Rich Kron provided EdO the following information about this photo:
 

"The photo was taken in the summer of 1981.

Right to left:

Robert Loewenstein - Research Associate
Rich Kron - faculty
Bob Schommer - postdoc
Kyle Cudworth - faculty
Bill Morgan - emeritus faculty
Dan Peterson - grad student
Antonio Bianchini - visitor from Padua
Harold Henning - UofC undergraduate
Arnab Rai Choudhuri - grad student
Judith Lola (now Bausch) - librarian and ApJ editor
Al Harper - faculty
Bill Glaccum - grad student

The most interesting story relates to Bianchini.  He was Bob's guest, and
they had either just been to Wyoming to see Ron Canterna, or were on the way
there.  Anyway, the three of them were mutual friends, and very likely you
know more about that than I.  The Yerkes staff was charmed by Antonio's
visit, and I visited him at Padova on several occasions - all because of
Bob."