP4Win) from October 2004 actually shows it as it appears through the eyepiece and does the object some justice. Click on either to enlarge.

Mars

2008-08-04T19:43:00.005+01:00

Date: 17 November 2005
Equipment: Phillips TouCam and x2 Barlow on the VC200L (f18 in total)
Subframes: 500 x 1/10 second, processed in Registax.

Mars was around 19" in diameter and was just past the October 30th opposition. It won't get as big again until just before the opposition of 2018, which will be low down in Capricorn and pretty much hopeless for UK observers.

I might have got the hang of web-camming by then...

Sun-spots

2008-08-02T19:10:00.001+01:00

Date: 25 October 2003
Equipment: Casio QV-3500EX digital camera coupled afocally to a 25mm eyepiece on a Vixen 114mm f5.3 ED refractor fitted with Baader solar film
Subframes: 10 x 1/400 second.

Our nearest star is currently going through a solar minimum in terms of sun-spot activity, with a disc that is often blank for weeks on end. However, even during the maximum of the previous sunpsot cycle five years ago, having two big active regions such as AR486 and AR484 on the disc at the same time was regarded as rather unusual.

I picked through about forty images and stacked the clearest ten in Registax. A mild sharpening and subsequent yellow colour mask (Baader film gives a white disk) gave the above result.

IC342

2008-07-30T21:16:00.000+01:00

Object: IC342 (Caldwell 5)

Type: Galaxy

Distance: 13 million light years

Constellation: Camelopardalis

Date: 31 December 2005
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 8 x 300 second, unguided, no darks or flats.

A mediocre effort that shows the limitations of unguided exposures. This dreadfully dim galaxy needs more and longer subs to do it justice, I think, but even the GPDX won't track that well unguided for the lengths of subs probably needed.

Nevertheless, the spiral structure just about shows up through the noise.

Jupiter

2008-07-21T21:00:00.003+01:00

Object: Jupiter

Date: 29 December 2001 (21.31 GMT)
Equipment: Casio digital camera, 9mm eyepiece afocal, Vixen VC200L

Subframes: 10 x 0.2 second, no darks or flats.

I've never had a lot of success imaging planets and this effort has been my most successful to date. Registax allowed me to pull out Europa and a transit of Io as well as the GRS.

The Cocoon Nebula

2008-07-20T20:53:00.005+01:00

Object: IC5146 (Caldwell 19)

Type: Nebula

Distance: 3300 light years

Constellation: Cygnus

Date: 28 August 2005
Equipment: SXV-H9, Vixen 114mm f5.3 ED refractor

Subframes: 24 x 120 second, unguided, no darks or flats.

This object could do with a wider field, if only to capture the extended dark nebula B168, whose eastern lobe IC5146 sits in, and which is only vaguely indicated in these images.

The lower image is a false colour version of the one above, just because I can, really. Click on either to enlarge.

Comet Ikeya-Zhang

2008-07-19T20:40:00.001+01:00

Object: 153P Ikeya-Zhang

Type: Comet
Constellation: Pisces

Date: 21 March 2002
Equipment: Casio digital camera, afocally coupled to 25mm eyepiece, VC200L

Subframes: 6 x 60 second, unguided, no darks or flats.

This beauty was clearly visible to the naked eye even though it was only 9 degrees above the horizon when I caught it. The photograph gives a good impression of what it actually looked like through the eyepiece - the beauty of afocal photography.

The Crescent Nebula

2008-07-18T20:20:00.002+01:00

Object: NGC 6888 (Caldwell 27)
Type: Nebula
Distance: 4700 light years
Constellation: Cygnus
Date: 26 August 2005
Equipment: SXV-H9, 114mm f5.6 Vixen refractor
Subframes: 12 x 180 second, unguided, no darks or flats.

Another one to get around to re-doing now I have a bit more experience AND a hydrogen alpha filter. This object just cries out for more and longer subs to do it justice. Still, not bad for an early attempt.

Venus/Moon conjunction

2008-07-17T20:15:00.003+01:00

Possibly my first astrophotograph ever, which I recently found in an old photo wallet and scanned in. It's dated 29 December 2000, with a time of 18.00. A quick glance at a SkyMap Pro chart for that time shows Venus with a phase of 60% and the Moon with a phase of 14%, and suggests the two star visible between the overexposed Venus and the Moon are Delta and Gamma Capricorni.

The shot was taken with an Olympus OM2 and a 300mm telephoto lens, 1 second exposure at f5.6 on Kodak Gold 200.

The North America Nebula.

2008-07-16T01:03:00.000+01:00

Object: NGC 7000 (Caldwell 32)
Type: Nebula
Distance: 1800 light years
Constellation: Cygnus
Date: 16 August 2005
Equipment: SXV-H9, 135mm Zeiss telephoto lens
Subframes: 30 x 300 second, unguided, no darks or flats.

The SXV-H9 works fine with a telephoto lens, even given the theoretical undersampling. The adjacent Pelican Nebula (IC 5067) can also be made out at the top of the image (click to enlarge).

The Dumb-bell Nebula.

2008-07-15T00:48:00.000+01:00

Object: Messier 27 (NGC 6853)
Type: Planetary Nebula
Distance: 815 light years
Constellation: Vulpecula
Date: 17 July 2005
Equipment: SXV-H9, f5.6 refractor
Subframes: 14 x 120 seconds. Unguided, no darks or flats.

Another summer beauty from the evening of 17 July 2005, recently reworked with AstroArt 4. Click on the image to enlarge.

The Great Hercules Globular Cluster.

2008-07-14T00:28:00.000+01:00

Object: Messier 13 (NGC 6025)
Type: Globular Cluster
Distance: 23400 light years
Constellation: Hercules
Date: 17 July 2005
Equipment: SXV-H9, Vixen f5.6 refractor
Subframes: 20 x 60 seconds, 20 x 150 seconds, all averaged. Unguided, no darks or flats.

Mixing in the shorter subframes with the longer ones seemed to avoid the "burnt out" core I've seen in some images of this object. M13 really seems to benefit from the use of the digital development tool in AIP4Win, and gives nice tight star images in the main cluster itself.

I highlighted the 16th magnitude galaxy IC 4617 that also showed up on the image (click to enlarge).

Visually, I don't think the "great" M13 globular cluster packs the visual punch of M5 in Serpens, which I hope to get around to imaging one day, but through the 8 inch VC200L it's still one of the few objects that actually gets a "wow" out of my astro-apathetic and long-suffering wife.

NGC 4565.

2008-07-12T00:15:00.000+01:00

Object: NGC 4565 (Caldwell 38)
Type: Galaxy
Distance: 32 million light years
Constellation: Coma Berenices
Date: 08 May 2005
Equipment: SXV-H9, VC200L
Subframes: 30 x 30 seconds, 2x2 binned. Unguided, no darks or flats.

A final image from the, by then, gale force evening of May 8th, 2005. I cut the exposures down to 30 seconds to try and get at least some subs that hadn't been blurred by a wind-blown telescope, and I was absolutely amazed to find that AstroArt 4 was able to wring out some detail on what appears to be virtually blank frames. Click to enlarge.

The Blackeye Galaxy.

2008-07-10T00:02:00.000+01:00

Object: Messier 64 (NGC 4826)
Type: Galaxy
Distance: 13.5 million light years
Constellation: Coma Berenices
Date: 08 May 2005
Equipment: SXV-H9, VC200L
Subframes: 28 x 60 seconds, 2x2 binned. Unguided, no darks or flats.

Another image from the windy evening of May 8th 2005, that has also benefitted from reworking with AstroArt 4. Click to enlarge.

The Whirlpool Galaxy.

2008-07-09T23:41:00.000+01:00

Object: Messier 51 (NGC 5194 & 5195)
Type: Interacting Galaxies
Distance: 15 million light years
Constellation: Canes Venatici
Date: 08 May 2005
Equipment: SXV-H9, VC200L
Subframes: 12 x 60 second, 2x2 binned. Unguided, no darks or flats.

A very windy evening and a long focal length meant shortish exposures to avoid trailing, and lack of experience and only the clunky Starlight Xpress processing software to work with at the time meant no darks or flats. I shot about 50 subs, but only the 12 were usable thanks to the wind blowing the 'scope around and blurring the images. This image is a reprocess using my recently-acquired Astroart 4 software, which allowed me to zap some residual trailing on the final stack with the nifty deconvolution filter, resulting in a half-decent image (click to enlarge).

Definitely one to revisit on a less windy night.

Comet Machholz

2008-07-08T23:14:00.000+01:00

Object: Comet Machholz
Date: 02 January 2005
Equipment: SXV-H9, Vixen f5.6 refractor
Subframes: 6 x 1 minute, averaged. No flats or darks.

A fairly crummy image that in hindsight needed more subs of longer exposure and flat field correction. Click to enlarge, which shows up the dust donuts and noise. High cloud rolled in just after I got set up, which is why I didn't take more subs. However, it's unlikely I'll get a chance to have a second go at this one as the next perihelion is due in the year 115470.

I caught this as it was zipping through Taurus. Through the eyepiece it was around magnitude 4 and exhibited a strong greenish colour. The above image just about shows the dust tail curving off to the northeast, whereas the ion tail can just be seen as a straight 'V' pointing away to the east (left).

The image was stacked on the nucleus, hence the trailing stars.

The Crab Nebula.

2008-07-07T22:46:00.000+01:00

Object: Messier 1 (NGC 1952)
Type: Supernova remnant
Constellation: Taurus
Distance: 6500 light years

Average of 16 90 second sub-frames acquired on the evening of 30 December 2004 using a Starlight Xpress SXVH9 and the Vixen f5.6 refractor, all stacked and processed in AIP4Win and PSP7. Click on any of the images to enlarge.

Crop and enlargement of the first image. Some of the filamentary structure can be seen despite the relatively low focal length and resolution.

This was a much earlier effort from about two years previous, using a "prosumer" digital camera coupled afocally to a 25mm eyepiece on the VC200L. This is an average of six 1 minute frames, processed in AIP4Win and PSP7.

IC1805 & IC1848

2008-06-27T18:41:00.000+01:00

Back in December last year, I set out to make a wide-field image of this area in Cassiopeia, to include both of these spectacular nebulae in one frame. I've only just got around to working them up (click on any of them below to enlarge).

The SXV-H9 camera on a 135mm camera lens gives a 3.5 by 2.5 degree field, allowing wide-field imaging with quite modest equipment. Mosaicing frames allow even wider field images to be assembled. Images above and below are stacks of 30 x 300 second frames of the adjacent nebulae in Cassiopeia, IC 1805 and IC1848, taken on consecutive nights. Exposures were 2 x 2 binned and taken in H-alpha. The binning was needed to get the exposure time down as I wasn't guiding, but it doesn't seem to have affected the resolution too badly.

After stacking and stretching in AIP4Win, I imported the separate images as layers into a Paint Shop Pro image frame that was large enough to contain both frames. I used the "eye dropper" tool to measure the brightness of each frame and adjusted the brightness and contrast of the images so that the grey background of each image had the same value. I try and aim for RGB values of 10-15 in the darkest parts of monochrome images. I then rotated the IC 1805 ("Heart Nebula") image until corresponding stars could be overlapped in each frame and then "selected" the IC 1805 area with a "feather" of about 15 pixels, pasting it onto the IC 1848 frame. The images were slid about until the stars overlapped (I change the top layer to "exclusion" mode so that star images vanish when perfectly aligned, and then restore to "normal" when a match is obtained) and then the layers were merged and cropped to give the final wide field pair as below.

Whilst these images can never match those taken with big-chip CCDs and wide-field apos, I still think their quality is still quite reasonable.

The Rosette Nebula (NGC 2237,8-46)

2008-06-05T18:04:00.000+01:00

30 x 180 second subs through a 300mm telephoto lens (another boot sale purchase) of unclear (possibly Russian) make, using an SXV-H9 in 2x2 binned mode and a Astronomik hydrogen alpha filter. I took these during the evening of Feb 3rd. 2007.

The images were calibrated with a master flat but no darks (I applied a mild median filter to the raw subs instead) and then stacked in AIP4Win. I imported the stacked image into Paint Shop Pro and applied a mild "edge preserving smooth" to smooth out a bit of noise and give the monochrome below.

I couldn't resist messing about with layers and colour masks in PSP to give the false colour image above. Click on either image for a bigger version.

I alway think that images of this nebula conjure up a picture of a giant, ghastly skull, with the cluster NGC 2244 nestling in its right eye socket.

IC1396

2008-06-01T18:32:00.000+01:00

2,200 light years away in Cepheus lies IC1396, a vast sprawl of faint nebulosity that occupies five moon diameters of sky as seen from Earth. I imaged this during the evening of Sept. 20th 2006, using the SXV-H9 through a 135mm Zeiss lens I picked up at a boot sale for £3.

22 X 4 minute subs were taken in 2x2 binned mode, and processed in API4Win. 16 flats/flat darks and 16 dark frames were used in calibration. The final stacked and calibrated frame was Gaussian stretched and Van Clittert deconvoluted using the API4Win default settings, to give the final monchrome image below. The top image is a "false colour" one put together in Paint Shop Pro, just because I can. I think I prefer the monochrome one (click on the images for larger views).

The formation called "The Elephant's Trunk", a curious column of bright and dark nebulosity, is clearly visible just right of centre (north is up, west is to the right). The bright star in the northeast part of the image is Mu Cephei, Herschel's "Garnet Star".

Venus Transit, June 2004

2008-05-26T17:37:00.000+01:00

June 8th, 2004 presented a once-in-several lifetimes opportunity to witness a Venus solar transit. They occur in pairs, 8 years apart, with 122 years between the second of one series and the first of the next. The next one is due on June 5th. 2012, but occurs after sunset in the UK and so won't be visible unless you go to Japan or somewhere like that.

Historically, these events were of tremendous importance, with accurate timings being used to try and calculate the distance of the Earth from the Sun. In his book Venus, (2002, Cassell Illustrated, ISBN 0 304 36281 6) Patrick Moore gives a fascinating account of the various travels and travails that early observers went to to witness these events. These days, they are observed more for fun rather than for any scientific purpose.

For my own part, I fitted my Vixen ED114SS with a Baader solar film filter and used a digital camera held up to the eyepiece to take the various shots shown here. The Baader film gives a white light image and I added a yellow mask in Paint Shop Pro to make them look pretty, but other than rotating or cropping, not much processing was needed to clean up the images I gathered.

The image above is a combination of shots taken roughly every hour, from around 6.30 to 12.15 BST, with the camera held up to a 25mm eyepiece. Two tiny sun-spots can be seen in the centre of the Sun's disc (which made job of the aligning the layers for the composite frame a lot easier!)

The sequences below used a 9mm eyepiece.

The sequence above shows the contact of the western and then eastern limbs of Venus with the eastern limb of the Sun. The two frames just before second contact clearly show the dense Venusian atmosphere lit up from behind by the Sun's glare.

Similarly, the second sequence above shows the contact of the western and then eastern limbs of Venus with the western limb of the Sun. Again, the two frames just after third contact show the Venusian atmosphere lit up from behind by the Sun's glare, although not as clearly as at second contact. By then, a high haze had set in, diminishing visibility.

However, both the weather and the actual timings were kind to observers in my south-east corner of the UK, and I was able to witness the whole event. Observers from other locations weren't so lucky.

Because my eastern horizon is a bit cluttered from where I normally observe, early that morning I took the scope out to a farmer's field in what I thought was the middle of nowhere (after having OK'd it with the farmer first - our local man takes no prisoners if he thinks he's going to be a victim of fly-tippers!). I was nevertheless surprised at the steady stream of ramblers and cyclists who stopped by for a look through the eyepiece, even in my comparatively lonely and remote location. At one point, I had a queue of about six or seven folk, all wanting to see the rare celestial event. Most had heard about it on the news and I was only too pleased to let these passers-by satisfy their curiousity.

You can never be truly alone these days in the busy and crowded south-east, I guess...

M57 - The Ring Nebula

2008-05-25T19:13:00.001+01:00

The Ring Nebula in Lyra is another old favourite of astroimagers. The above image (click on the image to emlarge) was taken in September 2007 with the SXV-H9 camera and the Vixen VMC200L (200mm/f9) and was assembled from 20 X 60 second exposures in white light as a luminance frame, with 30 X 60 exposures through a Ha (red channel) filter, with a further 30 X 60 exposures through an O3 (blue channel) filter, all in 2x2 binned mode. The raw frames for each channel were stacked and contrast-adjusted in AIP4Win, then exported as TIFs to Paint Shop Pro, where I used the colour masking technique in "Layers" as described earlier to assemble the final colour image as above.

I had a little difficulty focussing and wasn't too happy with the final star images. After the imaging session, I replaced the CCD with an eyepiece and found that the 'scope was actually rather out of collimation. This was the first time in five years that I had needed to tweak the collimation on the VC200L - it has a double set of push-pull screws to adjust both primary and secondary mirrors, which tend to lock the mirrors in place and keep collimation pretty well. However, I remembered that I had hastily abandoned my last imaging session when a sudden rainstorm had hit, and that I had to remove my rig from its platform and wheel it to shelter pretty quickly when the first big drops of rain started to fall. I guess the hurried lumping and bumping about hadn't done the optics much good.

These compound VC200L scopes aren't the easiest things to collimate, but fortunately there's a good guide here. A few tweaks with an Allen key on the primary mirror adjustors soon got the star images sharp again, and I plan to return to M57 and try to get a better resolved image.

Even so, the image above still shows the 15th magnitude barred spiral galaxy IC1296 to the northwest of M57 - most images you see don't go deep enough to evidence it, especially those taken with digital cameras.

My own earlier (August 2002) effort with a digital camera (afocal projection using the VC200L and a 25mm eyepiece) is shown below (click to enlarge).

This is an average of two 60 second exposures taken at ISO400 and processed in PSP. I haven't adjusted the colours at all, only the contrast and brightness. Whilst the digital camera is noticably less senstive than the SXV-H9 and shows fewer stars, the image itself is still quite satisfying.

M42 - The Great Orion Nebula

2008-05-23T18:57:00.000+01:00

M42 is always the first object a budding astroimager most wants to capture, and I was no exception. The shot above was the first and last attempt I ever made at capturing deep sky images with emulsion flim, back in January 2002. It was a 10 minute prime focus exposure on Kodak Gold ISO200 film using an Olympus OM1 mounted on the back of my VMC200L. Maybe some folk out there are capable of accurate manual guiding, but I reckon that the only way to really make film photography work for you at long focal lengths and long exposures is with an autoguider, which I don't have.

When I finally bought a digital camera, this gave me the option of digitally processing much shorter exposures (up 60 seconds) at higher sensitivities (ISO400 or even 800), avoiding to a certain extent the guiding problems. Even so, maybe half of the frames I took in my early sessions still showed signs of trailing. It was then that I learned the importance of polar alignment!

Once I got the hang on my GPDX's alignment scope, then there was the ever-present problem of sky-glow and camera noise to deal with. Five years ago before the advent of low-noise chips, decent internal camera software and CMOS devices, digital cameras were REAL pixel monsters. Here's one frame out of a useable batch of around eight that I acquired from a session in December 2002.

Click on the image (or any other for that matter) for a larger view, that shows the noise and vignetting. The vignetting (the dark corners of the frame) arises from the afocal mounting of the camera, which was fixed to peer down a 25mm eyepiece on my VMC200L by means of a home-made bracket. I never tried making flat frames as the field of view was so wide that I simply cropped out the edges in Paint Shop Pro. Similarly, the noise vanishes with a click of the "Despeckle" option.

Removing the sky-glow and beating down background noise is a bit more challenging. I've reworked many of my old digital camera astro photos with AIP4Win since I've had it, as to be honest, stacking multiple images in PSP7 was a pain and never too successful in my hands. Importing a batch of despeckled frames into AIP4Win brakes the colour images down in to individual LRGB FITs elements, each of which can then easily be stacked to give quite smooth L, R, G and B frames.

The image above is a stack of 7 frames, all disassembled and stacked as individual LRGB frames, and then exported back into PSP as TIFs (I don't think the colour stacking part of AIP4Win v1 is much good, so I use PSP). I merge these the black and white TIFs representing the red, green and blue frames with red, green and blue overlay frames to restore colours and give R,G and B TIFs.

Each colour TIF is loaded into a new frame as a layer (with the luminance one as the bottom layer), which you can then move around to align and then adjust transparencies using the "layers" function in PSP. I guess the colours are subjective - I always think M42 looks slightly greenish through the eyepiece, so I just chose a combination of layer intensities that I thought was the most astheticially pleasing.

With the purchase of a Starlight Xpress SXV-H9, the Orion Nebula was again one of the first objects I wanted to try out. The image below was taken with the SXV-H9 and 4.5 inch refractor, and is an average of 10x15s, 10x30s and 6x60s exposures all at full camera resolution, stacked and processed in AIP4Win.

I wanted to avoid the "burnt out" look you see in a lot of images of M42, where the bright Trapezium area gets overexposed in the attempt to capture the fainter outer nebulosity. Using a stack of shorter exposures in with longer ones has achieved this.

The SXV-H9 is a monochrome device, so if you want colour images you can shoot additional frames through red, green and blue filters, or you can do what I usually do for extended objects like nebulae, and cheat. I have a colour filter wheel, and although you can use 2x2 and even 3x3 binned exposures on your RGB frames to cut down times, I find that using artificial colour masks on monochrome frames gives results that are almost as pleasing in practice.

Below is a monochrome frame blended with a red frame in PSP7. Basically, I make a new file in PSP7 that's the same size as the monochrome, select a nice red colour from the colour pallet, flood fill the new frame and then copy and paste the monochrome one over the top. Using the "Layers > Arrange > Move down" option, I send the monochrome layer to the bottom, and in the layer pallet select "colour" as the blend mode. Somewhere around the 50% blend mark gives you a nice red nebula without red stars.

I then repeated the process for a frame consisting of an average of the 15 second exposures alone, to give a green frame as below:

Blending the two, again using the layer pallet, with the red layer as the bottom one and the green layer as the top and set to "color" in the blend mode, gives you a frame that has the central Trapezium region showing good detail and that hint of green you see visually. Final adjustment in "Curves" to tweak back the RGB and red channel brightness levels gives you a pleasing picture, I think..

Colours in deep sky objects are, of course, largely subjective. Only the very brightest, such as M42, show any colour at all through moderate aperture telescopes, and then that tends to be just green. I'm not a fan of the garish images you see in a lot of the astromony magazines, especially those in "mapped" colour (where Ha is often assigned to the blue channel, making everything look plain weird).

It's all in the eye of the beholder, and often, monochrome images often look the best.

Saturn occultation, 03 Nov. 2001...

2008-05-03T20:30:00.001+01:00

I've always found these events fascinating. The occultation of Saturn by the Moon on 3rd. Nov. 2001 gave me an opportunity to try and image the event. The technique was quite simple - I held my digital camera up the a 9mm eyepiece on my VC200L, pressed the button and hoped! I didn't make a record of the exposure time, but the lunar portion of the image came out OK.

It took a lot of playing in Paint Shop Pro to get Saturn to stand out, it being so much dimmer than the illuminated edge of the Moon. A pale band on Saturn is just visible (click on image to get a bigger view).

On the emergence, the contrast (and thus the image processing required) was a lot less extreme. The Cassini division is just visible in Saturn's rings.

I was quite pleased with the results, even though the imaging technique itself was fairly simple.

Setting Up...

2008-05-02T19:39:00.000+01:00

I don't have space for a permanent observatory but if I did, chances are the local chavs would break in and steal or smash stuff up anyway, just because they can.

Setting everything up from scratch for an imaging session is quite time-consuming, and so I built a mobile platform that supports the mount and houses the power supplies for the drive, the CCD camera, the laptop and dew heaters.

The mount and pillar assembly is held onto the top of the box by a stout spring that runs down the tube of the mount pillar and through the top of the platform. This allows some levelling adjustment via the pillar legs but holds the pillar in place firmly enough to stop it moving about during movement of the platform.

The plaform fits on a dolly (see above) that is rolled from my (alarmed) garage to a hard-standing platform at the bottom of my drive, which offers a reasonable south-facing view and which is also fairly well sheltered from street lights and neighbour's security lights. The platform slides off of the dolly and on to the hard-standing area (both are fitted with plastic furniture runners). Once I've got the platform box in place, all I have to do is plug the box into a mains extension, do a polar alignment on the mount and then fit the 'scope, and I'm ready to do my alignments with the "GoTo" Skysensor.

The platform has some locating bars so it goes back in roughly the same place each time, but I use the polar alignment scope in the GPDX to get a reasonable polar alignment that is usually good enough for the 2-3 minute exposures I usually use with the 600mm refractor. I can get away with up to 90 second exposures with the VC200L without noticeable star-trailing if I run the Skysensor PEC, sometimes more if I get lucky with the polar alignment.

The lap-top sits on a roll-out shelf for ease of access (see above)

I do have a guide camera but to be honest I've never found the time to optimise the settings for it. Maybe a job for this summer.

If I get a good three-point alignment, I usually slew to the chosen object for the evening and then ask the Skysensor to find me a nearby brightish star for focussing and accurate alignment. The SXV-H9 software has a nifty little screen that allows you to sample every second for focussing, and I simply adjust the focusser manually until I see the sharpest possible star on the laptop screen. When I've focussed, I use the image on the screen to track the star while I run the PEC programme. I can then use the GoTo function to send the scope to the object. It usually falls on chip first time.

I take a few shots in 3x3 binned mode, with the minimum time needed to show the outline of the obejct in question. That allows me to accurately frame the object before I start acquiring frames for imaging purposes. I run a few long exposures to see how long I can get away with before star trailing sets in, and set the camera to acquire maybe 50 or 60 raw frames. Often as not 2x2 binning provides adequate resolution for most objects, although I'll always go for full resolution if the object is bright enough.

It usually takes about 45 minutes from me deciding to start imaging to actually starting.

My drive is gated and so I usually feel comfortable with leaving the equipment to do its stuff, if I'm not out there actually observing visually with my other scope (I have a CG5 manually operated mount that I use for visual work).

I never bother with dark frames as the SXV-H9 camera doesn't generate much noise - I usually take out the few noisy pixels there are with a median filter during processing. I take flats after I finish imaging - I wheel the whole set-up back into my garage, point the telescope at a large square of white polystyrene sheet fixed on the wall and take 16 flat frames. I also shoot the same number of flat darks. The garage lights seem to light up the sheet pretty evenly and the flats come out with no visible gradients once they are all dark subtracted and averaged.

Suburban Skies...

2008-05-01T19:31:00.000+01:00

The first telescope I ever owned was one I made when I was about ten years old. I pinched the lens out of my Dad's magnifying glass, and the eyepiece out of a toy microscope I had, and mounted them in a cardboard tube. There was a half-Moon that summer evening, and I was so fascinated by the lunar landscape that my Mum had to virtually drag me in to go to bed. I was hooked.

A few years later, the Miner's Strike in 1972 resulted in widespread power cuts, and it was the only time that I can ever recall seeing the Winter Milky Way so clearly, high above Orion, shining in the sky like a glittering, pale silver carpet. Venus, low in the west, was so bright it cast shadows. That Christmas, Mum and Dad had bought me a 10 x 50 pair of binoculars and a Phillips Planisphere, both of which I still have and still use, although my own 10 year old son has come to regard them as his own. I spent many hours that year, scanning the evening sky and learning the constellations.

Then came the world of work, and for over twenty years I neglected the sky above for the more mundane issues related to earning a living. It wasn't until my own son was born that I started looking at the night sky again.

I can't remember what catalysed the decision to buy a "proper" telescope. I do remember getting a good bonus that year, and with my partner's permission, I decided to buy a Vixen VC200L, with a "GoTo" drive unit. What an amazing instrument. I was transported back to my childhood in many ways, only this time I had thousands of deep sky objects to view, often in breathtaking detail.

My first sights of M57, M13, the Orion Nebula and the rings of Saturn showing the Cassini division led me to spend many more hours under the night sky, on some occasions from dusk to dawn. Needless to say, my better half put her foot down about these all-night marathons, especially as at the time I was travelling a fair distance to work every day.

It was only a matter of time before I tried my hand at astrophotography. My first efforts at emulsion photography with the VC200L were pretty awful, but digital cameras were just becoming available for the first time. I finally bought a 3.3MB (which at the time was a "wow") camera, and never touched a film camera again.

My first astrophotograph with a digital camera is above. It was taken in late 2001, I don't have a date. I do remember that I just speculatively pointed the camera at the 25mm eyepiece I had trained on the nearly-full moon, and being astounded at the detail that subsequently emerged on my computer screen.

I've never looked back. For three years I imaged all sorts of objects, simply by mounting the camera on a home-made bracket that clamped on the eyepiece of my VC200L. That camera was capable of 60 second exposures at ISO 400 or 800, although the noise these early cameras generated for such frames was horrendous. Some of the results were quite encouraging however, and I certainly learnt my way around PaintShopPro 7 as the imaging processing software to clean up my noisy, light polluted raw frames.

But when my old digital camera finally died, I finally treated myself to a Starlight Xpress CCD.

This is in a different league, and it's an instrument I'm still learning to get the best out of.