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Sky Survey
An astronomical survey is a general celestial cartography, map or astrophotography, image of a region of the sky (or of the whole sky) that lacks a specific observational target. Alternatively, an astronomical survey may comprise a set of images, spectra, or other observations of objects that share a common type or feature. Surveys are often restricted to one band of the electromagnetic spectrum due to instrumental limitations, although multiwavelength surveys can be made by using multiple detectors, each sensitive to a different bandwidth. Surveys have generally been performed as part of the production of an astronomical catalog. They may also search for transient astronomical events. They often use wide-field astrographs. Scientific value Sky surveys, unlike targeted observation of a specific object, allow astronomers to catalog celestial objects and perform statistical analyses on them without complex corrections for selection effects. In some cases, an astronomer interes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncertain Size-frequency Distribution Of Interstellar Visitors – not able to be relied on or lack of confidence
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Uncertain may refer to: * Uncertain, Texas, a town in the United States * ''Uncertain'' (album), 1991 album of The Cranberries * Uncertain, a music project of Florian-Ayala Fauna * '' Hoplodrina octogenaria'', a moth of Europe and Asia See also * Uncertainty Uncertainty or incertitude refers to situations involving imperfect or unknown information. It applies to predictions of future events, to physical measurements that are already made, or to the unknown, and is particularly relevant for decision ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2dF Galaxy Redshift Survey
In astronomy, the 2dF Galaxy Redshift Survey (Two-degree-Field Galaxy Redshift Survey), 2dF or 2dFGRS is a redshift survey conducted by the Australian Astronomical Observatory (AAO) with the 3.9m Anglo-Australian Telescope between 1997 and 11 April 2002. The data from this survey were made public on 30 June 2003. The survey determined the large-scale structure in two large slices of the Universe to a depth of around 2.5 billion light years (redshift ~ 0.2). It was the world's largest redshift survey between 1998 (overtaking Las Campanas Redshift Survey) and 2003 (overtaken by the Sloan Digital Sky Survey). Matthew Colless, Richard Ellis, Steve Maddox and John Peacock were in charge of the project. Team members Shaun Cole and John Peacock were awarded a share of the 2014 Shaw Prize in astronomy for results from the 2dFGRS. Description The 2dF survey covered an area of about 1500 square degrees, surveying regions in both the north and the south galactic poles. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitized Sky Survey
The Digitized Sky Survey (DSS) is a digital data, digitized version of several photography, photographic astronomical surveys of the night sky, produced by the Space Telescope Science Institute between 1983 and 2006. Versions and source material The term Digitized Sky Survey originally referred to the publication in 1994 of a digital version of an all-sky photographic atlas used to produce the first version of the Guide Star Catalog. For the northern sky, the National Geographic Society – Palomar Observatory Sky Survey E-band (red, named after the Eastman Kodak IIIa-E Photographic emulsion, emulsion used), provided almost all of the source data (plate code "XE" in the survey). For the southern sky, the J-band (blue, Eastman Kodak IIIa-J) of the European Southern Observatory, ESO/Science and Engineering Research Council, SERC Southern Sky Atlas (known as the SERC-J, code "S") and the "quick" V-band (blue or V in the UBV photometric system, Johnson–Kron–Cousins system, Eastm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CfA Redshift Survey
The Center for Astrophysics (CfA) Redshift Survey was the first attempt to map the large-scale structure of the universe. The first survey began in 1977 with the objective of calculating the velocities of the brighter galaxies in the nearby universe by measuring their redshifts at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts. The redshift is the relative increase in the wavelength emitted by a light source, in this case a galaxy, moving away from an observer from which its speed and then, using Hubble's law, its distance can be calculated. A 3-dimensional map of that part of the Universe could thus be produced. This initial data collection was completed by 1982. The second survey (CfA2) was started in 1985 by John Huchra and Margaret Geller and measured the redshifts of 18,000 bright galaxies in the Northern sky by 1995. Data from the second CfA survey showed that galaxies were not evenly distributed but clustered on the spherical surfaces of empty "vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Geographic Society – Palomar Observatory Sky Survey
The National Geographic Society – Palomar Observatory Sky Survey (NGS-POSS, or just POSS, also POSS I) was a major astronomical survey, that took almost 2,000 photographic plates of the night sky. It was conducted at Palomar Observatory, California, United States, and completed by the end of 1958. Observations The photographs were taken with the Samuel Oschin telescope at Palomar Observatory, and the astronomical survey was funded by a grant from the National Geographic Society to the California Institute of Technology. Among the primary minds behind the project were Edwin Hubble, Milton L. Humason, Walter Baade, Ira Sprague Bowen and Rudolph Minkowski. The first photographic plate was exposed on November 11, 1949. 99% of the plates were taken by June 20, 1956, but the final 1% was not completed until December 10, 1958. The survey utilized square photographic plates, covering about 6 ° of sky per side (approximately 36 square degrees per plate). Each region of the sky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pan-Andromeda Archaeological Survey
Pan-Andromeda Archaeological Survey (PAndAS) is a large-scale astronomical survey using the Canada-France-Hawaii Telescope. The survey is exploring the structure and content of the Andromeda Galaxy (M31) and its neighbour, the Triangulum Galaxy (M33). Clues to the formation of these galaxies may lie within the vast space being studied. PAndAS is searching for this history, hence the term " galactic archaeology". The project is headed by Dr. Alan McConnachie at the Herzberg Institute of Astrophysics (NRC-HIA), and involves over twenty five investigators from that institute, as well as from universities in Canada, France, the United States, the United Kingdom, Germany, and Australia. See also *Extragalactic astronomy *Observational cosmology Observational cosmology is the study of the structure, the evolution and the origin of the universe through observation, using instruments such as telescopes and cosmic ray detectors. Early observations The science of physical cosmology as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Catalina Sky Survey
Catalina Sky Survey (CSS; obs. code: 703) is an astronomical survey to discover comets and asteroids. It is conducted at the Steward Observatory's Catalina Station, located near Tucson, Arizona, in the United States. CSS focuses on the search for near-Earth objects, in particular on any potentially hazardous asteroid that may pose a threat of impact. Its counterpart in the southern hemisphere was the Siding Spring Survey (SSS), closed in 2013 due to loss of funding. CSS supersedes the photographic Bigelow Sky Survey. Mission The NEO Observations Program is a result of a United States 1998 congressional directive to NASA to begin a program to identify objects or larger to a confidence level of 90% or better. The Catalina Sky Survey, located at the Mount Lemmon Observatory in the Catalina Mountains north of Tucson, carries out searches for near-earth objects (NEOs), contributing to the congressionally-mandated goal. In addition to identifying impact risks, the projec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Draper Catalogue
The ''Henry Draper Catalogue'' (HD) is an astronomical star catalogue published between 1918 and 1924, giving spectroscopic classifications for 225,300 stars; it was later expanded by the ''Henry Draper Extension'' (HDE), published between 1925 and 1936, which gave classifications for 46,850 more stars, and by the ''Henry Draper Extension Charts'' (HDEC), published from 1937 to 1949 in the form of charts, which gave classifications for 86,933 more stars. In all, 359,083 stars were classified as of August 2017. The HD catalogue is named after Henry Draper, an amateur astronomer, and covers the entire sky almost completely down to an apparent photographic magnitude of about 9; the extensions added fainter stars in certain areas of the sky. The construction of the ''Henry Draper Catalogue'' was part of a pioneering effort to classify stellar spectra, and its catalogue numbers are commonly used as a way of identifying stars. History The origin of the ''Henry Draper Catalogue'' d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carte Du Ciel
The Carte du Ciel (; literally, 'Map of the Sky') and the Astrographic Catalogue (or Astrographic Chart) were two distinct but connected components of a massive international astronomical project, initiated in the late 19th century, to catalogue and map the positions of millions of stars as faint as 11th or 12th stellar magnitude, magnitude. Twenty observatories from around the world participated in exposing and measuring more than 22,000 (glass) photographic plates in an enormous observing programme extending over several decades. Despite, or because of, its vast scale, the project was only ever partially successful – the Carte du Ciel component was never completed, and for almost half a century the Astrographic Catalogue part was largely ignored. However, the appearance of the Hipparcos Catalogue in 1997 has led to an important development in the use of this historical plate material. Origins and goals A vast and unprecedented international star-mapping project was ini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bonner Durchmusterung
In astronomy, Durchmusterung or Bonner Durchmusterung (BD) is an astrometric star catalogue of the whole sky, published by the Bonn Observatory in Germany from 1859 to 1863, with an extension published in Bonn in 1886. The name comes from ('run-through examination'), a German word used for a systematic survey of objects or data. The term has sometimes been used for other astronomical surveys, including not only stars, but also the search for other celestial objects. Special tasks include celestial scanning in electromagnetic wavelengths shorter or longer than visible light waves. Original catalog The Bonner Durchmusterung (abbreviated BD), was initiated by Friedrich Argelander and using observations largely carried out by his assistants, which resulted in a catalogue of the positions and apparent magnitudes of 342,198 stars down to approximate apparent magnitude 9.5 and covering the sky from 90°N to 2°S declination. The catalogue, published in three parts, was accompanied by c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), extinction of the object's light caused by interstellar dust along the sightline, line of sight to the observer. Unless stated otherwise, the word ''magnitude'' in astronomy usually refers to a celestial object's apparent magnitude. The magnitude scale likely dates to before the ancient Ancient Greek astronomy#Astronomy in the Greco-Roman and Late Antique eras, Roman astronomer Ptolemy, Claudius Ptolemy, whose Star catalogue, star catalog popularized the system by listing stars from First-magnitude star, 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined to closely match this historical system by Norman Robert Pogson, Norman Pogson in 1856. The scale is reverse logarithmic scale, logarithmic: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
