Hi Scott & All,
First and foremost mate a lovely image! Well done. Beautiful colours and composition. But will the real NGC 2579 please stand up??
I tackled this field a several years ago for Sky & Tel (US). Many commercial planetarium sofware products (Megastar and ) plot NGC 2579 as an open cluster at RA 08 22 12 and Dec -36 24 00.
Reproduced below is a little of the text of the article:
Moving {2/3}northeast of q Puppis brings us to the field of NGC 2579. John Herschel discovered this open cluster in 1835 from his Cape of Good Hope observatory in South Africa. His observing notes from two different sweeps describe it as:
A double star or a star and a nebula, very close and involving the star. The field contains about 70 stars, of which 8 are 9th magnitude. I cannot be quite positive that the [nebula] extends beyond the large star, or that the small one is not a mere condensation of it. . . .
And:
A double star (h4083) involved in a pB nebula, which seems to belong to both stars; but of the two the smaller is more nebulous. . . .
Herschel’s notes plainly describe a small nebula in a rich Milky Way field. Despite that, NGC 2579 is plotted in many atlases and some planetarium programs as an open cluster. About 20 northwest from the symbol for NGC 2579, however, ESO 370-9 — a planetary nebula — is also plotted.
When I examined the field with my 12-inch reflector, I didn’t see any obvious cluster. I did glimpse, however, a small, conspicuous nebula of high surface brightness at the exact location for ESO 370-9. It appears generally round with a diffuse edge, and it lies northwest of a 10.5-magnitude star in a fairly rich field. It brightens somewhat to a spot just east of center, where there is a brightening or a faint star embedded. A smaller appended nebula surrounds the 10.5-magnitude star that’s just off the southeastern edge of the main mass. This second condensation is much fainter and lacks a “pip” (apart from the star). The nebula looks colorless and about 1 in diameter through a narrowband filter.
After more time at the eyepiece, I also noticed a very sparse grouping of about ten 9th- to 11th-magnitude stars spread over about 7 at the position marked by MegaStar for NGC 2579. This is about 20 southeast of the nebula. The grouping is very easily overlooked and looks little like a cluster to my eye — more like a chance grouping of some faint stars.
Only {1/4} east is another open cluster: Collinder 185. It displays about 15 stars between 10th and 11th magnitude spread over about 8 with no real concentration to the center. Most of its brighter members form an oval aligned north–south. The cluster is hardly conspicuous.
Herschel’s description of NGC 2579 best matches a combination of the small bright nebula designated ESO 370-9 along with the nearby star group that’s plotted as NGC 2579. Take a peek yourself and let me know your impressions.
Indeed NGC 2579 in this (professional astronomy) paper is also studied in considerable as an open cluster (very big link -- hope it doesn't break):
http://articles.adsabs.harvard.edu/c...;filetype=.pdf
And the paper casts doubt on whether it is a real open cluster. It does not really look much like one, at least in a 12" 'scope. It does however look somewhat like one in your image Scott.
However here, it is the nebula that is identified as NGC 2579:
http://cat.inist.fr/?aModele=afficheN&cpsidt=19054268
The position Herschel provides co-incides with a star-group in your photo Scott, on the edge of the image centre top. However, the description he gave clearly matches the compact HII nebula slightly below right in the image -- which is catalogued as ESO 370-9. In addition, he describes it as surrounding the pair HJ 4083 -- who's position is in the centre of the nebula.
So which one is the real NGC 2579?
Hard to tell really ... probably the nebula but as you've included both in the image you've got it covered really! BTW, Cr 185 is just off the top of the frame.
Best,
Les D