Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Mar 24, 2009, 21:26:03

Title: M44 the Beehive cluster
Post by: RobertM on Mar 24, 2009, 21:26:03
This is a very open cluster in the constellation of Cancer.  It is visible as a moderate fuzzy blob just north east of the star Asellus Australis (Delta Cancri). The cluster itself is approximately 600 million light years away and 600 million years old.  It is thought to share the same origin as the Haydes cluster in Taurus.

This image was taken with a Canon 450d DSLR with Astronomik CLS clip filter and Takahashi Sky 90 refractor operating at approximately f/4.5.  A total of 10 x 2 minute unguided subs were combined in producing this image.  Stacked, resamples and colour balanced in MaximDL, the rest of the processing in PS.

Took this one last night after reassembling the mount and telescopes on the pier.  This was captured using MaximDL using dithered subs which seems to have helped with the hot pixels (I think).

The colours don't look right, certainly not the same as it looks in PS - anyone any adeas ?

JPEG'd
(http://farm4.static.flickr.com/3585/3383446216_31d4187a93_b.jpg)

Full size:
http://farm4.static.flickr.com/3585/3383446216_e6658a2318_o.jpg (http://farm4.static.flickr.com/3585/3383446216_e6658a2318_o.jpg)
Title: Re: M44 the Beehive cluster
Post by: MarkS on Mar 24, 2009, 22:51:56

Hmm, you're right  - it doesn't look quite right.

A similar question has come up before - does this help?  http://forum.orpington-astronomy.org.uk/index.php?topic=4226.0

Mark

Title: Re: M44 the Beehive cluster
Post by: RobertM on Mar 25, 2009, 07:16:25
Thanks Mark, I'd forgotten about that little titbit.  Will give it another go tonight.
Title: Re: M44 the Beehive cluster
Post by: RobertM on Mar 25, 2009, 18:23:13
Beehive reprocessed, trying to bring out some colour...

(http://farm4.static.flickr.com/3537/3384868925_3e6f1f2883_b.jpg)

Full size: http://farm4.static.flickr.com/3537/3384868925_66c789302b_o.jpg (http://farm4.static.flickr.com/3537/3384868925_66c789302b_o.jpg)
Title: Re: M44 the Beehive cluster
Post by: Fay on Mar 25, 2009, 21:17:01
Robert, I think it is really facinating, the age & distance of the Beehive.
Title: Re: M44 the Beehive cluster
Post by: JohnP on Mar 25, 2009, 21:58:47
One of my fav's as well - It was the first thing I actually found with Bino's when I first got into Astronomy...

Like the wide FOV - John
Title: Re: M44 the Beehive cluster
Post by: Mike on Mar 26, 2009, 11:44:37
Nice image Robert. The stars are a bit on the purple side though.
Title: Re: M44 the Beehive cluster
Post by: Ian on Mar 26, 2009, 12:02:45
it does appear to be weighted a bit too much towards the red. Was the red a bit out of focus?
Title: Re: M44 the Beehive cluster
Post by: RobertM on Mar 26, 2009, 12:40:37
Thanks for the comments, will have another go calibrating on a G2V star.  I did do a quick manual focus so it's more than likely that is slightly out.  I have also noticed a slight colour change from blue to red when moving past perfect focus with the canon lens so maybe a similar thing is happening here.  Another problem is that the core of a saturated star will always appear white making the colour difficult to bring out, I need to work out a way of resolving that one too.  The Beehive is an ideal subject to experiment on - no fuzzies or nebulae to get in the way.