|
Tau Andromedae
Tau Andromedae, Latinized from τ Andromedae, is the Bayer designation for a single star in the northern constellation of Andromeda. It has an apparent visual magnitude of +4.94, which is bright enough to be viewed from dark suburban skies. From parallax measurements made during the Gaia mission, the distance to this star can be estimated as roughly from Earth. The brightness of this star is diminished by 0.24 in magnitude due to extinction caused by intervening gas and dust. It is drifting closer to the Sun with a radial velocity of −14 km/s. The spectrum of this star matches a stellar classification of B5 III, with the luminosity class of III indicating that this is a giant star. It is radiating about 851 times the luminosity of the Sun from its photosphere at an effective temperature of 12,670 K. The star is an estimated 217 million years old and is spinning with a high projected rotational velocity of ~74 km/s. Naming In Chinese, (), m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Andromedae
T Andromedae (T And) is a variable star of the Mira variable, Mira type in the constellation Andromeda (constellation), Andromeda. Like all the stars of this kind, T And is a cool asymptotic giant branch star of spectral type M4e-M7.5e. Its brightness varies periodically, completing a cycle in 281 days. The peak luminosity, however, is different every variability cycle, but can reach a peak apparent magnitude, magnitude mv=7.70.General Catalogue of Variable Stars, ''s.v.'' T. And. Thomas David Anderson discovered that T Andromedae is a variable star, in 1894. The next year, Edward Charles Pickering examined archival Photographic_plate#Astronomy, photographic plates to derive a light curve for the star, and calculated a period of 281 days. Measurements of the angular size variations of T And made with the Palomar Testbed Interferometer show no clear correlation with the star's brightness variations. References External linksImage Andromeda (constellation) Henry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known. When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less than that of a black body), the actual temperature of the body will be higher than the effective temperature. The net emissivity may be low due to surface or atmospheric properties, including greenhouse effect. Star The effective temperature of a star is the temperature of a black body with the same luminosity per ''surface area'' () as the star and is defined according to the Stefan–Boltzmann law . Notice that the total (bolometric) luminosity of a star is then , where is the stellar radius. The definition of the stellar radius is obviously not straightf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Trianguli
Delta Trianguli, Latinized from Delta Tri, is a spectroscopic binary star system approximately away in the constellation of Triangulum. The primary star is a yellow dwarf, while the secondary star is thought to be an orange dwarf. It has an apparent magnitude of +4.87 and forms an optical (line-of-sight) triple with Gamma Trianguli and 7 Trianguli. Stellar components Delta Trianguli A is a main sequence star with a stellar classification of G0V and a mass similar to the Sun. The spectral characteristics of the smaller companion Delta Trianguli B are not well determined since the close orbit makes observations difficult, with estimates of the spectral class ranging from G9V to K4V. The Delta Trianguli stars orbit their center of mass with an estimated separation of 0.106 AU; it is certainly less than one AU. The orbital period is 10.02 days and the eccentricity of the orbit is only 0.020. The orbit is inclined about 167° to the line of sight from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Trianguli
Gamma Trianguli (Gamma Tri, γ Trianguli, γ Tri) is a star in the constellation Triangulum located approximately 112 light years from Earth. It has an apparent magnitude of +4.01 and forms an optical (line-of-sight) triple with Delta Trianguli and 7 Trianguli. Properties This star has a stellar classification of A1Vnn, which indicates it is an A-type main sequence star. It has 2.7 times the mass of the Sun and nearly double the Sun's radius. Gamma Trianguli is radiating about 33 times the luminosity of the Sun from its outer envelope at an effective temperature of 9,440 K, giving the star a white hue. The star is roughly 300 million years old. Rotation It is rotating rapidly, with a projected rotational velocity of 254 km/s along the equator, which causes the star to take the pronounced shape of an oblate spheroid like Altair. Because the inclination of the star's axial tilt is unknown, this means that the azimuthal equatorial velocity is at leas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Trianguli
Beta Trianguli (Beta Tri, β Trianguli, β Tri) is the Bayer designation for a binary star system in the constellation Triangulum, located about 127 light years from Earth. Although the apparent magnitude is only 3.0, it is the brightest star in the constellation Triangulum. This is a double-lined spectroscopic binary star system with an orbital period of 31.39 days and an eccentricity of 0.53. The members are separated by a distance of less than 5 AU. The primary component has a stellar classification of A5IV, indicating that it has evolved away from the main sequence and is now a subgiant star. However, the classification is uncertain and not consistent with the mass derived from the orbit. It is among the least variable of the stars that were observed by the Hipparcos spacecraft, with a magnitude varying by only 0.0005. Based on observations using the Spitzer Space Telescope, as reported in 2005, this system is emitting an excess of infrare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
56 Andromedae
56 Andromedae, abbreviated 56 And, is a probable binary star system in the northern constellation of Andromeda. ''56 Andromedae'' is the Flamsteed designation. It has a combined apparent visual magnitude of 5.69, which is just bright enough to be dimly visible to the naked eye under good seeing conditions. The distance to this system can be ascertained from its annual parallax shift, measured at with the Gaia space observatory, which yields a separation of 330 light years. It is moving further from the Earth with a heliocentric radial velocity of +62 km/s and is traversing the celestial sphere at a relatively high rate of per year. This pair is positioned near the line of sight to the open cluster NGC 752, located away. The brighter primary is an aging giant star with a stellar classification of K0 III, having exhausted the hydrogen at its core and evolved off the main sequence. It is a red clump giant, having undergone "helium flash" and is presently g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upsilon Andromedae
Upsilon Andromedae (υ Andromedae, abbreviated Upsilon And, υ And) is a binary star located 44 light-years from Earth in the constellation of Andromeda (constellation), Andromeda. The system consists of an F-type main-sequence star (designated υ Andromedae A, officially named Titawin in the Amazigh language ) and a smaller red dwarf. , four Exoplanet, extrasolar planets (designated Upsilon Andromedae b, Upsilon Andromedae c, c, Upsilon Andromedae d, d and Upsilon Andromedae e, e; the first three named Saffar, Samh and Majriti, respectively) are believed to orbit υ Andromedae A. All four are likely to be jovian planets that are comparable in size to Jupiter. This was both the first multiple-planetary system, planet system to be discovered around a main-sequence star, and the first multiple-planet system known in a multiple-star system. Nomenclature ''υ Andromedae'' (Latinisation of names, Latinised to ''Upsilon Andromedae'') is the system's Bayer designation. Under t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chi Andromedae
Chi Andromedae ( Andromedae, And) is the Bayer designation for a star in the northern constellation of Andromeda. It has an apparent visual magnitude of +5.01, which is relatively faint for a naked-eye star. Based upon parallax measurements made during the Gaia mission, Chi Andromedae is located around from Earth. χ Andromedae is a member of (), meaning '' Heaven's Great General'', together with γ Andromedae, φ Persei, 51 Andromedae, 49 Andromedae, θ Andromedae, τ Andromedae, 56 Andromedae, β Trianguli, γ Trianguli and δ Trianguli. Consequently, the Chinese name for χ Andromedae itself is (, en, the Fifth Star of Heaven's Great General.) This is most likely a spectroscopic binary system with an estimated orbital period of 20.8 years and an eccentricity of 0.37. The primary component has a stellar classification of G8 III, which indicates it is a giant star that has exhausted the supply of hydrogen at its core and evolved away from the main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
49 Andromedae
49 Andromedae (abbreviated 49 And) is a star in the constellation Andromeda. ''49 Andromedae'' is the Flamsteed designation though it also bears the Bayer designation A Andromedae. It is visible to the naked eye under good viewing conditions with an apparent visual magnitude of 5.269. The distance to 49 Andromedae, as determined from its annual parallax shift of , is around 314 light-years. It is moving closer to the Sun with a heliocentric radial velocity of −11.5 km/s. With an estimated age of years, this is an aging red-clump giant star with a stellar classification of K0 III, indicating it is generating energy by helium fusion at its core. The spectrum displays "slightly strong" absorption lines of cyanogen (CN). It has 2.07 times the mass of the Sun and has expanded to 11 times the Sun's radius. The star is radiating 71 times the Sun's luminosity from its enlarged photosphere at an effective temperature The effective temperature of a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
51 Andromedae
51 Andromedae, abbreviated 51 And and formally named Nembus , is the 5th brightest star in the northern constellation of Andromeda, very slightly dimmer than the Andromeda Galaxy also being of 4th magnitude. It is an orange K-type giant star with an apparent magnitude of +3.57 and is about 169 light-years from the Earth/solar system. It is traditionally depicted as one of the two northern, far upper ends of the mythological, chained-to-the-rocks princess, the other being binary star system Gamma Andromedae. At an estimated age of 1.7 billion years, this is an evolved red giant star with a stellar classification of . The suffix notation indicates a mild enhancement of cyanogen absorption lines in its spectrum. This star has 1.8 times the mass of the Sun and it has expanded to 21.3 times the Sun's radius. It is radiating 142 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,951 K. Nomenclature ''51 Andromedae'' is the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phi Persei
Phi Persei (Phi Per, φ Persei, φ Per) is a Class B2Vpe fourth-magnitude star in the constellation Perseus, location about 720 light-years from Earth. System Phi Persei is spectroscopic binary consisting of a blue main sequence primary of class B2 and a hot subdwarf secondary. The two stars have an orbit of 217 days and are separated by about . Phi Persei is a runaway star and extrapolating its space velocity backwards by the modelled age of the system (57 million years) places it within the Alpha Persei cluster. The primary star rotates rapidly with a projected equatorial velocity of . Due to its rapid rotation, the primary star has a polar radius about and an equatorial radius of about . With an effective temperature of nearly , it has a bolometric luminosity nearly 15,000 times higher than the Sun. The rapidly-spinning star is surrounded by a circumstellar disk. The binary orbit, the spin of the primary star, and the disk are all seen nearly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Andromedae
Gamma Andromedae, Latinized from γ Andromedae, is the third-brightest point of light in the northern constellation of Andromeda. It is a multiple star system approximately 350 light-years from Earth. The system is drifting closer to the Sun with a radial velocity in the range of −12 to −14 km/s. Observation In 1778, German physicist Johann Tobias Mayer discovered that γ Andromedae is a double star. When examined in a small telescope, it appears to be a bright, golden-yellow star next to a dimmer, indigo-blue star, separated by approximately 10 arcseconds. The pair is often considered by stargazers to be a beautiful double star with a striking contrast of color. The brighter member, γ1 Andromedae, is the primary of the system, and is thus designated component γ Andromedae A. It has the official proper name Almach , which was used as the traditional name of the naked eye star, and thus the system as a whole. The fainter secondary is γ2 And ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
