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IC 4710
IC 4710 is a galaxy in southern constellation of Pavo (constellation), Pavo, roughly 34 million light-years away. Discovered on August 18, 1900 by astronomer DeLisle Stewart, this galaxy is composed of bright stars, with bright pockets — marking bursts of new star formation — scattered around its edges. It has a diameter of 36,000 light-years. IC 4710 is classified as a dwarf peculiar galaxy. As the name suggests, such galaxies are irregular and chaotic in appearance, lacking central bulges and spiral arms — they are distinctly different from spirals or ellipticals. It is thought that irregular galaxies may once have been spirals or ellipticals, but became distorted over time through external gravitational forces during interactions or mergers with other galaxies. Dwarf irregulars in particular are important to our overall understanding of galactic evolution, as they are thought to be similar to the first galaxies that formed in the Universe. IC 4710 lies in the southern co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hubble Space Telescope
The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls the spacecraft. Hubble features a mirror, and its five main instruments observe in the ultraviolet, visible, and near-infrared regions of the electromagnetic spectrum. Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of the most detaile ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, 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 Astronomical object, celestial body, as they are subject to Perturbation (astronomy), 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 Perihelion and aphelion, 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 bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HarperCollins
HarperCollins Publishers LLC is one of the Big Five English-language publishing companies, alongside Penguin Random House, Simon & Schuster, Hachette, and Macmillan. The company is headquartered in New York City and is a subsidiary of News Corp. The name is a combination of several publishing firm names: Harper & Row, an American publishing company acquired in 1987—whose own name was the result of an earlier merger of Harper & Brothers (founded in 1817) and Row, Peterson & Company—together with Scottish publishing company William Collins, Sons (founded in 1819), acquired in 1989. The worldwide CEO of HarperCollins is Brian Murray. HarperCollins has publishing groups in the United States, Canada, the United Kingdom, Australia, New Zealand, Brazil, India, and China. The company publishes many different imprints, both former independent publishing houses and new imprints. History Collins Harper Mergers and acquisitions Collins was bought by Rupert Murdoch's News Corpora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pavo (constellation)
Pavo is a constellation in the Southern Celestial Hemisphere, southern sky whose name is Latin for "peafowl, peacock". Pavo first appeared on a 35-cm (14 in) diameter celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''Uranometria'' of 1603, and was likely conceived by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. French explorer and astronomer Nicolas-Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Pavo, Grus (constellation), Grus, Phoenix (constellation), Phoenix and Tucana are collectively known as the "Southern Birds". The constellation's brightest member, Alpha Pavonis, is also known as Peacock and appears as a 1.91-Apparent magnitude, magnitude blue-white star, but is actually a spectroscopic binary. Delta Pavonis is a nearby Sun-like star some 19.9 light-years distant. Six of the star systems in Pavo have been found ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DeLisle Stewart
DeLisle Stewart (March 16, 1870 – February 2, 1941) was an American astronomer. In 1896 he became a staff member of Harvard College Observatory, and from 1898 to 1901 he worked at that observatory's station at Arequipa, Peru, where he took the photographic plates that William Henry Pickering used to discover Saturn's moon Phoebe. He discovered many new nebulas. Later he worked at Cincinnati Observatory until 1910, and later founded the Cincinnati Astronomical Society. He discovered the asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ... 475 Ocllo. References External links Brief obituary {{DEFAULTSORT:Stewart, Delisle 1870 births 1941 deaths Harvard University staff American astronomers Discoverers of asteroids Harvard College Observatory people ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milky Way
The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye. The term ''Milky Way'' is a translation of the Latin ', from the Greek ('), meaning "milky circle". From Earth, the Milky Way appears as a band because its disk-shaped structure is viewed from within. Galileo Galilei first resolved the band of light into individual stars with his telescope in 1610. Until the early 1920s, most astronomers thought that the Milky Way contained all the stars in the Universe. Following the 1920 Great Debate between the astronomers Harlow Shapley and Heber Curtis, observations by Edwin Hubble showed that the Milky Way is just one of many galaxies. The Milky Way is a barred spiral galaxy with an estimated D25 isophotal diameter of , but only about 1,000 light years thick at the spiral arms (more at the bulg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 6744
__NOTOC__ NGC 6744 (also known as Caldwell 101) is an intermediate spiral galaxy about 30 million light-years away in the constellation Pavo (Peacock). It is considered as a Milky Way mimic in the immediate vicinity, displaying flocculent (fluffy) arms and an elongated core. It also has at least one distorted companion galaxy (NGC 6744A) superficially similar to one of the Magellanic Clouds. It was discovered from Parramatta in Australia by Scottish astronomer James Dunlop on 30 June 1826. NGC 6744 lies within the Virgo Supercluster. See also * NGC 2336 - another spiral galaxy of similar size and shape * NGC 1232 * SPT0418-47 - a spiral galaxy of similar size and shape when the universe was 1.4 billion years old * UGC 12158 UGC 12158 or PGC 69533 is an Sb-type barred spiral galaxy located approximately away from Earth in the constellation of Pegasus. Its tight spiral disk spans approximately across, whose scale at heliocentric distance is about 36.9 kiloparsecs p ... R ... [...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] |
