The cluster core radius is about 8 light years and tidal radius is about 43 light years. The cluster contains over 1,000 statistically confirmed members, although this figure excludes unresolved binary stars. It is dominated by young, hot blue stars, up to 14 of which can be seen with the naked eye depending on local observing conditions. The arrangement of the brightest stars is somewhat similar to Ursa Major andUrsa Minor. The total mass contained in the cluster is estimated to be about 800 solar masses.
The cluster contains many brown dwarfs, which are objects with less than about 8% of the Sun’s mass, not heavy enough for nuclear fusion reactions to start in their cores and become proper stars. They may constitute up to 25% of the total population of the cluster, although they contribute less than 2% of the total mass. Astronomers have made great efforts to find and analyse brown dwarfs in the Pleiades and other young clusters, because they are still relatively bright and observable, while brown dwarfs in older clusters have faded and are much more difficult to study.
Imaging telescopes or lenses: Takahashi TSA120
Imaging cameras: Canon 60Da
Mounts: Software Bisque Paramount MX
Guiding telescopes or lenses: Astro-Tech AT72ED
Guiding cameras: SBIG ST-i Mono
Software: Adobe Photoshop CS4, Deep Sky Stacker, Software Bisque The Sky X Pro
Accessories: Astro Tech ATFF
Dates: Nov. 24, 2013
Integration: 4.4 hours
Author: Chad Quandt
AstroPhotography of the day by SPONLI 08 June 2014