Hi,

I have been reading about Stephan's quintet recently, and it seems
like there is some confusion as to which galaxies are part of it.
According to Wikipedia, the members of Stephan's quintet are: NGC
7317, NGC 7318a, NGC 7318b, NGC 7319 and NGC 7320c. NGC 7320 is not
listed as a member because of its small redshift, revealing that it is
a foreground galaxy. However, when this compact group was first
discovered by Edouard Stephan at the Marseilles observatory (which I
visited when I was a kid, Marseilles being my mother's hometown) in
1877, they surely had no idea of this fact, and NGC 7320 was probably
part of it, and not NGC 7320c (which Stephan might not even have seen
with his 16" scope?) Otherwise, the group would have been a sextet,
unless NGC 7318a and NGC 7318b were not resolved... Anyway, can
somebody shed some historic light on this? Also, it seems like
Stephan's quintet is also referred to as Hickson 92 nowadays. However,
Hickson's catalog of galaxies was published in 1982, so Hickson 92 and
Stephan's quintet may not contain exactly the same members.

I observed this compact galaxy group for the first time at GSSP with
my 12" scope, and it's a nice one indeed.

Cheers!
Julien