Messier Index/M10

right|200px|Messier 10 Courtesy Hunter Wilson M10 280px Messier 10 by Hubble Space Telescope; 3.5′ view NASA/STScI/WikiSky J2000 VII Ophiuchus 16 57 08.99SIMBAD Astronomical Database Results for NGC 6254 http://simbad.u-strasbg.fr/Simbad 2006-11-15 -04 05 57.6 14.3 kly 4.4 kpc 6.4 20′.0 41.6 ly distance × sin( diameter_angle / 2 ) = 41.6 ly. radius NGC 6254 Messier 10 Messier 10 or M10 (also designated NGC 6254) is a w:globular cluster in the w:constellation of w:Ophiuchus. The object was discovered by w:Charles Messier on w:May 29 w:1764, who cataloged it as number 10 in his list. He described it as a "w:nebula without stars", but later study revealed it as a globular cluster of thousands of stars. M10 has an apparent diameter of some 20 w:arcminutes, about two-thirds of the w:apparent diameter of the w:Moon. Viewed through medium-sized w:telescopes it appears about half that size (8' to 9'), as its bright core is only 35 light-years across. M10 has a spatial w:diameter of 83 w:light-years and is estimated to be 14,300 light-years away from Earth. Four w:variable stars have been discovered in this cluster. External links Messier 10, SEDS Messier pages Messier 10, Galactic Globular Clusters Database page References