Michael A. Stecker


Berkeley 17
The Berkeley-17 open or galactic star cluster is found about 3 degrees south of emission nebula IC 410 and
7 degrees west of SNR Simeis-147 in the constellation Auriga. It is about 13 arcminutes in diameter and is
very faint. Its age is estimated at 9 billion years making it by far the oldest open cluster yet seen. It is
unusual for a galactic cluster to achieve this age because of mixing and dispersing within the galactic disk.
Photographic Data: An Astro-Physics 155-mm f/7 EDF refractor and 35 mm camera were used with
hypersensitized Kodak Pro 400 PPF film. A single 40-minute exposure was made while centering at
RA 05 hrs, 20.5 min and Declination +30.5 degrees. The cluster size is 13' in diameter. The image
was processed in the computer.


Berkeley 17, wider field