The Christmas Tree Cluster

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.