by Anthony Ayiomamitis
The open cluster NGC 884 depicted above along with NGC 869 which lies less than one-half of one degree away form the well-known "Double in Perseus". These clusters had been observed in antiquity based on the references by Hipparcus (130 BC). The cluster is estimated to be 3.2 million years old and to span several hundred million light-years in diameter. The brightest member stars include both older red supergiants and younger white hot stars. Both NGC 884 and NGC 869 are best observed using low magnifications (50-100x) and provide a stunning sight within the same field of view. The cluster lies at the midpoint between Perseus and Cassiopeia and is best observed during fall and winter when it is directly overhead around midnight.
Technical Details:
Date: Dec 07, 2010 (20:00 - 22:05 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 AO-8, SBIG CFW10, SBIG LRGB filters
Integrations: LRGB @ 30:30:30:30 using 3-/6-min subs, 1.16" per pixel, CCD @ -25.0° C
Further details: http://www.perseus.gr/Astro-DSO-NGC-0884.htm