Globular Cluster Messier 5 from the 2Mass Survey.

Globular Cluster M5 (also known as Messier Object 5 or NGC 5904) is a globular cluster in the constellation Serpens. It was discovered by Gottfried Kirch in 1702. Image File history File links Messier5. ... Image File history File links Messier5. ... 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 parsec (symbol pc) is a unit of length used in astronomy. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... A globular cluster is a spherical bundle of stars (star cluster) that orbits a galaxy as a satellite. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Serpens (the snake) is one of the 88 modern constellations, and was also one of the 48 listed by Ptolemy. ... Gottfried Kirch (Kirche, Kirkius) (December 18, 1639—July 25, 1710) was a German astronomer. ... Events March 8 - William III died; Princess Anne Stuart becomes Queen Anne of England, Scotland and Ireland. ...

Discovery and visibility

M5 is, under extremely good conditions, just visible to the naked eye as a faint "star" near the star 5 Serpentis. Binoculars or small telescopes will identify this cluster as non-stellar while larger telescopes will start to show individual stars, of which the brightest are of apparent magnitude 12.2. The Pleiades star cluster A star is a massive body of plasma in outer space that is currently producing or has produced energy through nuclear fusion. ... Binoculars A set of binoculars (from Latin, bi-, two-, and oculus, eye) is a hand-held tool used to magnify distant objects by passing the image through two adjacent series of lenses, and erecting prisms. ... 50 cm refracting telescope at Nice Observatory. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ...

M5 was discovered by the German astronomer Gottfried Kirch in 1702 when he was observing a comet. Charles Messier found it in 1764 and thought it a nebula without any stars associated with it. William Herschel resolved individual stars in the cluster in 1791, counting roughly 200 of them. Gottfried Kirch (Kirche, Kirkius) (December 18, 1639—July 25, 1710) was a German astronomer. ... Events March 8 - William III died; Princess Anne Stuart becomes Queen Anne of England, Scotland and Ireland. ... 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). ... William Herschel Sir Wilhelm Friedrich Herschel, FRS (November 15, 1738 – August 25, 1822) was a German-born British astronomer and composer who became famous for discovering the planet Uranus. ... 1791 (MDCCXCI) was a common year starting on Saturday (see link for calendar) of the Gregorian calendar (or a common year starting on Tuesday of the 11-day-slower Julian calendar). ...

M5 is not to be confused with the much fainter and more distant globular Palomar 5 which is situated nearby in the sky.

Scientific data

Spanning 165 light years across, M5 is one of the larger globular clusters known. The gravitational sphere of influence of M5, (ie. the volume of space where stars would be gravitationally bound to the cluster and not ripped away from it by the Milky Way's gravitational pull), has a radius of some 200 light years. A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Gravity is a force of attraction that acts between bodies that have mass. ...

At 13 billion years old it is also one of the older globulars associated with the Milky Way Galaxy. The distance of M5 is about 24,500 light-years away from Earth and the cluster contains more than 100,000 stars up to perhaps 500,000 according to some estimates. A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... The Milky Way (a translation of the Latin Via Lactea, in turn derived from the Greek Galaxia Kuklos; or simply the Galaxy) is a barred spiral galaxy in the Local Group, and has special significance to humanity as the location of the solar system, which is located near the Orion... Earth is the current Good Article Collaboration of the week! Please help to improve this article to the highest of standards. ...

Variable stars

Some 105 stars in M5 are known to be variable in brightness, some 97 of them are of the RR Lyrae type. RR Lyrae stars, sometimes referred to as "Cluster Variables", are somewhat similar to Cepheid type variables and as such can be used as a tool to measure distances in outer space since the relation between their luminosities and periods are well known. The brightest and most easily observed variable in M5 varies from magnitude 10.6 to 12.1 in a period of just under 26.5 days. A dwarf nova has also been observed in this cluster. Most stars are of almost constant luminosity. ... Hertzsprung-Russell diagram adapted from Powell. ... Cepheid in the Spiral Galaxy M100 A Cepheid variable or Cepheid is a member of a particular class of variable stars, notable for a fairly tight correlation between their period of variability and absolute luminosity. ... A day (symbol: d) is a unit of time equal to 24 hours. ...

External links

• M5,SEDS Messier pages
• Historic observations of M5
• Image of M5 by Waid Observatory