Coma Berenices Open Cluster

[cloudsweeper]

Further to my recent post which included this (sorry for a slight repetition), I just wanted to add a comment.

I had been aware of this object via Stellarium, but it didn't feature in the 8SE's handset database, so I never got round to trying for it.

Anyway, I have been proven wrong - it is in the database under Stars > Asterisms.

Turns out that it is not in the IC or NGC catalogues because it was considered very large, and it had not been established as an open cluster, just perhaps a star cluster - a few dozen stars in an attractive, large, loose, cluster.

Well I located it yesterday using hopping and the ST120 frac., and I'm glad I was using that 'scope, because the cluster is 6 or over 7 degrees (depending on source), and I was viewing over 4 degrees of it, and scanning around the region.

So there it is - an open cluster of a few dozen stars, well worth seeing, especially in a widefield 'scope of course.  It has a characteristic "V" pattern of stars.

Also known as Melotte 111 and Cr 256.  Highly recommended!

Doug.

 

 

 

[goodricke1]

Yes this is one of my favourites too and I'm always surprised how it seems to get overlooked as a naked eye showpiece; from a dark rural sky it consistently diverts my attention even if I'm looking 40 or 50 degrees away. And through binoculars it's one of the most rewarding areas of the entire sky.

[cloudsweeper]

Being at least 6 degrees in size, it must be amongst the largest of easy-to-see objects, if you don't include constellations, asterisms, and large areas of nebulosity.

Any other contenders??

Doug.

[Cosmic Geoff]

It deserves to be better known. Best seen in binoculars - narrow field scopes are ill-suited for the task. I'm not surprised it's left out of the database for  a Nexstar C8 SCT.

[cloudsweeper]

10 minutes ago, Cosmic Geoff said:

It deserves to be better known. Best seen in binoculars - narrow field scopes are ill-suited for the task. I'm not surprised it's left out of the database for  a Nexstar C8 SCT.

The ST120 did it some justice with a TFOV of about 4.5 degrees, although the whole object is 6 or 7 degrees wide!

I did find it in the 8SE Database under Stars > Asterisms, although I wasn't using that 'scope when viewing it.  It's all very well being in the GoTo Database, but - as with other very large objects - you'd need to scan around, which takes some of the pleasure away!

Doug.

[Pondus]

Coma Starcluster is a Nice one and a certainly big cluster.

Hyades is a good contender (for big open clusters), its definitely one of my faves.

 

Rune

[cloudsweeper]

13 minutes ago, Pondus said:

Coma Starcluster is a Nice one and a certainly big cluster.

Hyades is a good contender (for big open clusters), its definitely one of my faves.

 

Rune

Thanks, Rune - Hyades is indeed a contender at about 5.5 degrees, and its stars are generally brighter since it is relatively close by.

A widefield 'scope like the ST120 is great for enjoying these sights.  Different 'scopes for different targets, of course!

Doug.

[DeepSkyBagger]

273 stars are recognised as members of this cluster, but if you asked me to point at them, I might struggle! It's one of the closest open clusters to Earth, at just 260 light years. It has a Trumpler classification of III3r, meaning that it is detached from its background (ie easy to spot), but has no noticeable central condensation (that's obvious in bins); there is a wide magnitude range in the member stars (ie it contains bright, medium and dim stars), and it is rich (>100 stars). Because it's so near and so appears so big, all the earlier observers overlooked it. It also bears the designation Collinder 256.

[mdstuart]

Another cluster that is often overlooked...as it does not have an M or even N number is IC4665.

Lovely cluster in Opiuchus.

http://www.capella-observatory.com/ImageHTMLs/OpenClusters/IC4665.htm

Its above and right of Saturn late in the evening at the moment - best in binoculars like the Coma Berenices cluster.

Enjoy and report back

Mark

[johnfosteruk]

The Coma Star Cluster is a beauty, I had stunning binocular views a few months ago. I counted a few dozen members. I need to put a wider setup on it, I want to see it all in the one FOV so thanks for the reminder Doug.

[cloudsweeper]

On 2017-6-3 at 14:04, mdstuart said:

Another cluster that is often overlooked...as it does not have an M or even N number is IC4665.

Lovely cluster in Opiuchus.

http://www.capella-observatory.com/ImageHTMLs/OpenClusters/IC4665.htm

Its above and right of Saturn late in the evening at the moment - best in binoculars like the Coma Berenices cluster.

Enjoy and report back

Mark

Thanks, Mark - yes, the Summer Beehive Cluster - a nice, loose, large, bright cluster, which (with the correct orientation) seems to be saying HI!

Thought I'd have a return viewing this evening, and was enjoying Mare Imbrium beforehand when the clouds rolled in and put paid to the session!

Doug.

[Pondus]

2 hours ago, cloudsweeper said:

 yes, the Summer Beehive Cluster - a nice, loose, large, bright cluster, which (with the correct orientation) seems to be saying HI!

Its a very nice cluster indeed, but pretty difficult to pick up from 59N. Under astronomical darkness that is.

Too many objects get washed out by the bright summer nights unfortunately, even the brighter ones .

 

Rune

[Special K]

Easily impressive giant!  I've seen this naked eye at a very dark location and was very pleased. Then scanned it with bins.  It's very busy in places making it a great browsing target.

[andrew63]

Thought I'd have a look at the cluster tonight as it's heading rapidly west. It was ok in the wide field refractor but as you say, much more satisfying in binoculars - a lovely sight.

 

andrew