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NGC 1545
NGC 1545 is an open cluster in the constellation Perseus. It was discovered by William Herschel on December 28, 1790. It is located in the north-eastern part of the constellation, a few arcminutes east of the 4.5 magnitude star b Persei, near the equally large and bright NGC 1528 (m = 6.4), which is less than 1.5° towards the northwest. However, it is less dense and rich. The brightest star of the cluster is a K5 III giant star, with 7.1 magnitude, but its membership is questionable. One more 7.9 magnitude star is visible at the north edge of the cluster. References External links * 1545 Year 1545 ( MDXLV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. Events January–June * February 22 – A firman of the Ottoman Empire is issued for the dethronement of Radu ... Perseus (constellation) Open clusters {{star-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New General Catalogue
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalog, astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including galaxy, galaxies, star clusters and emission nebulae. Dreyer published two supplements to the NGC in 1895 and 1908, known as the ''Index Catalogues'' (abbreviated IC), describing a further 5,386 astronomical objects. Thousands of these objects are best known by their NGC or IC numbers, which remain in widespread use. The NGC expanded and consolidated the cataloguing work of William Herschel, William and Caroline Herschel, and John Herschel's ''General Catalogue of Nebulae and Clusters of Stars''. Objects south of the Celestial sphere, celestial equator are catalogued somewhat less thoroughly, but many were included based on observation by John Herschel or James Dunlop. The NGC contained multiple errors, but attempts to eliminate them were made by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1545
NGC 1545 is an open cluster in the constellation Perseus. It was discovered by William Herschel on December 28, 1790. It is located in the north-eastern part of the constellation, a few arcminutes east of the 4.5 magnitude star b Persei, near the equally large and bright NGC 1528 (m = 6.4), which is less than 1.5° towards the northwest. However, it is less dense and rich. The brightest star of the cluster is a K5 III giant star, with 7.1 magnitude, but its membership is questionable. One more 7.9 magnitude star is visible at the north edge of the cluster. References External links * 1545 Year 1545 ( MDXLV) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. Events January–June * February 22 – A firman of the Ottoman Empire is issued for the dethronement of Radu ... Perseus (constellation) Open clusters {{star-cluster-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cluster
An open cluster is a type of star cluster made of up 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. They are loosely bound by mutual gravity, gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a migration to the main body of the galaxy and a loss of cluster members through internal close encounters. 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 formation is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epoch (astronomy)
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 the po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perseus (constellation)
Perseus is a constellation in the northern sky, being named after the Greek mythological hero Perseus. It is one of the 48 ancient constellations listed by the 2nd-century astronomer Ptolemy, and among the 88 modern constellations defined by the International Astronomical Union (IAU). It is located near several other constellations named after ancient Greek legends surrounding Perseus, including Andromeda to the west and Cassiopeia to the north. Perseus is also bordered by Aries and Taurus to the south, Auriga to the east, Camelopardalis to the north, and Triangulum to the west. Some star atlases during the early 19th century also depicted Perseus holding the disembodied head of Medusa, whose asterism was named together as ''Perseus et Caput Medusae''; however, this never came into popular usage. The galactic plane of the Milky Way passes through Perseus, whose brightest star is the yellow-white supergiant Alpha Persei (also called Mirfak), which shines at magnitude 1.79. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Light Year
A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 (one million million, or billion in long scale). As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in a vacuum in one Julian year (365.25 days). Because it includes the time-measurement word "year", the term ''light-year'' is sometimes misinterpreted as a unit of time. The ''light-year'' is most often used when expressing distances to stars and other distances on a galactic scale, especially in non-specialist contexts and popular science publications. The unit most commonly used in professional astronomy is the parsec (symbol: pc, about 3.26 light-years) which derives from astrometry; it is the distance at which one astronomical unit subtends an angle of one second of arc. Defi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 au subtends an angle of one arcsecond ( of a degree). This corresponds to astronomical units, i.e. 1\, \mathrm = 1/\tan \left( \ \mathrm \right)\, \mathrm. The nearest star, Proxima Centauri, is about from the Sun. Most stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand. The word ''parsec'' is a portmanteau of "parallax of one second" and was coined by the British astronomer Herbert Hall Turner in 1913 to make calculations of astronomical distances from only raw observational data easy for astronomers. Partly for this reason, it is the unit preferred in astronomy and astrophysics, though the light-year remains prominent in popula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Collinder Catalogue
In astronomy, the Collinder catalogue is a catalogue of 471 open clusters 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''. 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". Vital statistics * The catalogue contains 471 objects: 452 open clusters, 11 globular clusters, 6 asterisms, 1 stellar moving group, and 1 stellar association. * Objects are spread out across the entire celestial sphere. * Cr 8 is the northernmost Collinder object, located at a declination of +85º in the constellation Camelopardalis. * Cr 411 is the southernmost Collinder object, located at a declination of -79º in the constellation Octans. Collinder objects which are also Messier objects The Collinder Catalogue contains 29 objects which are part of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Cluster
An open cluster is a type of star cluster made of up 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. They are loosely bound by mutual gravity, gravitational attraction and become disrupted by close encounters with other clusters and clouds of gas as they orbit the Galactic Center. This can result in a migration to the main body of the galaxy and a loss of cluster members through internal close encounters. 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 formation is o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
William Herschel
Frederick William Herschel (; german: Friedrich Wilhelm Herschel; 15 November 1738 – 25 August 1822) was a German-born British astronomer and composer. He frequently collaborated with his younger sister and fellow astronomer Caroline Herschel (1750–1848). Born in the Electorate of Hanover, William Herschel followed his father into the military band of Hanover, before emigrating to Great 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 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 consulta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B Persei
b Persei (also known as HD 26961) is a spectroscopic triple star in the constellation Perseus. Its apparent magnitude is 4.60, making it visible to the naked eye. It is about 320 light years away. In addition to the primary, an A-type giant, there is a smaller and cooler companion in a 1.53 day orbit, probably an F-class star around absolute magnitude 3.0, and a more distant companion (star C or Ac) in an orbit calculated to be 702 days long. The close binary pair forms a rotating ellipsoidal variable with a 1.53 day period. Star C forms an Algol-type variable system with the close binary, showing both primary eclipses (when star C passes in front of the inner pair) and secondary eclipses (when the inner pair passes in front of star C). Timings of the eclipses show a 705.4-day period. References {{DEFAULTSORT:B Persei Perseus (constellation) A-type giants Persei, b Persei, b BD+49 1150 026961 Persei, b 020070 1324 Year 1324 ( MCCCXXIV) was a leap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 1528
NGC 1528 is an open cluster in the constellation Perseus. It was discovered by William Herschel in 1790. It is located in the north-eastern part of the constellation, just under 3 degrees north of μ Persei. Less than 1.5° to the southeast is the open cluster NGC 1545 (m = 6.2). The NGC 1528 is clearly visible with 10x50 binoculars. 165 stars are recognised as members of NGC 1528, the brightest of which has apparent magnitude 8.7. See also * List of NGC objects (1001–2000) References External links * * SEDS {{DEFAULTSORT:NGC 1528 1528 __NOTOC__ Year 1528 ( MDXXVIII) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events January–June * January 12 – Gustav I of Sweden is crowned king of Sweden, having alread ... Perseus (constellation) Open clusters Discoveries by William Herschel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
