William Herschel discovered NGC 3169 = H I-4 = h684, along with NGC 3166, on 19 Dec 1783 (early sweep 58). His summary description from 4 sweeps reads "cB, pL, cometic, mbM." He published a sketch in his 1811 paper (Fig. 22) as an illlustration of "nebulae that have a cometic appearance." John Herschel also made 4 observations, logging on 13 Feb 1826 (sweep 18): "B; R; gmbM; 60"; the foll of 2."

Édouard Stephan published accurate positions for NGC 3166 and 3169 from 18 Mar 1884 in his 13th list (#56 and 57), though he misidentified the galaxies as NGC 3165 and NGC 3166. R.J. Mitchell observed ths galaxy on 15 Mar 1855 with LdR's 72" and commented "sharp at sf edge [dust lane?] and fades of np, spreading out in that direction." The following January he also noted "perhaps vF neby beyond the well defined sf edge?"

300/350mm - 13" (4/16/83): bright, bright core.

400/500mm - 17.5" (3/23/85): bright, slightly elongated SW-NE, moderate concentration, pretty faint stellar nucleus. A mag 11 star is just off the east side, 1.6' from the center. Third of three with NGC 3166 7.8' WSW and NGC 3165 12' SW.

Notes by Steve Gottlieb