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NGC 2281
NGC 2281, also known as the Broken Heart Cluster, is an open cluster of stars in the northern constellation of Auriga. It was discovered by English astronomer William Herschel on March 4, 1788, and described as a, "cluster of coarsely scattered pretty rightstars, pretty rich". The Trumpler class for NGC 2281 is I3p, indicating a poor (p) but compact (I) grouping with a wide range of brightness (3). It is located at a distance of approximately from the Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ... and is 630–661 million years old. References External links * Image NGC 2281NGC 2281* NGC 2281 2281 Open clusters {{star-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a celestial body, as they are subject to perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auriga (constellation)
Auriga is a constellation in the northern celestial hemisphere. It is one of the List of constellations, 88 modern constellations; it was among the 48 constellations listed by the 2nd-century astronomer Ptolemy. Its name is Latin for '(the) charioteer', associating it with various mythological beings, including Erichthonius of Athens, Erichthonius and Myrtilus. Auriga is most prominent during winter evenings in the northern Hemisphere, as are five other constellations that have stars in the Winter Hexagon asterism (astronomy), asterism. Because of its northern declination, Auriga is only visible in its entirety as far south as −34°; for observers farther south it lies partially or fully below the horizon. A large constellation, with an area of 657 square degrees, it is half the size of the largest, Hydra (constellation), Hydra. Its brightest star, Capella (star), Capella, is an unusual Star system, multiple star system among the brightest stars in the night sky. Beta Aurigae ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collinder Catalogue
The Collinder catalogue is a catalogue of 471 open clusters compiled by Swedish astronomer Per Collinder. It was published in 1931 as an appendix to Collinder's paper ''On structural properties of open galactic clusters and their spatial distribution''. The catalogue contains 452 open clusters, 11 globular clusters, 6 Asterism (astronomy), asterisms, 1 Stellar kinematics#Moving groups, stellar moving group, and 1 Stellar kinematics#Stellar associations, stellar association. Catalogue objects are denoted by ''Collinder'', e.g. "Collinder 399". Dated prefixes include as ''Col + catalogue number'', or ''Cr + catalogue number'', e.g. "Cr 399". Collinder objects Notes Errors There are some errors in Collinder's list or references to it. For example:Archinal, B. A., and S. J. Hynes. 2003. ''Star Clusters'', Richmond, VA: Willmann-Bell * Cr 21, NGC 956, 27, NGC 1746, 57, NGC 6738, 396, Collinder 399, 399, and Messier 73, 426 are asterism (astronomy), asterisms. * Cr 32, 33, and 34 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philibert Jacques Melotte
Philibert Jacques Melotte (29 January 1880 – 30 March 1961) was a British astronomer whose parents emigrated from Belgium. In 1908 he discovered a natural satellite, moon of Jupiter, today known as Pasiphaë (moon), Pasiphaë. It was simply designated "Jupiter VIII" and was not given its present name until 1975. The outer main-belt asteroid 676 Melitta, the only asteroid he discovered, is named after the Attic Greek, Attic form of the Greek language, Greek ''Melissa'', the bee, but its resemblance to the discoverer's name is not fortuitous. The conspicuous star cluster in the Coma Berenices constellation is commonly designated Mel 111 since it appeared in Melotte catalogue, Melotte's 1915 catalogue of star clusters,Melotte, P. J"A Catalogue of Star Clusters shown on Franklin-Adams Chart Plates" ''MmRAS'', 1915 but not in Charles Messier's famous Messier object, catalogue of deep sky objects or in the New General Catalogue since it was not proved to be a true cluster until ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Cluster
A star cluster is a group of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars which are gravitationally bound; and open clusters, less tight groups of stars, generally containing fewer than a few hundred members. As they move through the galaxy, over time, open clusters become disrupted by the gravitational influence of giant molecular clouds, so that the clusters we observe are often young. Even though they are no longer gravitationally bound, they will continue to move in broadly the same direction through space and are then known as stellar associations, sometimes referred to as ''moving groups''. Globular clusters, with more members and more mass, remain intact for far longer and the globular clusters we observe are usually billions of years old. Star clusters visible to the naked eye include the Pleiades and Hyades (star cluster), Hyades open clusters, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OCL (astronomical Catalog) , football tournament
{{disambiguation ...
The initialism OCL can have several meanings, depending on context: *OCl−, the hypochlorite ion, in chemistry * Open Content License *Object Constraint Language * IBM Open Class Library * Operational Control Language of IBM mid-range computers *Overseas Containers Limited, former shipping company *OFC Champions League The OFC Men's Champions League is the premier men's club football competition in Oceania. It is organised by the OFC, Oceania's football governing body. Beginning as the Oceania Club Championship (1987–2006), it has been organised since 2007 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cluster
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and many more are thought to exist. Each one is loosely bound by mutual gravity, gravitational attraction and becomes disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a loss of cluster members through internal close encounters and a dispersion into the main body of the galaxy. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral galaxy, spiral and irregular galaxy, irregular galaxies, in which active star formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellations were likely defined in prehistory. People used them to relate stories of their beliefs, experiences, creation myth, creation, and mythology. Different cultures and countries invented their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. Naming constellations also helped astronomers and navigators identify stars more easily. Twelve (or thirteen) ancient constellations belong to the zodiac (straddling the ecliptic, which the Sun, Moon, and planets all traver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Herschel
Frederick William Herschel ( ; ; 15 November 1738 – 25 August 1822) was a German-British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel. Born in the Electorate of Hanover, William Herschel followed his father into the military band of Hanover, before immigrating to Kingdom of Great Britain, Britain in 1757 at the age of nineteen. Herschel constructed his first large telescope in 1774, after which he spent nine years carrying out sky surveys to investigate double stars. Herschel published catalogues of nebulae in 1802 (2,500 objects) and in 1820 (5,000 objects). The resolving power of the Herschel telescopes revealed that many objects called nebulae in the Messier object, Messier catalogue were actually clusters of stars. On 13 March 1781 while making observations he made note of a new object in the constellation of Gemini. This would, after several weeks of verification and consultation with other astrono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trumpler Class
An open cluster is a type of star cluster made of tens to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way galaxy, and many more are thought to exist. Each one is loosely bound by mutual gravitational attraction and becomes disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a loss of cluster members through internal close encounters and a dispersion into the main body of the galaxy. Open clusters generally survive for a few hundred million years, with the most massive ones surviving for a few billion years. In contrast, the more massive globular clusters of stars exert a stronger gravitational attraction on their members, and can survive for longer. Open clusters have been found only in spiral and irregular galaxies, in which active star formation is occurring. Young open clusters may b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal in astronomy, astrophysics and related fields. It publishes original research in two formats: papers (of any length) and letters (limited to five pages). MNRAS publishes more articles per year than any other astronomy journal. The learned society journal has been in continuous existence since 1827 and became online only in 2020. It operates as a partnership between the Royal Astronomical Society (RAS), who select and peer-review the contents, and Oxford University Press (OUP), who publish and market the journal. Despite its name, MNRAS is no longer monthly, nor does it carry the notices of the RAS. In 2024 MNRAS became a purely gold open access journal. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
