NGC 2509 & Ruprecht 46 -- Open Clusters in Puppis
NGC 2509, Ruprecht 46 and a Dead Car Battery
The constellation of the “Stern of the Ship Argo” (Puppis) is for the most part too far south from
my location in Central Maryland to view – but not all of it. There is a wide northern extension of
the constellation that rides the milky way north just to the east of Canis Major culminating in the
well-known Open Clusters of M46 and M47 (also do not forget the Open Cluster M93 south of
them). In addition, there are many additional Puppis Open Clusters along this stretch of the
Milky Way worth visiting. Two local Parks provided me far better southern views of the sky than
from my backyard, which I sketched eight of the best of the northern non-Messier Puppis Open
Clusters on the evenings of March 2nd and March 3rd (NGC 2421, 2479, 2482, 2489, 2509,
2527, 2567 and 2571).
NGC 2509 was a faint NW to SW elongated mist mixed with sprinkles of faint starlight. It
showed best at 164x magnification. Ruprecht 46 was very faint and had I not known what to
look for, and where to look, I would have missed it. At 164x I could only make out three stars
within a very faint blur of background light. Ruprecht 46 is a magnitude 9.1 Open Cluster
containing only about 15 stars.
Although, I used 164x for details within both clusters, the above drawing was done at 59x to
capture the surrounding star field and to get both clusters into the same field-of-view.
This was my last object for the night at Alpha Ridge Park. It was a very cold night, and it was
starting to wear on me. I packed up the telescope and was ready to drive home when my car
would not start. An additional hour was spent getting the car jump-started before I was able to