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SX Arietis Variables
SX Arietis variables are a class of variable stars. They are generally B-type main sequence stars of spectral types B0p to B9p— high-temperature analogues of Alpha2 Canum Venaticorum variables—and exhibit strong magnetic fields and intense He I and Si III spectral lines. They have brightness fluctuations of approximately 0.1 magnitudes with periods of about one day. The prototype of this class is 56 Arietis, which bears the variable star designation In astronomy, a variable star designation is a unique identifier given to variable stars. It uses a variation on the Bayer designation format, with an identifying label (as described below) preceding the Latin genitive of the name of the constell ... ''SX Arietis''. List The following list contains selected SX Arietis variable that are of interest to amateur or professional astronomy. Unless otherwise noted, the given magnitudes are in the V-band. Notes References Samus N.N., Durlevich O.V., et al. ''Combined G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
28 Cygni
28 Cygni is a binary star in the northern constellation of Cygnus. It is a faint blue-white hued star but visible to the naked eye with an apparent visual magnitude of 4.93. The distance to 28 Cyg, as estimated from its annual parallax shift of , is around 620 light years. It has an absolute magnitude of −2.56, which means that if the star were just away it would be brighter than Sirius, the brightest star in the night sky. This primary object is a B-type main-sequence star with a stellar classification of B2.5 V, per Lesh (1968). Slettebak (1982) found a class of B2 IV(e), which would suggest this is a more evolved subgiant star. It is a Be star, which means the spectrum displays emission lines due a disk of ejected gas in a Keplerian orbit around the star. The star displays short-term variability with two or more periods, and is classified as an SX Arietis variable by Samus et al. (2017). It is spinning rapidly with a projected rotational velocity ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eclipsing Binary
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 37017
HD 37017 is a binary star system in the equatorial constellation of Orion. It has the variable star designation V1046 Orionis; ''HD 37017'' is the identifier from the '' Henry Draper Catalogue''. The system is a challenge to view with the naked eye, being close to the lower limit of visibility with a combined apparent visual magnitude of 6.55. It is located at a distance of approximately 1,230 light years based on parallax, and is drifting further away with a radial velocity of +32 km/s. The system is part of star cluster NGC 1981 NGC 1981 (also known as OCL 525) is an open cluster which is located in the constellation Orion. It was discovered by John Herschel on 4 January 1827. Its apparent magnitude is 4.2 and its size is 28.00 arc minutes. It lies to the north of t .... The binary nature of this system was suggested by A. Blaauw and T. S. van Albada in 1963. It is a double-lined spectroscopic binary with an orbital period of 18.6556 days and an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HR 7355
HR 7355 is a star in the southern constellation of Sagittarius. It is faintly visible to the naked eye with an apparent visual magnitude of 6.03. The star is located at a distance of approximately 760 light years based on parallax measurements. The radial velocity of the star is poorly constrained, but it appears to be receding at the rate of +4 km/s. The stellar classification of HR 7355 is B2Vnn, indicating this is a B-type main-sequence star. The 'nn' notation indicates "nebulous" lines caused by rapid rotation. It is spinning on its axis with a period of 0.52 days. The projected rotational velocity is 310 km/s, for an estimated equatorial rotation rate of 358 km/s. This is 89% of the star's critical velocity, giving the star an equatorial bulge that is 20% larger than the polar radius. The star is subject to significant gravity darkening, with an effective temperature at the pole of 19,751 K compared to 15,740 K at the equator. In 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V929 Scorpii
V9 or V09 may refer to: Transportation * Fokker V.9, an experimental aircraft part of a series which led up to the low-production D.VI fighter * USS ''V-9'' or USS ''Cuttlefish'' (SS-171), a Cachalot-class submarine * Hughes XV-9, a 1960s American experimental helicopter * V9 Overstreet, a road in Milton Keynes, England * BAL Bashkirian Airlines (IATA code) * V9 Overstreet network of predominantly national speed limit, fully landscaped routes that form the top layer of the street hierarchy for both private and public transport in Milton Keynes, Buckinghamshire * V9 2937 Bashkirian Airlines Flight 2937, a Tupolev Tu-154 passenger jet, and DHL Flight 611, a Boeing 757 cargo jet, collided in mid-air over Überlingen, a southern German town on Lake Constance * Škoda-Kauba V9 Czechoslovakian aircraft Science and technology * Vivo V9, a smartphone by Vivo * ATC code V09 (diagnostic radiopharmaceuticals), a subgroup of the Anatomical Therapeutic Chemical Classification System * RAZ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V957 Scorpii
V957 Scorpii is a variable star in the constellation of Scorpius. It is a blue straggler in the open cluster Messier 7, a star that is unexpectedly hot compared to other members of the cluster. Spectrum V957 Scorpii shows a peculiar B5 or B6 spectrum. Its luminosity class has been given as main sequence (V), subgiant (IV), giant (III), and supergiant (Ib). From its position in the H-R diagram, it is actually thought to be a main sequence star. With a helium abundance 25 times lower than that of the sun, it is classified as helium-weak. It also has a low carbon abundance and a strong magnetic field. Messier 7 Messier 7 is a naked-eye open cluster. Except for one obvious orange giant star, its brightest members are mostly early A and late B main sequence stars and giants. Several of them are also chemically peculiar stars. However, two stars are hotter than the others and lie to the left of the isochrone for the cluster. These are the blue stragglers HD 16 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
3 Scorpii
3 (three) is a number, numeral and digit. It is the natural number following 2 and preceding 4, and is the smallest odd prime number and the only prime preceding a square number. It has religious or cultural significance in many societies. Evolution of the Arabic digit The use of three lines to denote the number 3 occurred in many writing systems, including some (like Roman and Chinese numerals) that are still in use. That was also the original representation of 3 in the Brahmic (Indian) numerical notation, its earliest forms aligned vertically. However, during the Gupta Empire the sign was modified by the addition of a curve on each line. The Nāgarī script rotated the lines clockwise, so they appeared horizontally, and ended each line with a short downward stroke on the right. In cursive script, the three strokes were eventually connected to form a glyph resembling a with an additional stroke at the bottom: ३. The Indian digits spread to the Caliphate in the 9th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 28843
HD 28843, also known as HR 1441 and DZ Eridani, is a star about 550 light years from the Earth, in the constellation Eridanus. It is a 5th magnitude star, so it will be faintly visible to the naked eye of an observer far from city lights. It is a variable star, whose brightness varies slightly from 5.70 to 5.84 during its 1.374 day rotation period. It is a member of the μ Tauri Association, a group of young stars within the larger Cassiopeia-Taurus Structure. In 1969 Mercedes Jaschek ''et al.'' determined that HD 28843 is a helium-weak star, based on its B-V color index being bluer (more negative) than would be expected for a star with its spectral type. In 1977, Robert Davis reported that the star has an overabundance of silicon. It is classified as a chemically peculiar star. Henning Jorgensen ''et al.'' reported that HD 28843 was a "suspected variable star" in 1971. The variability of the star was firmly established in 1977 by Holger Pedersen and Bjarne Thomse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 133880
HD 133880, also known as HR 5624 and HR Lupi, is a Bp star about 340 light years from the Earth, in the constellation Lupus. It is a 5th magnitude star, and will be faintly visible to the naked eye of an observer far from city lights. It is an SX Arietis variable star, varying from magnitude 5.76 to 5.81 over a period of 21.0594 hours. HD 133880 is a member of the Upper Centaurus–Lupus association. It is a young star, estimated to have completed only percent of its projected main sequence lifetime. It is one of the few stars known to produce coherent pulsed radio radiation via electron cyclotron maser emission. The spectrum of HD 133880 matches a B8 subgiant, but with unusually strong absorption lines of some metals, making it a member of the chemically peculiar Ap/Bp star class. For this particular star, silicon lines at are notably strong. Its rotation rate is unusually fast for a star of this type. In 1985, Christoffel Waelkens found that HD 133880 is a variabl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 21699
HD 21699, also known as HR 1063 and V396 Persei, is a star about 580 light years from the Earth, in the constellation Perseus. It is a 5th magnitude star, so it will be faintly visible to the naked eye of an observer far from city lights. It is a variable star, whose brightness varies slightly from 5.45 to 5.53 during its 2.4761 day rotation period. It has a remarkable dipole magnetic field which is displaced from the star's center by 0.4 stellar radii, the poles of which appear close to each other on the stellar surface. HD 21699 is a member of the Alpha Persei Cluster. Properties In 1967, Robert Garrison noted that the U-B color of HD 21699 is significantly bluer (more negative) than the spectral type assigned to it (B8 III) would suggest. Such a discrepancy suggests that the star is helium-weak. The star's helium-weak nature was confirmed by William Morgan ''et al.'' in 1971. HD 21699 also has an enhanced silicon abundance. John Winzer observed HD 21699 dur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
