Wilhelm Tempel discovered NGC 5431 = T VIII-10 on 25 Apr 1883 while observing the NGC 5416 group. In the narrative portion of list VI he mentions discovering two nebula about 5 or 6' away from each other and about 40s and 45s of RA following and several arc minutes south NGC 5416. NGC 5423 = UGC 8952 and NGC 5431 = CGCG 074-065 match this description. His declination in table VIII-10 is 4' too far north, although the position for NGC 5423 is accurate.

400/500mm - 17.5" (6/4/94): faint, round, 0.6' diameter, low surface brightness glow with no concentration. Located 4.5' WSW of a mag 10 star. Forms an equilateral triangle with NGC 5424 4.5' NW and NGC 5423 4.7' WSW. The double system NGC 5434 is 6.4' NE.

Notes by Steve Gottlieb