Photo of Messier 3 taken with a 24" telescope in Boulder, Colorado.

Globular Cluster M3 (also known as Messier Object 3 or NGC 5272) is a globular cluster in the Canes Venatici constellation. It was discovered by Charles Messier in 1764. This cluster is one of the largest and brightest, and is made up of around 500,000 stars. It is located at a distance of about 33900 light years away from Earth. M3 has an apparent magnitude of 6.2, making it visible to the naked eye in certain conditions. From a moderately-sized telescope, the cluster is fully defined. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... Messier Objects: M3 taken by rbruels From NASAs APOD site: This huge ball of stars predates our Sun. ... Messier Objects: M3 taken by rbruels From NASAs APOD site: This huge ball of stars predates our Sun. ... Pearl Street Mall in Downtown Boulder Boulder (40°1′N 105°16′W, Mountain Time Zone) is a city located in Boulder County, Colorado, United States. ... A globular cluster is a spherical bundle of stars (star cluster) that orbits a galaxy as a satellite. ... Canes Venatici (Latin for hunting dogs) is a small northern constellation that was introduced by Johannes Hevelius in the 17th century. ... Charles Messier Charles Messier (June 26, 1730 – (April 12, 1817) was a French astronomer who in 1774 published a catalogue of 45 deep sky objects such as nebulae and star clusters. ... 1764 was a leap year starting on Sunday (see link for calendar). ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Earth, also known as Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... A naked eye is a figure of speech, referring to human eyes unaided by enhancing equipment such as a telescope or binoculars. ...

External link

• SEDS Messier pages on M3