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UGC 2296

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#1 StanH


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Posted 17 April 2021 - 12:26 PM

As I am going back through my notes, I came across my entry for the galaxy UGC 2296.  It lies about 10' ENE of 40 Arietis.  It was attempted on the night of January 5, 2000 with the 17.5-inch.  My notes from the time show it was listed at magnitude 12.9 and as a suspected elliptical galaxy.  "4.8mm (380x):  For a galaxy so bright, I was uncertain of its detection. The problem is a star superimposed upon it.  At times I thought there was a glow, primarily east of the star, but I could not find an image to verify my observation.  It took about 30 minutes on the Internet to find out about this star.  Apparently it varies in brightness from about 12th magnitude to 15th magnitude though most of the time the fluctuations are slightly more than one-tenth of a magnitude.  At the time of observation it seemed about 12th magnitude, but after checking the magnitudes of several stars in the field I’d have to lower to 13th magnitude.  The article which identifies the star appears in a 1979 Astronomical Society of the Pacific publication.  Spectroscopic studies suggest it is an early class K main sequence star.  It is interesting that other publications list UGC 2296 as a high surface brightness galaxy and apparently are unaware this other study."


Thus far I have not come across any other observations of this galaxy as I looked online for more information.


The NED and PS1 actually plot the position as an extremely faint stellar object about 17" NE of the star though the NED notes refers to the star being superposed.  The NED does list a redshift of z = 0.03339.  One interesting note in the NED is a reference to supernova papers published in 2011 and 2017; however, I cannot find any mention of a supernova discovered in this galaxy.  As for the galaxy type it lists as a spiral with a question mark.  Some of the PS1 images suggest some sort of dark lane extending southwest, but is this real or an artifact as there are other dark lines in the images.


VSX lists the star as NSV 15585 with a range of 13.3-15B.    It also links to the abstract for the ASP paper.


If this is really a K main sequence star superposed it ought to show some proper motion.  Comparing the POSS1 Red to POSS2 does seem to suggest a slight movement to the east.  This seems to be confirmed from Gaia with proper motion of 53.297 mas in RA and -18.002 mas in declination.


Has anyone attempted this galaxy and was able to see the glow of it around the star?


VSX:  https://www.aavso.or...l.top&oid=54020


NED:  http://ned.ipac.calt...wmap=4&corr_z=1


PS1 image:  http://ps1images.sts...scale=99.500000



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#2 StanH


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Posted 17 April 2021 - 01:57 PM

Guess I shouldn't have taken a lunch break.  Had more on this galaxy from January 6, 2000.  "4.8mm (380x):  I am convinced the quoted magnitude includes the superimposed star.  The glow of the galaxy was extremely faint surrounding the 13th magnitude star.  It was round and about 20” across.  The galaxy lies about 9’ east-northeast of 40 Arietis (orange).  7.4mm + 2x Barlow (492x) and 4.8mm + 2x Barlow (760x):  A tiny spot seems to be detected about 2” east-northeast of the star.  Is this the actual core of the galaxy?"

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#3 Redbetter


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Posted 18 April 2021 - 03:26 AM

I haven't observed it, but the Pan Starrs image doesn't appear to be of much value for this one--probably too much glow from 40 Arietis washing out the extent of the galaxy.  The DSS2 image seems a better rendition, and more of a match to what you observed.  Probably ~15th B mag for the galaxy (vs. star) based on the glow surrounding the center/star.    The closest comparison of similar size and distance is might be IC 1832.  It is still a bit of a jog over to that one.

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#4 kt4hx


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Posted 18 April 2021 - 09:49 PM

Stan, here are my notes from 06 Jan 2018 using my 17.5 inch at our dark site. Hope that is helpful.


UGC 2296 (Aries, spiral galaxy, mag=13.1, size=0.851’x0.708’, SBr=12.29):


Just over 1° NNE of the cluster Do-Dz 1 and about 9.5' northeast of the mag 5.8 star 40 Arietis, I noticed the galaxy UGC 2296 in the atlas. Since it was nearby in a positional sense I decided to give it a try. Attempts at 84x and 108x came up empty. Then at 138x I had a very fleeting suspicion of something, but wasn’t overly certain. Pushing ahead to 172x, the sense that something was there was a bit stronger, but I still wasn’t convinced. Finally at 226x I confirmed that I was picking up a small, round and dim piece of galactic cotton. As I shifted between direct and averted vision, I seemed to be detecting what appeared to be a stellar core. However, checking on this later I am certain that this “stellar core” was nothing more than a mag 13.0 field star that lay a couple of arc seconds south of the center of the galaxy flashing into view occasionally.

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