M67

[alan4908]

I decided to try a LRGB image of the open cluster M67 since I quite like the "glowing" effect that the Lum channel provides on the stars, in addition, it also helps to capture any dim fuzzies that may be lurking in the background. 

I selected 300s sub exposures, down from my normal 600s, to avoid excessive star bloat. To maximize star colour, I also decided to process the image using two different DDP stretches of the Lum, a high one, targeting the dim objects and one low, targeting the bright stars. The result image was then blended together in PS with an appropriate mask. 

The cluster is unusual in that it is incredible ancient (c3billion years), somehow, it has resisted the gravitational forces which tend to disperse most open clusters over several hundred million years. As a consequence, M67 has more yellow/red and less blue stars than younger open clusters. 

The image below represents just under 3.4 hours integration time and was taken with my Esprit 150. 

Alan

LIGHTS: L:9, R:13, G:9, B:10 x 300s, DARKS:30, BIAS:100, FLATS:40 all at -20C.

[michael.h.f.wilkinson]

Lovely image and great write-up. I didn't know that M67 was in the same exceptional class of open clusters as NGC 188 (Caldwell 1). That has also resisted the tidal effects that generally disperse open clusters

[alan4908]

11 hours ago, michael.h.f.wilkinson said:

Lovely image and great write-up. I didn't know that M67 was in the same exceptional class of open clusters as NGC 188 (Caldwell 1). That has also resisted the tidal effects that generally disperse open clusters

Thanks for the comment Michael .

It does seem amazing that certain open clusters can avoid gravitational dispersal effects for so long.

Alan