Forty Globs in One

[coatesg]

I'll start by saying that I had all intentions of completing this as a colour image (and still want to!), but the weather and moon phase have scuppered my plans - just one cloudless, moonless night would be enough! The current colour data I have is insufficient, and has a tricky gradient that I can't remove at present. HA on this region would also be very interesting indeed to add later.

Anyhooo, bit of an alternative take on this subject, so here's an image in Lum only of a frequently imaged object, but perhaps not at this scale - this is NGC206 within M31.The image shows (fairly clearly) 40 known globular clusters in the field in total which are all associated with M31 - their positions were taken from the list of confirmed globulars out of the Bologna Catalogue (catalogue entry and magnitude in brackets is used for the labels in purple). Once marked up, it's actually quite possible in many cases to see the difference between a star and a globular, even at a distance of ~2.5MLy...

Note that the mottling in the star clouds within M31 itself is real and not an artifact - comparison to DSS images of the same region show the same patterns of lightness in the clouds. 

 

Image Details:

ST2000XM, 350mm double truss Newtonian (f4.53 - homemade, rebuilt from Orion SPX350), MPCC Mk I, Losmandy Titan.
Exposure: 85x3min (4h15min)
Processing: Pixinsight (Deconvolution, TGV denoise, Masked Stretch, Histogram Transforms, Local Histogram Equalization, Star reduction via Morphological Transform, very small application of dark structure enhancement script)
Field is approx 25'x19', pixel scale = 0.96". Presented at full scale for all pixel peepers ?

 

Annotated version:

 

 

[clarkpm4242]

Nice one!!

I had a go at visual observation of globular clusters in M31.  Used the Hodge Atlas.

Amazing what the eye and more so CCD can pick up 

Good luck

Paul