>Wagner mentioned ... NGC 6520
NGC 6520 is a nice cluster, but it is made even more appealing because it is
next to one of the darkest of the dark nebulae, B86, the Inkspot.
Very nearby this pair is a nearly unknown globular cluster, only discovered in
(I think) 1989, from plates. It has the designation Djorgovski 2 (E456-SC38). It
is easy to find by drawing a line from the center of the cluster through the
center of the dark nebula and extending that line about twice it's own length,
arriving at a small "keystone" of stars that look a lot like the Hercules
keystone, with one corner being a wide double star. Smack in the middle of that
keystone is Djorg 2. It is not too hard to see, even in a modest instrument.
This globular is reddened by interstellar matter a whopping 8 or 10 magnitudes,
meaning that it would rival the brightest of the bright globulars were it not
for the intervening dust!
See http://www.skylab.com.au/pmsa/ngc6520_b86.html which shows all 3
aforementioned objects pretty well. In my 25" telescope I can't go low enough in
power to get all 3 objects at the same time, but a telescope that is a little
smaller can do it easily enough.
I have a pretty good list of "double" objects, I'll dig it up and share it with
you.
\Paul Alsing
Received on Mon Apr 18 15:38:21 2005