William Herschel discovered NGC 4156 = H II-642 = h1113, along with NGC 4151, on 17 Mar 1787 (sweep 714) and noted "pB, S." JH logged "vF; lE; vgbM."
300/350mm - 13.1" (3/17/86): faint, fairly small, slightly elongated E-W, possible faint stellar nucleus. Forms a pair with brighter NGC 4151 5.1' SW.
Notes by Steve Gottlieb