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Pegasus Dwarf Irregular Galaxy
The Pegasus Dwarf Irregular Galaxy (also known as Peg DIG or the Pegasus Dwarf) is a dwarf irregular galaxy in the direction of the constellation Pegasus. It was discovered by A. G. Wilson in the 1950s. The Pegasus Dwarf is a companion of the Andromeda Galaxy in the Local Group. General information In 1975 Tully & Fisher determined that it was part of the Local Group. The metallicity and the related distance estimate has been subject to discussions in the scientific literature, with varying results; however, recently, by use of the tip of the red-giant branch, a distance within 10% error was achieved in 2000 and then improved to 3% in 2005. In popular culture The science fiction television series ''Stargate Atlantis'' takes place in the "Pegasus galaxy" and has shown images of an irregular galaxy. However, the franchise has not explicitly stated if it is the Irregular, Spheroidal, or an entirely fictional location." The Return" (''Stargate Atlantis'') See also * Pegasus Dwa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digitized Sky Survey
The Digitized Sky Survey (DSS) is a digitized version of several 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 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 ESO/ SERC Southern Sky Atlas (known as the SERC-J, code "S") and the "quick" V-band (blue or V in the Johnson–Kron–Cousins system, Eastman Kodak IIa-D) SERC-J Equatorial Extension (SERC-QV, code "XV"), from the UK Schmidt Telescope at the Australian Siding Spring Observatory, wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a convenient short term for ''"all elements except hydrogen and helium"''. This word-use is distinct from the conventional chemical or physical definition of a metal as an electrically conducting solid. Stars and nebulae with relatively high abundances of heavier elements are called "metal-rich" in astrophysical terms, even though many of those elements are nonmetals in chemistry. The presence of heavier elements hails from stellar nucleosynthesis, where the majority of elements heavier than hydrogen and helium in the Universe (''metals'', hereafter) are formed in the cores of stars as they evolve. Over time, stellar winds and supernovae deposit the metals into the surrounding environment, enriching the interstellar medium and providing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andromeda Subgroup
The Andromeda Galaxy (M31) has satellite galaxies just like the Milky Way. Orbiting M31 are at least 13 dwarf galaxies: the brightest and largest is M110, which can be seen with a basic telescope. The second-brightest and closest one to M31 is M32. The other galaxies are fainter, and were mostly discovered only starting from the 1970s. On January 11, 2006, it was announced that Andromeda Galaxy's faint companion galaxies lie on or close to a single plane running through the Andromeda Galaxy's center. This unexpected distribution is not obviously understood in the context of current models for galaxy formation. The plane of satellite galaxies points toward a nearby group of galaxies (M81 Group), possibly tracing the large-scale distribution of dark matter. It is unknown whether the Triangulum Galaxy is a satellite of Andromeda. Table of known satellites Andromeda Galaxy's satellites are listed here by discovery (orbital distance is not known). Andromeda IV is not included in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarf Irregular Galaxies
An irregular galaxy is a galaxy that does not have a distinct regular shape, unlike a Spiral galaxy, spiral or an elliptical galaxy. Irregular galaxies do not fall into any of the regular classes of the Hubble sequence, and they are often chaotic in appearance, with neither a bulge (astronomy), nuclear bulge nor any trace of spiral arm structure. Collectively they are thought to make up about a quarter of all galaxies. Some irregular galaxies were once spiral or elliptical galaxies but were deformed by an uneven external gravitational force. Irregular galaxies may contain abundant amounts of gas and dust. This is not necessarily true for dwarf irregulars. Irregular galaxies are commonly small, about one tenth the mass of the Milky Way galaxy. Due to their small sizes, they are prone to environmental effects like crashing with large galaxies and intergalactic clouds. Types There are three major types of irregular galaxies: * An Irr-I galaxy (Irr I) is an irregular galaxy that f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus Galaxy (Stargate)
The mythology of the ''Stargate'' franchise is the historical backstory of the ''Stargate'' premise, which centers around xeno-mythology as experienced by humans during episodic contact. In the fictional universe of the franchise, the people of Earth have encountered numerous extraterrestrial races on their travels through the Stargate. In addition to a diversity of alien life, there is also an abundance of other humans, scattered across the cosmos by advanced aliens in the distant past. Some of the most significant species or beings in ''Stargate SG-1'' are the Goa'uld, the Asgard, and the Replicators. ''Stargate Atlantis'', set in the Pegasus galaxy, introduced the Wraith and the Asurans. One of the most influential species in ''Stargate'', the Ancients, have moved on to a higher plane of existence. For practical reasons of television productions, almost all of the alien and human cultures in the Stargate's fictional universe speak native English. Because of the time co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Return (Stargate Atlantis)
The third season of ''Stargate Atlantis'', an American-Canadian television series, began airing on July 21, 2006 on the US-American Sci Fi Channel. The third season concluded after 20 episodes on February 5, 2007 on the Canadian The Movie Network. The series was developed by Brad Wright and Robert C. Cooper, who also served as executive producers. Season three regular cast members include Joe Flanigan, Torri Higginson, Rachel Luttrell, Jason Momoa, Paul McGillion, and David Hewlett as Dr. Rodney McKay. Cast * Starring Joe Flanigan as Lt. Colonel John Sheppard * Torri Higginson as Dr. Elizabeth Weir * Rachel Luttrell as Teyla Emmagan * Jason Momoa as Ronon Dex * With Paul McGillion as Dr. Carson Beckett * And David Hewlett as Dr. Rodney McKay Episodes Episodes in bold are continuous episodes, where the story spans over 2 or more episodes. Production * Richard Kind, who played Lucius Lavin in "Irresistible" and "Irresponsible", also played a minor role as Gary Meyers in the or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pegasus Dwarf Spheroidal Galaxy
The Pegasus Dwarf Spheroidal (also known as ''Andromeda VI'' or ''Peg dSph'' for short) is a dwarf spheroidal galaxy about 2.7 million light-years away in the constellation Pegasus. The Pegasus Dwarf is a member of the Local Group and a satellite galaxy of the Andromeda Galaxy (M31). General information The Pegasus Dwarf Spheroidal is a galaxy with mainly metal-poor stellar populations. Its metallicity is e/H≃ −1.3. It is located at the right ascension 23h51m46.30s and declination +24d34m57.0s in the equatorial coordinate system (epoch J2000.0), and in a distance of 820 ± 20 kpc from Earth and a distance of 294 ± 8 kpc from the Andromeda Galaxy. The galaxy was discovered in 1999 by various authors on the Second Palomar Observatory Sky Survey (POSS II) films. See also * List of Andromeda's satellite galaxies * Pegasus Dwarf Irregular Galaxy (Peg DIG) * Pegasus galaxy, the Stargate Atlantis ''Stargate Atlantis'' (usually stylized in all caps and often abbrev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stargate Atlantis
''Stargate Atlantis'' (usually stylized in all caps and often abbreviated ''SGA'') is an adventure and military science fiction television series and part of MGM's ''Stargate'' franchise. The show was created by Brad Wright and Robert C. Cooper as a spin-off series of ''Stargate SG-1'', which was created by Wright and Jonathan Glassner and was itself based on the feature film '' Stargate'' (1994). All five seasons of ''Stargate Atlantis'' were broadcast by the Sci-Fi Channel in the United States and The Movie Network in Canada. The show premiered on July 16, 2004; its final episode aired on January 9, 2009. The series was filmed in and around Vancouver, British Columbia, Canada. The story of ''Stargate Atlantis'' follows the events of ''Stargate SG-1s seventh season finale episode " Lost City" and eighth season premiere episode " New Order", in which the cast of that series discovered an Antarctic outpost created by the alien race known as the Ancients. In the pilot episode " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Science Fiction
Science fiction (sometimes shortened to Sci-Fi or SF) is a genre of speculative fiction which typically deals with imaginative and futuristic concepts such as advanced science and technology, space exploration, time travel, parallel universes, extraterrestrial life, sentient artificial intelligence, cybernetics, certain forms of immortality (like mind uploading), and the singularity. Science fiction predicted several existing inventions, such as the atomic bomb, robots, and borazon, whose names entirely match their fictional predecessors. In addition, science fiction might serve as an outlet to facilitate future scientific and technological innovations. Science fiction can trace its roots to ancient mythology. It is also related to fantasy, horror, and superhero fiction and contains many subgenres. Its exact definition has long been disputed among authors, critics, scholars, and readers. Science fiction, in literature, film, television, and other media, has beco ... [...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 covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. 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 volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tip Of The Red-giant Branch
Tip of the red-giant branch (TRGB) is a primary distance indicator used in astronomy. It uses the luminosity of the brightest red-giant-branch stars in a galaxy as a standard candle to gauge the distance to that galaxy. It has been used in conjunction with observations from the Hubble Space Telescope to determine the relative motions of the Local Cluster of galaxies within the Local Supercluster. Ground-based, 8-meter-class telescopes like the VLT are also able to measure the TRGB distance within reasonable observation times in the local universe. Method The Hertzsprung–Russell diagram (HR diagram) is a plot of stellar luminosity versus surface temperature for a population of stars. During the core hydrogen burning phase of a Sun-like star's lifetime, it will appear on the HR diagram at a position along a diagonal band called the main sequence. When the hydrogen at the core is exhausted, energy will continue to be generated by hydrogen fusion in a shell around the core. The ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
