NGC/IC Project Restoration Effort

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NGC7439

 

Basic Information


Location and Magnitude


Right Ascension: 22:58:9.9
Declination: +29:13:44
Constellation: PEG
Visual Magnitude: 14.0

Historic Information


Discoverer: Marth
Year of discovery: 1863
Discovery aperture: 48.0

Observational


Summary description: Long patch of F neby
Sub-type: SB0

Corwin's Notes

===== NGC 7439. Dave Riddle has pointed out that the NGC description of this nebula, found by Albert Marth in the summer of 1863, does not match the galaxy that the NGC number is usually attached to. Marth's description, copied faithfully into the NGC, reads in full, "Long patch of F nebulosity." The only detail beyond the discovery date given by Marth is the brief note "ver." ("verified"), which simply means that Marth saw the object on at least two nights. Interestingly, there is nothing at all at Marth's position. The usual recourse in cases like this is to search the area for the nearest non-stellar object. Here, the object is the galaxy UGC 12273 = MCG +05-54-021 = CGCG 496-027 = NPM1G +28.0471. This does not at all match Marth's description or RA (30 seconds off), though the Dec is within 1.5 arcmin, and it is certainly a galaxy that Marth could have seen -- many that he discovered are considerably fainter. MCG put a question mark on the NGC number, though CGCG and UGC accepted it without question marks. At one point or another, I penciled a question mark into my copy of CGCG (but not UGC until today, 19 July 2005), probably copied from MCG. Just today, I have also put question marks on the entries in the accurate position list. Other people searching unsuccessfully for the object were Curtis at Lick and Reinmuth at Heidelberg, both noted by Carlson in her 1940 ApJ list of NGC/IC corrections. The IC2 Note has a correction to the north polar distance by Bigourdan, but his object (seen only on the last of three nights that Bigourdan searched for NGC 7439) is a double star. Again, the appearance of the double does not match Marth's description, and there are other doubles in the area, too. I did a search around the area of Marth's position today, and around the areas of digit errors in his position (+- 10 arcmin, +- 1 degree, +- 1 hour, etc). I found no galaxies aside from NGC 7729 (41 min, 47 sec from Marth's position) that fit two of the three basic data bits (Dec and description). But given the large, non-digit separation in RA, I doubt very much that this is much more than a wild guess. So, I've put a question mark on the NGC number. I suspect it is the right object (right declination, RA just 30 seconds out), but the odd description is bothersome.

Steve's Notes

===== NGC 7439 17.5" (7/17/93): very faint, very small, round, 0.4' diameter, very weakly concentrated core, very faint stellar nucleus at moments. A mag 12.5 star is 2.5' WSW. Located 4.3' NW of mag 9.3 SAO 90908.