8 replies to this topic

[helpwanted]

Hello,

 

in Roger Clarke's book, Visual Astronomy of the Deep Sky, he has a few maps of star clusters with magnitudes listed for the stars, so you can check the limiting magnitude of your telescope. My question is are these charts thought to be reliable? if not, where is a good source of magnitudes for stars within clusters? The example i was using the other night was NGC 6910, a loose cluster that is easy to find your faintest star and compare to his charts. I'm hoping his data is correct!

 

thanks for your help,

 

David

 

[checcocpb]

Hello David,

 

that book is very interesting and informative I think they are correct, we can check with some planetarium software and see the correspondance. I think the magnitudes reported are in the V band of the spectrum. I'll check with Skysafari on my mac.

Cheers

[helpwanted]

I checked SkySafari, but my version is the Plus, so my limiting magnitude is 12, and that cluster has stars in the 14s & 15s. If SS also maps the stars within even some clusters, I'll upgrade my version!

[helpwanted]

I might be answering my own question... the book Star Clusters, by Hynes... it's on my shelf and i didn't think to check there till just now, I'll have to look this evening.  

[beggarly]

NGC 6910 on SYMBAD Astronomical Database:

 

http://simbad.u-stra...uery&CoordList=

[helpwanted]

thank you for that link, but that site is touch to figure out... at least while at work, i'll read up on it tonight

[semiosteve]

Skytools goes down to 20th magnitude. Here's a quick pdf for NGC 6910. You can tune parameters for magnitude, density, catalogs, etc.

 

 

Attached Files

•  NGC 6910.pdf   143.17KB   42 downloads

[Starman1]

They are reasonably accurate and appropriate for 8-10" apertures in dark skies.

Unfortunately, they don't go deep enough for 12.5" or larger in dark skies.

I use the following charts instead:

http://www.pk3.org/A...s_m057_maps.htm
http://www.cloudynig...agSequence1.jpg
http://www.flickr.co...ker/5954756749/

[helpwanted]

Thanks Don