|
Heart Nebula
The Heart Nebula (also known as the Running Dog Nebula, Sharpless 2-190) is an emission nebula, away from Earth and located in the Perseus Arm of the Galaxy in the constellation Cassiopeia. It was discovered by William Herschel on 3 November 1787. It displays glowing ionized hydrogen gas and darker dust lanes. The brightest part of the nebula (a knot at its western edge) is separately classified as NGC 896, because it was the first part of the nebula to be discovered. The nebula's intense red output and its morphology are driven by the radiation emanating from a small group of hot stars near the nebula's center. This open cluster of stars, known as Collinder 26, Melotte 15, or IC 1805, contains a few bright stars nearly 50 times the mass of the Sun, and many more dim stars that are only a fraction of the Solar mass. The Heart Nebula is also made up of ionised oxygen and sulfur gasses, which are responsible for the rich blue and orange colours seen in narrowband images. The neb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Head Nebula
The Fish Head Nebula, or the Northern Bear Nebula, is part of a large star forming system of gas and dust located along the Perseus spiral arm of the Milky Way. The nebula is located in the Constellation Cassiopeia, approximately 6,000 light-years from Earth and is adjacent to the much larger Heart Nebula. The brighter region of the nebula is designated NGC 896 and is the home to many young and large stars. These stars radiate high amounts of ultraviolet light. This UV radiation excites the surrounding gas and causes it to shine at a high brightness. This mapping is known as false color and is common with many of the Hubble Space Images. Gallery File:Heartandfish32hours.jpg, 32 hours of narrowband exposure File:Fish Head Nebula - Flickr - cfaobam.jpg, Fish Head Nebula (Photo: Carsten Frenzl) File:Fish Head Nebula IC1795 - Flickr - astrophotography andy.jpg, File:Heart nebula (53327408388).jpg, See also * Heart Nebula, another nebula nearby * Nebula * Astrophotography ... [...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] |
Sharpless Objects
Sharpless is a surname. Notable people with the surname include: *Bevan Sharpless (1904–1950), American solar system astronomer *Christopher Sharpless (born 1945), American 1988 Winter Olympics bobsledder *Isaac Sharpless (1848–1920), American educator *Josh Sharpless (born 1988), American baseball player *Karl Barry Sharpless (born 1941), American chemist and Nobel prize winner *Mattie R. Sharpless (born 1942), American diplomat *Nathan J. Sharpless (1823–1893), American politician from Pennsylvania *Norman Sharpless (born 1966), American oncologist and director of the National Cancer Institute *Stewart Sharpless (1926–2013), American galactic astronomer **Sharpless catalog, a 20th-century astronomical catalog with 313 items *Disappearance of Toni Sharpless (born 1979), American nurse who disappeared in 2009 Fictional characters *A character in Madama Butterfly See also *Sharpless asymmetric dihydroxylation, a chemical reaction *Sharpless epoxidation, a chemical reacti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H II Regions
H, or h, is the eighth letter of the Latin alphabet, used in the modern English alphabet, including the alphabets of other western European languages and others worldwide. Its name in English is ''aitch'' (pronounced , plural ''aitches''), or regionally ''haitch'' (pronounced , plural ''haitches'')''.''"H" ''Oxford English Dictionary,'' 2nd edition (1989); ''Merriam-Webster's Third New International Dictionary of the English Language, Unabridged'' (1993); "aitch" or "haitch", op. cit. Name English For most English speakers, the name for the letter is pronounced as and spelled "aitch" or occasionally "eitch". The pronunciation and the associated spelling "haitch" are often considered to be h-adding and are considered non-standard in England. It is, however, a feature of Hiberno-English, and occurs sporadically in various other dialects. The perceived name of the letter affects the choice of indefinite article before initialisms beginning with H: for example "an H-bomb" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC Objects
The ''New General Catalogue of Nebulae and Clusters of Stars'' (abbreviated NGC) is an astronomical catalogue of deep-sky objects compiled by John Louis Emil Dreyer in 1888. The NGC contains 7,840 objects, including 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 and Caroline Herschel, and John Herschel's '' General Catalogue of Nebulae and Clusters of Stars''. Objects south of the 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 the ''Revised New General Catalogue'' (RNGC) by Jack W. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of NGC Objects (1–1000)
This is a list of NGC objects 1–1000 from the New General Catalogue (NGC). The astronomical catalogue is composed mainly of star clusters, nebulae, and galaxies. Other objects in the catalogue can be found in the other subpages of the list of NGC objects. The constellation information in these tables is from ''The Complete New General Catalogue and Index Catalogue of Nebulae and Star Clusters by J. L. E. Dreyer'', which was accessed using the VizieR Service. Galaxy morphological types and objects that are members of the Small Magellanic Cloud are identified using the ''NASA/IPAC Extragalactic Database''. The other data of these tables are from the SIMBAD Astronomical Database unless otherwise stated. 1–100 101–200 201–300 301–400 401–500 501–600 601–700 701–800 801–900 901–1000 See also * Lists of astronomical objects This is a list of lists, grouped by type of astronomical object. Solar System * List of Sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soul Nebula
Westerhout 5 (Sharpless catalog, Sharpless 2-199, Lynds' Catalogue of Bright Nebulae, LBN 667, Soul Nebula) is an emission nebula located in Cassiopeia (constellation), Cassiopeia. Several small open clusters are embedded in the nebula: CR 34, 632, and 634 (in the head) and IC1848, IC 1848 (in the body). The object is more commonly called by the cluster designation IC 1848. Small emission nebula IC 1871 is present just left of the top of the head, and small emission nebulae 670 and 669 are just below the lower back area. The galaxies Maffei 1 and Maffei 2 are both nearby the nebula, although light extinction from the Milky Way makes them very hard to see. Once thought to be part of the Local Group, they are now known to belong to their own group- the IC 342/Maffei Group. This complex is the eastern neighbor of IC1805 (Heart Nebula) and the two are often mentioned together as the "Heart and Soul". Image:Heart and Soul nebulae.jpg, The Heart Nebula and Westerhout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Angular Diameter
The angular diameter, angular size, apparent diameter, or apparent size is an angular separation (in units of angle) describing how large a sphere or circle appears from a given point of view. In the vision sciences, it is called the ''visual angle'', and in optics, it is the ''angular aperture'' (of a lens (optics), lens). The angular diameter can alternatively be thought of as the angular displacement through which an eye or camera must rotate to look from one side of an apparent circle to the opposite side. A person can Angular resolution, resolve with their naked eyes diameters down to about 1 arcminute (approximately 0.017° or 0.0003 radians). This corresponds to 0.3 m at a 1 km distance, or to perceiving Venus as a disk under optimal conditions. Formulation The angular diameter of a circle whose plane is perpendicular to the displacement vector between the point of view and the center of said circle can be calculated using the formula :\delta = 2\arctan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degree (angle)
A degree (in full, a degree of arc, arc degree, or arcdegree), usually denoted by ° (the degree symbol), is a measurement of a plane (mathematics), plane angle in which one Turn (geometry), full rotation is 360 degrees. It is not an SI unit—the SI unit of angular measure is the radian—but it is mentioned in the SI Brochure, SI brochure as an Non-SI units mentioned in the SI, accepted unit. Because a full rotation equals 2 radians, one degree is equivalent to radians. History The original motivation for choosing the degree as a unit of rotations and angles is unknown. One theory states that it is related to the fact that 360 is approximately the number of days in a year. Ancient astronomers noticed that the sun, which follows through the ecliptic path over the course of the year, seems to advance in its path by approximately one degree each day. Some ancient calendars, such as the Iranian calendar, Persian calendar and the Babylonian calendar, used 360 days for a year. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with the chemical formula S8. Elemental sulfur is a bright yellow, crystalline solid at room temperature. Sulfur is the tenth most abundant element by mass in the universe and the fifth most common on Earth. Though sometimes found in pure, native form, sulfur on Earth usually occurs as sulfide and sulfate minerals. Being abundant in native form, sulfur was known in ancient times, being mentioned for its uses in ancient India, ancient Greece, China, and ancient Egypt. Historically and in literature sulfur is also called brimstone, which means "burning stone". Almost all elemental sulfur is produced as a byproduct of removing sulfur-containing contaminants from natural gas and petroleum.. Downloahere Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygen
Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), nonmetal, and a potent oxidizing agent that readily forms oxides with most elements as well as with other chemical compound, compounds. Oxygen is abundance of elements in Earth's crust, the most abundant element in Earth's crust, making up almost half of the Earth's crust in the form of various oxides such as water, carbon dioxide, iron oxides and silicates.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. It is abundance of chemical elements, the third-most abundant element in the universe after hydrogen and helium. At standard temperature and pressure, two oxygen atoms will chemical bond, bind covalent bond, covalently to form dioxygen, a colorless and odorless diatomic gas with the chemical formula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Mass
The solar mass () is a frequently used unit of mass in astronomy, equal to approximately . It is approximately equal to the mass of the Sun. It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. More precisely, the mass of the Sun is The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry of Earth. The first known estimate of the solar mass was by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
