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W Ursae Majoris Variable
A W Ursae Majoris variable, also known as a low mass contact binary, is a type of eclipsing binary variable star. These stars are close binaries of spectral types F, G, or K that share a common envelope of material and are thus in contact with one another. They are termed contact binary, contact binaries because the two stars touch and transfer mass and energy through the connecting neck, although astronomer Robert E. Wilson argues that the term "overcontact" is more appropriate. The class is divided into two subclasses: A-type and W-type. A-type W UMa binaries are composed of two stars both hotter than the Sun, having stellar classification, spectral types A or F, and orbital period, periods of 0.4 to 0.8 day. The W-types have cooler spectral types of G or K and shorter periods of 0.22 to 0.4 day. The difference between the surface temperatures of the components is less than several hundred kelvins. A new subclass was introduced in 1978: B-type. The B-types have larger surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Star System - Contact Configuration Q=3
Binary may refer to: Science and technology Mathematics * Binary number, a representation of numbers using only two digits (0 and 1) * Binary function, a function that takes two arguments * Binary operation, a mathematical operation that takes two arguments * Binary relation, a relation involving two elements * Binary-coded decimal, a method for encoding for decimal digits in binary sequences * Finger binary, a system for counting in binary numbers on the fingers of human hands Computing * Binary code, the digital representation of text and data * Bit, or binary digit, the basic unit of information in computers * Binary file, composed of something other than human-readable text ** Executable, a type of binary file that contains machine code for the computer to execute * Binary tree, a computer tree data structure in which each node has at most two children Astronomy * Binary star, a star system with two stars in it * Binary planet, two planetary bodies of comparable mas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
W Ursae Majoris
W Ursae Majoris (W UMa) is the variable star designation for a binary star system in the northern constellation of Ursa Major. It has an apparent visual magnitude of about 7.9, which is too faint to be seen with the naked eye. However, it can be viewed with a small telescope. Parallax measurements place it at a distance of roughly 169 light years (52 parsecs) from Earth. In 1903, the luminosity of this system was found to vary by the German astronomers Gustav Müller (astronomer), Gustav Müller and Paul Friedrich Ferdinand Kempf, Paul Kempf. It has since become the prototype and wikt:eponym, eponym for a class of variable stars called W Ursae Majoris variables. This system consists of a pair of stars in a tight, circular orbit with a orbital period, period of 0.3336 days, or eight hours and 26 seconds. During every orbital cycle, each star eclipses the other, resulting in a decrease in magnitude. The maximum magnitude of the pair is 7.75 mag. During the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corona Australis
Corona Australis is a constellation in the Southern Celestial Hemisphere. Its Latin name means "southern crown", and it is the southern counterpart of Corona Borealis, the northern crown. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the 88 modern constellations. The Ancient Greeks saw Corona Australis as a wreath rather than a crown and associated it with Sagittarius (constellation), Sagittarius or Centaurus. Other cultures have likened the pattern to a turtle, ostrich nest, a tent, or even a hut belonging to a rock hyrax. Although fainter than its northern counterpart, the oval- or horseshoe-shaped pattern of its brighter stars renders it distinctive. Alpha Coronae Australis, Alpha and Beta Coronae Australis are the two brightest stars with an apparent magnitude of around 4.1. Epsilon Coronae Australis is the brightest example of a W Ursae Majoris variable in the southern sky. Lying alongside the Milky Way, Corona Australi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Coronae Australis
Epsilon Coronae Australis (ε CrA), is a star system located in the constellation Corona Australis. Varying in brightness between apparent magnitudes of 4.74 to 5 over 14 hours, it is the brightest W Ursae Majoris variable (low mass contact binary) in the night sky. Naming Nicolas Louis de Lacaille gave Epsilon Coronae Australis its Bayer designation. It is also known as HR 7152, and HD 175813. Properties Epsilon Coronae Australis is an F4V dwarf star with an effective temperature of 6000 Kelvin. It ranges between apparent magnitudes of 4.74 to 5 over 14 hours, an absolute magnitude of +2.45, and a mass of 1.1 solar masses. Epsilon Coronae Australis is a W Ursae Majoris variable A W Ursae Majoris variable, also known as a low mass contact binary, is a type of eclipsing binary variable star. These stars are close binaries of spectral types F, G, or K that share a common envelope of material and are thus in contact with one ..., indicating that it has a contact companion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WZ Cephei
WZ Cephei is an eclipsing binary star of W Ursae Majoris-type in the constellation of Cepheus, located 880 light years away from the Sun. The stars orbit around a common orbital barycenter every 0.41744 days (slightly over 10 hours). Timing analyses have revealed the possible presence of a third low-mass stellar companion in a wide orbit. Presence of a third body According to Zhu & Qian (2009) a third low-mass object of stellar nature could be responsible of orbital period variations observed for WZ Cep with a periodicity of roughly 32 years. Such a companion would yield a minimum mass of 0.17 Solar masses and be located 26.6 Astronomical Units (nearly the same orbital separation of Neptune in Solar System) from the eclipsing binary. The star could likely turn out a Proxima Centauri Proxima Centauri is a small, low-mass star located away from the Sun in the southern constellation of Centaurus. Its Latin name means the 'nearest tarof Centaurus'. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cepheus (constellation)
Cepheus is a constellation in the far northern sky, named after Cepheus, a king of Aethiopia in Greek mythology. It is one of the 48 constellations listed by the second century astronomer Ptolemy, and it remains one of the 88 constellations in the modern times. The constellation's brightest star is Alpha Cephei, with an apparent magnitude of 2.5. Delta Cephei is the prototype of an important class of star known as a Cepheid variable. RW Cephei, an orange hypergiant, together with the red supergiants Mu Cephei, MY Cephei, SW Cephei, VV Cephei, and V354 Cephei are among the largest stars known. In addition, Cepheus also has the hyperluminous quasar S5 0014+81, which hosts an ultramassive black hole in its core, reported at 40 billion solar masses, about 10,000 times more massive than the central black hole of the Milky Way, making this among the most massive black holes currently known. This paper does acknowledge the possibility of an optical illusion that would cause an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VW Cephei
VW Cephei (VW Cep) is an eclipsing contact binary of W Ursae Majoris-type located roughly at 90.6 light years from the Sun, whose two component stars share a common outer layer. Because the two components share their outer layers, as the components of W Ursae Majoris do, they have the same stellar classification, and are classified as yellow G-type main sequence dwarfs. The components take 0.2783 days (roughly 6.7 hours) to revolve around a common barycentre. Orbital period variations suggest the presence of one more additional perturbing objects of likely low-mass stellar nature. Unseen companion(s) Orbital period variations suggest the presence of one more perturbing unseen object around the eclipsing binary. Several publications have tried to set constrains to putative orbital period and minimum mass for unseen component. The most recent article proposes an orbital period of 29.8 years for a stellar object with roughly three fourths the Sun's mass and hig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boötes
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ' herdsman' or 'plowman' (literally, ' ox-driver'; from ''boûs'' 'cow'). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Boötis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. History and mythology In ancient Babylon, the stars of Boötes were known as SHU.PA. They were apparently depicted as the god Enlil, who was the leader of the Babylonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
44 Boötis
44 Boötis or i Boötis is a triple star system in the constellation Boötes. It is approximately 41.6 light years from Earth. 44 Boötis can be resolved into two stars, of 5th and 6th magnitudes respectively. They were separated by when the pair were confirmed in 1819, but were only by 2020 as the two orbit every 210 years. The primary component, 44 Boötis A, is a yellow-white stellar classification, G-type main sequence, main sequence dwarf with a mean apparent magnitude of +4.83. The companion component, 44 Boötis B, is a W Ursae Majoris variable spectroscopic binary. The variability of this star system was discovered by English astronomer William Herschel. The brightness of the eclipsing binary varies from magnitude +5.8 to +6.40 with a period of 6.43 hours. The two eclipsing components of the are close enough to allow their stellar envelopes to overlap, or at least nearly so. The 44 Boötis system is from Earth. It also may show signs of an infrared exce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antlia
Antlia (; from Ancient Greek ''ἀντλία'') is a constellation in the Southern Celestial Hemisphere. Its name means " pump" in Latin and Greek; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by Nicolas-Louis de Lacaille in the 18th century. Its non-specific (single-word) name, already in limited use, was preferred by John Herschel then welcomed by the astronomic community which officially accepted this. North of stars forming some of the sails of the ship Argo Navis (the constellation Vela), Antlia is completely visible from latitudes south of 49 degrees north. Antlia is a faint constellation; its brightest star is Alpha Antliae, an orange giant that is a suspected variable star, ranging between apparent magnitudes 4.22 and 4.29. S Antliae is an eclipsing binary star system, changing in brightness as one star passes in front of the other. Sharing a common envelope, the stars are so close they will one day merge to form a singl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
S Antliae
S Antliae is a W Ursae Majoris-type eclipsing binary star in Antlia. Characteristics S Antilia is classed as an A-type W Ursae Majoris variable, since the primary is hotter than the secondary and the drop in magnitude is caused by the latter passing in front of the former. S Antilia varies in apparent magnitude from 6.27 to 6.83 over a period of 15.6 hours. The system shines with a combined spectrum of A9V. The system's orbital period is 0.648 days. The stars' centres are an average of 3.31 times the sun's radius apart, which places their surfaces just 3.4 times the sun's radius apart. Thus, the two stars will eventually merge to form a single fast-spinning star. Calculating the properties of the component stars from the orbital period indicates that the primary star has a mass 0.79 times and a diameter 1.46 times that of the Sun, and the secondary has a mass 0.47 times and a diameter 1.13 times that of the Sun. The primary has a surface temperature of 7800 K, while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
