Open Cluster NGC 2331 in Gemini

Posted by ayiomamitis
on Sunday, November 29, 2009

by Anthony Ayiomamitis


As indicated by the image above, NGC 2331 in Gemini is an open cluster which is not very well detached from the background sky. It is comprised of 50 to 100 stars all of moderate brightness and spread across approximately 15 arc-minutes or half of the apparent diameter of the full moon. The cluster is not very well studied, for no estimates exist as to its physical distance or age. The cluster is best observed using low magnifications (50-100x) during winter when it is directly overhead and can be found to lie between Pollux (β-Gem, mag 1.22) and Mebsuta (ε-Gem, mag 2.99). NGC 2331 was discovered by William Herschel in 1785. Technical Details: Date: Nov 27, 2009 @ 03:05 - 05:10 UT+2 Location: Athens, Greece (38.2997° N, 23.7430° E) Equipment: AP 160 f/7.5 StarFire EDF, AP 1200GTO GEM, SBIG ST-10XME, SBIG CFW10, SBIG LRGB + IR-block Integrations: LRGB @ 30:30:30:30 (3-/6-min subs), Binning: 1x1, Image Scale: 1.17" per pixel, -25.0° C Futher Details:

To leave a comment you must be a member of our community.
Login to your account now, or register for an account to start participating.
No one has commented yet.
Join our Community!

Our community is FREE to join. To participate you must either login or register for an account.


Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. View our Privacy Policy.

Find us on Facebook