William Herschel discovered NGC 5306 = H II-306 = h1671 = h3540 on 5 Mar 1785 (sweep 380) and recorded "F, vS, irreg, resolvable." From the Cape of Good Hope, JH called it "F; R; psbM; 20". NGC 5306 is the only member of HCG 67 seen by the Herschels.

400/500mm - 17.5" (5/11/96): moderately bright, fairly small, round, 1.0' diameter, well concentrated with a 20" bright core. A mag 13 star is 0.8' NW of center. NGC 5306 is the brightest member of HCG 67 with extremely faint MCG -01-35-013 = HCG 67B 3.4' NW. This edge-on is an extremely faint, moderately large streak, elongated 6:1 SSW-NNE with dimensions 2.0'x0.3'. Very low even surface brightness and requires averted vision to glimpse. A couple of times HCG 67D was highly suspected off the south edge (35" from center).

Notes by Steve Gottlieb