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Microscopium
Microscopium ("the Microscope") is a minor constellation in the southern celestial hemisphere, one of twelve created in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. The name is a Latinised form of the Greek word for microscope. Its stars are faint and hardly visible from most of the non-tropical Northern Hemisphere. The constellation's brightest star is Gamma Microscopii of apparent magnitude 4.68, a yellow giant 2.5 times the Sun's mass located 223 ± 8 light-years distant. It passed within 1.14 and 3.45 light-years of the Sun some 3.9 million years ago, possibly disturbing the outer Solar System. Two star systems— WASP-7 and HD 205739—have been determined to have planets, while two others—the young red dwarf star AU Microscopii and the sunlike HD 202628—have debris disks. AU Microscopii and the binary red dwarf system AT Microscopii are probably a wide triple system and members of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lacaille 8760
Lacaille 8760 (AX Microscopii) is a red dwarf star in the constellation Microscopium. It is one of the nearest stars to the Sun at about 12.9 light-years' distance, and the brightest M dwarf star in Earth's night sky, although it is generally too faint to be seen without a telescope. At an apparent magnitude of +6.7, it may only be visible to the unaided eye under exceptionally good viewing conditions, under dark skies. This star was originally listed in a 1763 catalog that was published posthumously by the French Abbé Nicolas Louis de Lacaille. He observed it in the southern sky while working from an observatory at the Cape of Good Hope. Number ''8760'' was assigned to this star in 1847 edition of Lacaille's catalogue of 9766 stars by Francis Baily.Francis Baily. ''A Catalogue of 9766 Stars'' (1847)Page 219/ref> In the past Lacaille 8760 has been classified anywhere from spectral class K7 down to M2. In 1979 the Irish astronomer Patrick Byrne discovered that it is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Microscopii
Gamma Microscopii (γ Microscopii, γ Mic) is the brightest star in the faint southern constellation of Microscopium. It has an apparent visual magnitude of 4.68, which is too dim to be viewed from city skies. The distance to this star has been determined using parallax measurements made with the Gaia telescope, which place it at . Based upon a stellar classification of G6 III, this is a G-type giant star. It is a core helium fusing star that is classified as a member of the red clump evolutionary branch, although the metallicity of this star—meaning the abundance of elements other than hydrogen and helium—is anomalously low for a member of this group. The effective temperature of the star's outer envelope is 5,050 K, giving it the yellow-hued glow typical of G-type stars. In the galactic coordinate system, this star has space velocity components of , V, W= 13.75, +3.47, . The peculiar velocity of this star, relative to its neighbors, is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WASP-7
WASP-7, also identified as HD 197286, is a type F star located about 520 light years away in the constellation Microscopium. This star is a little larger and about 28% more massive than the Sun and is also brighter and hotter. At magnitude 9 the star cannot be seen by the naked eye but is visible through a small telescope. Planetary system The SuperWASP project announced an extrasolar planet, WASP-7b, orbiting this star in 2008. The planet appears to be another hot Jupiter, a dense planet with Jupiter's mass orbiting very close to a hot star and thus emitting enough heat to ''shine''. See also * SuperWASP * List of extrasolar planets These are lists of exoplanets. Most of these were discovered by the Kepler space telescope. There are an additional 2,054 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 978 from its " Second Light" mission and ... References External links * Microscopium F-type main-sequence stars Pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BO Microscopii
BO Microscopii (BO Mic) is a star in the constellation Microscopium located about from the Sun. It has been dubbed "Speedy Mic" because of its very rapid rotation. The projected rotational velocity at the equator of this star is about , which, with an estimated inclination of 70° to the line of sight from the Earth, means it completes a rotation every . The photosphere of this star shows a high level of magnetic activity, with multiple star spots and prominences observed at the same time. As many as 25 prominences have been observed simultaneously, extending outward as far as 3.6 times the radius of the star. BO Mic is a flare star A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes. It is believed that the flares on flare stars are analogous to solar flares in that they are due to the magnetic energy stored in th ... that undergoes sudden increases in X-ray and ultraviolet emissions. These events can emit a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AU Microscopii
AU Microscopii (AU Mic) is a young small star located about away – about 8 times as far as the closest star after the Sun. The apparent visual magnitude of AU Microscopii is 8.73, which is too dim to be seen with the naked eye. It was given this designation because it is in the southern constellation Microscopium and is a variable star. Like β Pictoris, AU Microscopii has a circumstellar disk of dust known as a debris disk and at least two exoplanets. Stellar properties AU Mic is a young star at only 22 million years old; less than 1% of the age of the Sun. With a stellar classification of M1 Ve, it is red dwarf star with a physical radius of 75% that of the Sun. Despite being half the Sun's mass, it is radiating only 9% as much luminosity as the Sun. This energy is being emitted from the star's outer atmosphere at an effective temperature of 3,700 K, giving it the cool orange-red hued glow of an M-type star. AU Microscopii is a member of the β Pictor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AT Microscopii
AT Microscopii is a binary star system located at a distance of from the Sun in the constellation of Microscopium. Both members are flare stars, meaning they are red dwarf stars that undergo random eruptions that increase their brightness. This pair lies physically near the red dwarf star AU Microscopii, which may mean they form a wide triple star system. Observational history In 1926, Dutch-American astronomer Willem Jacob Luyten reported that the lines in the spectrum of this star underwent variation. A photographic plate taken on June 23, 1895, showed bright lines of hydrogen that were much weaker on a plate taken June 29, 1895. A photograph taken on July 1, 1903, showed no such lines. The net variation in brightness of the star was small, not exceeding 0.5 in magnitude. Luyten noted that the star has a large proper motion, changing its position by 0.43 seconds of arc between 1899 and 1923. By 1927, the object was found to be a pair of stars with an angular separat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 202628
HD 202628 is a single star in the southern constellation of Microscopium. It has an apparent visual magnitude of +6.7, which makes it too faint to be readily visible to the naked eye. The star is located at a distance of 77.7 light years from the Sun based on parallax, and it is drifting further away with a radial velocity of +12.1 km/s. The absolute magnitude of this star is 4.86. The stellar classification of HD 202628 is G1.5V, matching a yellow-hued G-type main-sequence star similar to the Sun. The chromospheric activity level and amount of X-ray emission is consistent with a star that is younger than the Sun. It is spinning with a projected rotational velocity of 2.6 km/s. The star has 107% of the mass of the Sun and 95% of the Sun's radius. The metallicity, or abundance of heavier elements, appears to be about the same as in the Sun. It is radiating 95% of the luminosity of the Sun from its photosphere at an effective temperature of 5,843 K. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piscis Austrinus
Piscis Austrinus is a constellation in the southern celestial hemisphere. The name is Latin for "the southern fish", in contrast with the larger constellation Pisces, which represents a pair of fish. Before the 20th century, it was also known as Piscis Notius. Piscis Austrinus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The stars of the modern constellation Grus once formed the "tail" of Piscis Austrinus. In 1597 (or 1598), Petrus Plancius carved out a separate constellation and named it after the crane. It is a faint constellation, containing only one star brighter than 4th magnitude: Fomalhaut, which is 1st magnitude and the 18th-brightest star in the night sky. Fomalhaut is surrounded by a circumstellar disk, and possibly hosts a planet. Other objects contained within the boundaries of the constellation include Lacaille 9352, the brightest red dwarf star in the night sky (though still too f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sagittarius (constellation)
Sagittarius is one of the constellations of the zodiac and is located in the Southern celestial hemisphere. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations. Its old astronomical symbol is (♐︎). Its name is Latin for "archer". Sagittarius is commonly represented as a centaur pulling back a bow. It lies between Scorpius and Ophiuchus to the west and Capricornus and Microscopium to the east. The center of the Milky Way lies in the westernmost part of Sagittarius (see Sagittarius A). Visualizations As seen from the northern hemisphere, the constellation's brighter stars form an easily recognizable asterism known as "the Teapot". The stars δ Sgr (Kaus Media), ε Sgr (Kaus Australis), ζ Sgr (Ascella), and φ Sgr form the body of the pot; λ Sgr (Kaus Borealis) is the point of the lid; γ2 Sgr (Alnasl) is the tip of the spout; and σ Sgr (Nunki) and τ Sgr the handle. These same sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telescopium
Telescopium is a minor constellation in the southern celestial hemisphere, one of twelve named in the 18th century by French astronomer Nicolas-Louis de Lacaille and one of several depicting scientific instruments. Its name is a Latinized form of the Greek word for telescope. Telescopium was later much reduced in size by Francis Baily and Benjamin Gould. The brightest star in the constellation is Alpha Telescopii, a blue-white subgiant with an apparent magnitude of 3.5, followed by the orange giant star Zeta Telescopii at magnitude 4.1. Eta and PZ Telescopii are two young star systems with debris disks and brown dwarf companions. Telescopium hosts two unusual stars with very little hydrogen that are likely to be the result of two merged white dwarfs: PV Telescopii, also known as HD 168476, is a hot blue extreme helium star, while RS Telescopii is an R Coronae Borealis variable. RR Telescopii is a cataclysmic variable that brightened as a nova to magnitude 6 in 1948. Tele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grus (constellation)
Grus (, or colloquially ) is a constellation in the southern sky. Its name is Latin for the crane, a type of bird. It is one of twelve constellations conceived by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Grus first appeared on a celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''Uranometria'' of 1603. French explorer and astronomer Nicolas-Louis de Lacaille gave Bayer designations to its stars in 1756, some of which had been previously considered part of the neighbouring constellation Piscis Austrinus. The constellations Grus, Pavo, Phoenix and Tucana are collectively known as the "Southern Birds". The constellation's brightest star, Alpha Gruis, is also known as Alnair and appears as a 1.7-magnitude blue-white star. Beta Gruis is a red giant variable star with a minimum magnitude of 2.3 and a maximum magnitude of 2.0. Six star systems have been foun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capricornus (constellation)
Capricornus is one of the constellations of the zodiac. Its name is Latin for "horned goat" or "goat horn" or "having horns like a goat's", and it is commonly represented in the form of a sea goat: a mythical creature that is half goat, half fish. Capricornus is one of the 88 modern constellations, and was also one of the 48 constellations listed by the 2nd century astronomer Claudius Ptolemy. Its old astronomical symbol is (♑︎). Under its modern boundaries it is bordered by Aquila, Sagittarius, Microscopium, Piscis Austrinus, and Aquarius. The constellation is located in an area of sky called the Sea or the Water, consisting of many water-related constellations such as Aquarius, Pisces and Eridanus. It is the smallest constellation in the zodiac. Notable features Stars Capricornus is a faint constellation, with only one star above magnitude 3; its alpha star has a magnitude of only 3.6. The brightest star in Capricornus is δ Capricorni, als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
