John Herschel discovered NGC 3105 = h3219 on 10 Apr 1834 and recorded "a small close clustering knot of stars 13-16 mag; oval; a great train of stars 12..13 mag on the S.p. side." HIs position is an exact match with this small cluster. Trumpler (Lick Obs Bul, Vol 14, No. 420) gives the diameter as 2.5' and the class as 2 2 p.

600/800mm - 24" (4/11/08 - Magellan Observatory, Australia): fairly bright compact cluster of just 2.5' diameter with 15 stars resolved at 200x. Using 350x the total increases to ~20 stars in a 2.5' region. A close unequal double is close west of center. A 25" pair of mag 11.5 stars lies 3' NE. Located 3' NW of a mag 9.6 star. Located 36' ESE of mag 3.5 Phi Velorum.

Notes by Steve Gottlieb