The O.A.S. Astrophotography Gallery

A place for members' images...

M3
M3 is one of the most outstanding globular clusters, containing an estimated half million stars. At a distance of about 33,900 light years, it is further away than the center of our Galaxy, the Milky Way, but still shines at magnitude 6.2, as its absolute magnitude is about -8.93, corresponding to a luminosity of about 300,000 times that of our sun. M3 is thus visible to the naked eye under very good conditions - and a superb object with the slightest optical aid. Its apparent diameter of 18.0 arc minutes corresponds to a linear extension of about 180 light years; Kenneth Glyn Jones mentions an estimate of even 20 arc minutes from deep photographic plates, corresponding to about 200 light years linear diameter. It appears somewhat smaller in amateur instruments, perhaps about 10 minutes of arc. But its tidal radius, beyond which member stars would be torn away by the tidal gravitational force of the Milky Way Galaxy, is even larger: About 38.19 minutes of arc. Thus, this cluster gravitationally dominates a shperical volume 760 light years in diameter.
Link-words: Messier Galaxy

M3

M3 is one of the most outstanding globular clusters, containing an estimated half million stars. At a distance of about 33,900 light years, it is further away than the center of our Galaxy, the Milky Way, but still shines at magnitude 6.2, as its absolute magnitude is about -8.93, corresponding to a luminosity of about 300,000 times that of our sun. M3 is thus visible to the naked eye under very good conditions - and a superb object with the slightest optical aid. Its apparent diameter of 18.0 arc minutes corresponds to a linear extension of about 180 light years; Kenneth Glyn Jones mentions an estimate of even 20 arc minutes from deep photographic plates, corresponding to about 200 light years linear diameter. It appears somewhat smaller in amateur instruments, perhaps about 10 minutes of arc. But its tidal radius, beyond which member stars would be torn away by the tidal gravitational force of the Milky Way Galaxy, is even larger: About 38.19 minutes of arc. Thus, this cluster gravitationally dominates a shperical volume 760 light years in diameter.

Rate this file (Current rating : 3 / 5 with 2 votes)
File information
Filename:CS_m3-20050417-OAS.jpg
Album name:CSuddell / Messier Objects
Rating (2 votes):33333
Link-words:Messier / Galaxy
Image date, time and location:17th April 2005
Telescope aperture and focal ratio:Meade LX90 @ F3.3, SAC8 40x1 second and 30x5 second images stacked using AIP4WIN.
Filesize:39 KiB
Date added:May 07, 2005
Dimensions:527 x 475 pixels
Displayed:227 times
URL:http://gallery.orpington-astronomy.org.uk/displayimage-154-_M3_.html
Favorites:Add to Favorites