John Herschel discovered NGC 2793 = h572 on 6 Mar 1828 (sweep 128) and reported, "vF; R; has a double star 5' north; 1 sec preceding." His position and description matches the ring galaxy UGC 4893.

300/350mm - 13.1" (1/28/84): very faint, fairly small, round, 0.8' diameter, low even surface brightness. Located 53' W of Alpha Lyncis (V = 3.1).

900/1200mm - 48" (4/4/11): 375x and 488x provided a fascinating view of NGC 2793, a collisional ring galaxy. It appeared as a fairly faint, moderately large roundish glow, ~0.8' diameter, with a well defined edge. The rim was slightly brighter along the north side, giving a partial annular or ring-like appearance [the SDSS image resolves this brighter rim into a series of small HII knots or star-forming regions. The likely companion galaxy or intruder is visible along the east side of the rim as a fairly bright small glow of high surface brightness, elongated 2:1 N-S, ~15"x8", mottled appearance. The actual nucleus of the ring galaxy is perhaps situated at the north end of the disrupting galaxy. A 15" pair of mag 10 stars (h2491) lies 5' N. NGC 2793 is located 8' WNW of mag 9.7 PPM 74387.

LEDA 82356 = 2MASX J09164092+3426511, a background galaxy, is located just 1.7' NW. It appeared faint, small, round, ~15" diameter, low even surface brightness.

Notes by Steve Gottlieb