Open clusters?

[_leo_]

Hi,

This season I want to explore more open clusters.

I have seen the E.T cluster and the muscleman cluster, as well as the pleiades, hydra cluster,the moving cluster and the double cluster.

What other clusters are there to view that would be ideal for beginners?

Thanks.

 

[Stu]

5 minutes ago, _leo_ said:

Hi,

This season I want to explore more open clusters.

I have seen the E.T cluster and the muscleman cluster, as well as the pleiades, hydra cluster,the moving cluster and the double cluster.

What other clusters are there to view that would be ideal for beginners?

Thanks.

 

There are plenty more in Cassiopeia to try for eg M103, NGC659 and 663. When Auriga and Gemini are better placed you have M35,36,37 and 38 to go for. M11 in Scutum is very nice, plus the Coathanger in Vulpecula. Loads to go after.

[_leo_]

3 hours ago, Stu said:

There are plenty more in Cassiopeia to try for eg M103, NGC659 and 663. When Auriga and Gemini are better placed you have M35,36,37 and 38 to go for. M11 in Scutum is very nice, plus the Coathanger in Vulpecula. Loads to go after.

Thanks for these Stu. I forgot to mention the coathanger, this is the one that got me interested in the clusters.

[Zermelo]

https://www.astroleague.org/al/obsclubs/opencluster/opencluster1.html

(scroll to the bottom for the link)

I'd vote for the Beehive. It won't be too long before it's well placed at a civilized hour.

[Nyctimene]

NGC 7789 in Cas, "Caroline's Rose"; easy to find, a very dense oc, needs magnification and is magnificent; my most loved oc

NGC 6811 in northern Cyg, "Hole in a Cluster";  about 6° SE of it NGC 6866, the "Kite Cluster"

M 47/M46  in Pup with the embedded planetary 2438 (will need a OIII or UHC filter)

M 35 in Gem, with the dense 2158 close W

Stephan

 

 

 

[Stu]

3 hours ago, _leo_ said:

Thanks for these Stu. I forgot to mention the coathanger, this is the one that got me interested in the clusters.

No problem. The Coathanger is great, isn’t it? You’ve already found NGC457 which is one of my favourites.
 

What are your skies like, and what scope do you have? Caroline’s Rose that Stephan suggested is wonderful but I think needs a decent sky to show its best.

[Pixies]

The open clusters in Auriga are coming into the winter sky now. M36, 37 and 38. M37 is the best I think - looking more like a globular cluster You can see them as blurry blobs in binoculars but get a scope with x75 on them. 

M37:

(image from wikipedia)

Nearby is NGC1664 - the "Kite Cluster". My favourite OC. I think it looks like a stingray:

(image from the sky live)

and not forgetting the Christmas Tree cluster (NGC 2264):

(from Twitter. it's really hard to find an image without all the nebulosity from astrophotography)

 

 

[_leo_]

Thanks for all these new clusters to find, it should keep me busy for a while!

@Stucoathanger is nice, but my favourite so far is also ngc 457.

I would say my sky is bortle 7/8

My current telescope is a SW Heritage 130p 

[Stu]

Good stuff @_leo_ The 130p is a capable little scope, will show you plenty. It’s nice and portable too, so if you can get it somewhere just a little darker then you will see more.

Open clusters are a good target though, plenty to see and the brighter ones handle light pollution quite well.

[badhex]

12 hours ago, Stu said:

What are your skies like, and what scope do you have? Caroline’s Rose that Stephan suggested is wonderful but I think needs a decent sky to show its best.

I would agree with this - first saw Caroline's Rose about a month ago under Bortle 3/2 skies with a 73mm APO (ZS73) and it was really beautiful. Tried again under my Bortle 8/7 skies... pretty unimpressive  

The extra aperture of the 130 will certainly help though! Fingers crossed.

Edited October 22, 2021 by badhex

[_leo_]

31 minutes ago, badhex said:

I would agree with this - first saw Caroline's Rose about a month ago under Bortle 3/2 skies with a 73mm APO (ZS73) and it was really beautiful. Tried again under my Bortle 8/7 skies... pretty unimpressive  

The extra aperture of the 130 will certainly help though! Fingers crossed.

If I can learn where certain objects are and can go straight to them by practicing in my garden, hopefully I can then get to a dark site and see them again but looking even better!

Thats the plan anyway.

[Stu]

30 minutes ago, _leo_ said:

If I can learn where certain objects are and can go straight to them by practicing in my garden, hopefully I can then get to a dark site and see them again but looking even better!

Thats the plan anyway.

Learning where they are certainly helps, but sometimes at dark skies there are many more stars visible which can be confusing. Once you find them they will look much better though.

[Zermelo]

You may find it easier to start with clusters that are away from the milky way. I found some of the ones in Cassiopeia, for example, quite hard to detect against background stars, until I'd got my eye in.

[Merlin]

The Coathanger’s been mentioned as an open cluster, but isn’t it classified as an asterism?  There is an ancient and, apparently, understudied open cluster at one end of the Coathanger.

[badhex]

9 minutes ago, Merlin said:

The Coathanger’s been mentioned as an open cluster, but isn’t it classified as an asterism?  There is an ancient and, apparently, understudied open cluster at one end of the Coathanger.

I think you might be right - some years back it was reclassified as an asterism perhaps? Not really sure. Still beautiful either way!

[_leo_]

On 24/10/2021 at 22:26, Merlin said:

The Coathanger’s been mentioned as an open cluster, but isn’t it classified as an asterism?  There is an ancient and, apparently, understudied open cluster at one end of the Coathanger.

Do you know the name of this understudied open cluster? 

[Merlin]

The cluster has a NGC number, but I can’t remember it. Please let us know if you find it. The cluster was discribed as being very ancient and consisting mostly of red giants.

[Merlin]

Got it. The cluster is NGC 6802 and at Mag 8.8.

 

[Merlin]

34 minutes ago, Merlin said:

Got it. The cluster is NGC 6802 and at Mag 8.8.

 

After a further investigation the cluster isn’t very ancient, it’s middling. Also, red dwarfs dominate the cluster with only eight red giants.When I first learned about this open cluster, Gaia-ESO and other space telescopes didn’t exist, but now knowledge of the cluster has increased because of them.

Apparently, the cluster is regarded as important to astrophysicists these days for “calibration” purposes.

[Pixies]

Oh. NGC 6802 looks interesting (and not hard to locate)!

pic from Tom Wildoner

Edited October 26, 2021 by Pixies

[paulastro]

On 24/10/2021 at 22:26, Merlin said:

The Coathanger’s been mentioned as an open cluster, but isn’t it classified as an asterism?  There is an ancient and, apparently, understudied open cluster at one end of the Coathanger.

Yes, it's an asterism.

[Stu]

6 minutes ago, paulastro said:

Yes, it's an asterism.

Can an open cluster not be an asterism and vice versa? It seems confused as to whether all the stars in Cr 399 are in the same cluster or not.

[paulastro]

I thought an asterism by definition consists of stars that are not physically related, but I could be wrong Stu.

I can think of several Clusters which have bright stars within their boundaries which are not physically related, but just happen to be in the line of site. 

If I remember correctly, in NGC 457 (the Owl or ET cluster) the two bright stars which are the 'eyes' are not actually part of the cluster.

 

[Zermelo]

From Wikipedia :

"The stars within an asterism may be physically associated. For example, the stars of Collinder 399, which resembles a coathanger, are members of an open cluster,... "

[Stu]

9 minutes ago, paulastro said:

I thought an asterism by definition consists of stars that are not physically related, but I could be wrong Stu.

I can think of several Clusters which have bright stars within their boundaries which are not physically related, but just happen to be in the line of site. 

If I remember correctly, in NGC 457 (the Owl or ET cluster) the two bright stars which are the 'eyes' are not actually part of the cluster.

 

From what I can see, it is just any shape or pattern of stars which isn’t a constellation. Could be a smaller part such as the Plough, or could be parts of multiple constellations like the Summer Triangle. I think it can be both physically related stars and those that are not.