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Acamar
Theta Eridani, Latinized from θ Eridani, is a binary system in the constellation of Eridanus with a combined apparent magnitude of 2.88. Its two components are designated θ1 Eridani, formally named Acamar (the traditional name of the system), and θ2 Eridani. The system's distance from the Sun based on parallax measurements is approximately 165 light-years. Nomenclature Theta Eridani is the system's Bayer designation; θ1 and θ2 Eridani those of its two components. The system bore the traditional name Acamar, derived from the Arabic آخِر النَّهْر ''Ākhir an-nahr'', which means "the end of the river", via a Roman-alphabet handwriting misread "rn" to "m". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems. It approved the name "Acamar" for θ1 Eridani on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eridanus (constellation)
Eridanus () is a constellation in the southern celestial hemisphere. It is represented as a river. One of the 48 constellations listed by the 2nd century astronomer Ptolemy, it remains one of the 88 modern constellations. It is the sixth largest of the modern constellations, and the one that extends farthest in the sky from north to south. The same name was later taken as a Latin name for the real Po River and also for the name of a minor river in Athens. Features Stars At its southern end is the magnitude 0.5 star Achernar, designated Alpha Eridani. It is a blue-white hued main sequence star 144 light-years from Earth, whose traditional name means "the river's end". Achernar is a very peculiar star because it is one of the flattest stars known. Observations indicate that its radius is about 50% larger at the equator than at the poles. This distortion occurs because the star is spinning extremely rapidly. There are several other noteworthy stars in Eridanus, including so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Achernar
Achernar is the brightest star in the constellation of Eridanus, and the ninth-brightest in the night sky. It has the Bayer designation Alpha Eridani, which is Latinized from α Eridani and abbreviated Alpha Eri or α Eri. The name Achernar applies to the primary component of a binary system. The two components are designated Alpha Eridani A (the primary) and B (the secondary), with the latter known informally as Achernar B. As determined by the ''Hipparcos'' astrometry satellite, this system is located at a distance of approximately from the Sun. Of the ten apparent brightest stars in the night-time sky, Alpha Eridani is the hottest and bluest in color, due to Achernar being of spectral type B. Achernar has an unusually rapid rotational velocity, causing it to become oblate in shape. The secondary is smaller, of spectral type A, and orbits Achernar at a distance of . Nomenclature ''α Eridani'' ( Latinised to ''Alpha Eridani'') is the system's Bayer designation. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north pole, with 0° at the Equator. Lines of constant latitude, or ''parallels'', run east–west as circles parallel to the equator. Latitude and ''longitude'' are used together as a coordinate pair to specify a location on the surface of the Earth. On its own, the term "latitude" normally refers to the ''geodetic latitude'' as defined below. Briefly, the geodetic latitude of a point is the angle formed between the vector perpendicular (or ''normal'') to the ellipsoidal surface from the point, and the plane of the equator. Background Two levels of abstraction are employed in the definitions of latitude and longitude. In the first step the physical surface is modeled by the geoid, a surface which approximates the mean sea level over the ocea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 24160
HD 24160 is a single star in the equatorial constellation of Eridanus. It is visible to the naked eye with an apparent visual magnitude of 4.17. The distance to HD 24160 can be estimated from its annual parallax shift of , yielding a separation of 217 light years. It is moving further from the Earth with a heliocentric radial velocity of +2 km/s. This object is a coronal member of the Ursa Major Moving Group of stars that share a common motion through space. At the age of 1.76 billion years old, HD 24160 is an evolved G-type giant star with a stellar classification of G7 III, having consumed the hydrogen at its core and tracked away from the main sequence. It has 2.33 times the mass of the Sun and has expanded to about 11 times the Sun's radius. The star is radiating 81.3 times the Sun's luminosity The solar luminosity (), is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the lum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 23319
HD 23319 (h Eridani) is an orange-hued star in the constellation Eridanus. It has an apparent visual magnitude of 4.59, which is sufficiently bright to make it visible to the naked eye. The distance to HD 23319 can be estimated from its annual parallax shift of , which yields a range of about 170 light years. It is moving further away from the Earth with a heliocentric radial velocity of +9.9 km/s. This is an aging giant star with a stellar classification of , where the suffix notation indicates the spectrum shows a mild overabundance of the cyano radical. It is a red clump giant, indicating it is on the horizontal branch and is generating energy through helium fusion at its core. The star has 1.2 times the mass of the Sun and, at the age of 4.6 billion years, has expanded to 11 times the Sun's radius. It is radiating 63 times the Sun's luminosity The solar luminosity (), is a unit of radiant flux (power emitted in the form of photons) convention ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 16754
HD 16754 is a binary or triple-star system in the constellation Eridanus. It has the Bayer designation s Eridani; ''HD 16754'' is the designation from the '' Henry Draper catalogue''. The system is visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.74. It is located at a distance of approximately 132 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +18 km/s. The system is a member of the Columba association of co-moving stars. This object was flagged as an astrometric binary based on proper motion measurements made from the Hipparcos spacecraft. Zuckerman et al. (2011) consider it a multi-star system, with a bright A-type primary plus a faint M-type companion at an angular separation of to the north. The astrometric companion to the primary remains unresolved. The main component is an A-type main-sequence star with a stellar classification of A1 Vb. Based u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kappa Eridani
Kappa Eridani, Latinized from κ Eridani, is a solitary star in the constellation Eridanus. With an apparent visual magnitude of 4.25, it is bright enough to be visible to the naked eye on a dark night. Based upon an annual parallax shift of 0.00642 arc seconds, it is roughly 510 light years distant from the Sun. This appears to be an evolving B-type subgiant star with a stellar classification of B7 IV. The measured angular diameter is . At an estimated distance of Kappa Eridani, this yields a physical size of about six times the radius of the Sun. It has five times the Sun's mass, and radiates 1,175 times the solar luminosity from its outer atmosphere at an effective temperature of 14,700 K. Kappa Eridani is spinning with a projected rotational velocity Stellar rotation is the angular motion of a star about its axis. The rate of rotation can be measured from the spectrum of the star, or by timing the movements of active features on the surfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phi Eridani
φ Eridani (Latinised as Phi Eridani) is a star in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.55. The distance to this star, as determined using the parallax method, is around 154 light-years. This is a B-type star with a stellar classification of B8IV-V, suggesting it shows traits of a main-sequence star and a subgiant. It is spinning rapidly with a projected rotational velocity of 250 km/s. This rotation is giving the star an oblate shape with an equator that is 17% larger than the polar radius. The estimated angular size is 0.68 milliarcseconds. Since the distance is known, this yields a physical size of around 3.4 times the radius of the Sun. It has 3.55 times the mass of the Sun and radiates 255 times the solar luminosity The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chi Eridani
χ Eridani (Latinised as Chi Eridani) is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.70. The distance to this system, as determined using the parallax method, is around 58 light years. The pair had an angular separation of 5.0 arcseconds as of 1994. This corresponds to a projected separation of around 128 AU. The primary component is an evolving G-type subgiant star with a stellar classification of G8 IV. It is about 1.6 times the mass of the Sun and has 4 times the Sun's radius. The star shines with 10 times the solar luminosity The solar luminosity (), is a unit of radiant flux ( power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun. One nominal ... from its outer atmosphere at an effective temperature of 5,115 K. Unusually for a s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asterism (astronomy)
An asterism is an observed pattern or group of stars in the sky. Asterisms can be any identified pattern or group of stars, and therefore are a more general concept than the formally defined 88 constellations. Constellations are based on asterisms, but unlike asterisms, constellations outline and today completely divide the sky and all its celestial objects into regions around their central asterisms. For example, the asterism known as the Big Dipper comprises the seven brightest stars in the constellation Ursa Major. Another is the asterism of the Southern Cross, within the constellation of Crux. Asterisms range from simple shapes of just a few stars to more complex collections of many stars covering large portions of the sky. The stars themselves may be bright naked-eye objects or fainter, even telescopic, but they are generally all of a similar brightness to each other. The larger brighter asterisms are useful for people who are familiarizing themselves with the night sky ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Net (Chinese Constellation)
The Net mansion () is one of the Twenty-eight mansions of the Chinese constellations. It is one of the western mansions of the White Tiger The white tiger or bleached tiger is a leucistic pigmentation variant of the Mainland tiger. It is reported in the wild from time to time in the Indian states of Madhya Pradesh, Assam, West Bengal, Bihar, Odisha, in the Sunderbans region and .... Asterisms References {{DEFAULTSORT:Net (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
