Messier 3
Encyclopedia
Messier 3 is a globular cluster
in the constellation
Canes Venatici
. It was discovered by Charles Messier
in 1764, and resolved into stars by William Herschel
around 1784. 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 33,900 light-year
s away from Earth
. M3 has an apparent magnitude
of 6.2, making it a difficult naked eye
target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It is estimated to be 8 billion years old. It is pretty difficult to spot this object in an amateur telescope without GoTo
as it has no nearby pointer stars; though it is almost exactly halfway between and on a line connecting Cor Caroli
with Arcturus.
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
Canes Venatici
Canes Venatici
Canes Venatici is one of the 88 official modern constellations. It is a small northern constellation that was created by Johannes Hevelius in the 17th century. Its name is Latin for "hunting dogs", and the constellation is often depicted in illustrations as representing the dogs of Boötes the...
. It was discovered by Charles Messier
Charles Messier
Charles Messier was a French astronomer most notable for publishing an astronomical catalogue consisting of deep sky objects such as nebulae and star clusters that came to be known as the 110 "Messier objects"...
in 1764, and resolved into stars by William Herschel
William Herschel
Sir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
around 1784. 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 33,900 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away from Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. M3 has an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of 6.2, making it a difficult naked eye
Naked eye
The naked eye is a figure of speech referring to human visual perception unaided by a magnifying or light-collecting optical device, such as a telescope or microscope. Vision corrected to normal acuity using corrective lenses is considered "naked"...
target even with dark conditions. With a moderate-sized telescope, the cluster is fully defined. It is estimated to be 8 billion years old. It is pretty difficult to spot this object in an amateur telescope without GoTo
GoTo (telescopes)
In amateur astronomy, "GoTo" refers to a type of telescope mount and related software which can automatically point a telescope to astronomical objects that the user selects...
as it has no nearby pointer stars; though it is almost exactly halfway between and on a line connecting Cor Caroli
Cor Caroli
Cor Caroli is the brightest star in the northern constellation Canes Venatici...
with Arcturus.