|
List Of Stars In Reticulum
This is the list of notable stars in the constellation Reticulum, sorted by decreasing brightness. See also *List of stars by constellation References ;Notes ;Bibliography * * * * * * * {{Stars of Reticulum Reticulum, *List Lists of stars by constellation, Reticulum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night, but their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye, all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beta Reticuli
Beta Reticuli (Beta Ret, β Reticuli, β Ret) is binary star system in southern constellation of Reticulum. It is visible to the naked eye with an apparent visual magnitude of +3.84. Based upon an annual parallax shift of 33.49 mas, it is located some 97 light years from the Sun. This is a single-lined spectroscopic binary with an orbital period of 5.25 years and an eccentricity of 0.33. The primary, component A, is an evolved K-type giant star with a stellar classification of K0 IVSB:. It is between 5 and 6 billion years old, with 1.2 times the mass of the Sun and 9.3 times the Sun's radius. The companion, component B, is most likely a red dwarf with a classification in the range M0–M4. During the mid-20th century, the Dutch-American astronomer Willem Jacob Luyten proposed that the G3V star HD 24293 formed a third component of this system, based upon similar proper motions. However, this was subsequently ruled out based ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eta Reticuli
Eta Reticuli, Latinized from η Reticuli, is a solitary star in the southern constellation of Reticulum. With an apparent visual magnitude of 5.22, it is faintly visible to the naked eye on a dark night. Based upon an annual parallax shift of 8.48 mas, it is located at a distance of roughly 385 light years from the Sun. It may be a member of the high-velocity Zeta Herculis Moving Group of stars that share a common motion through space. This is an evolved G-type giant star with a stellar classification of G7 III. Based upon stellar models, it has an estimated 2.54 times the mass of the Sun and 13.24 times the Sun's radius. With an age of around 1.17 billion years, it is radiating 120 times the solar luminosity from its outer atmosphere at an effective temperature of 4,948 K. Eta Reticuli is moving through the Galaxy at a speed of 117.6 km/s relative to the Sun. Its projected Galactic orbit carries it between 11,700 and 31,600 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Reticuli
Zeta Reticuli, Latinized from ζ Reticuli, is a wide binary star system in the southern constellation of Reticulum. From the southern hemisphere the pair can be seen with the naked eye as a double star in very dark skies. Based upon parallax measurements, this system is located at a distance of about from Earth. Both stars are solar analogs that have characteristics similar to those of the Sun. They belong to the Zeta Herculis Moving Group of stars that share a common origin. Nomenclature At a declination of −62°, the system is not visible from Britain's latitude of +53°, so it never received a Flamsteed designation in John Flamsteed's 1712 ''Historia Coelestis Britannica''. The Bayer designation for this star system, Zeta (ζ) Reticuli, originated in a 1756 star map by the French astronomer Abbé Nicolas-Louis de Lacaille. Subsequently, the two stars received separate designations in the Cape Photographic Durchmusterung, which was processed between 1859 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iota Reticuli
ι Reticuli, Latinized as Iota Reticuli, is a solitary, orange-hued star in the southern constellation of Reticulum. It is faintly visible to the naked eye, having a combined apparent visual magnitude of +4.97. Based upon an annual parallax shift of 10.22 mas as seen from Earth, it is located around 319 light years from the Sun. At present it is receding from the Sun with a radial velocity of +61 km/s, having come closest to the Sun 883,000 years ago at a distance of 212 light years. Iota Reticuli is moving through the Galaxy at a speed of 80.9 km/s relative to the Sun. Its projected Galactic orbit carries it between 12,300 and 25,100 light years from the center of the Galaxy. This is an evolved K-type giant star with a stellar classification of K4 III. Having exhausted the supply of hydrogen at its core, the star cooled and expanded off the main sequence; at present it has 24 times the girth of the Sun. It is radiating 180 times the lumi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kappa Reticuli
Kappa Reticuli (κ Reticuli) is a binary star system in the southern constellation of Reticulum. It is visible to the naked eye, having a combined apparent visual magnitude of +4.71. Based upon an annual parallax shift of 46.12 mas as seen from Earth, it is located 71 light-years from the Sun. Based upon its space velocity components, this star is a member of the Hyades supercluster of stars that share a common motion through space. Houk and Cowley (1978) catalogued the yellow-hued primary, component A, with a stellar classification of F3 IV/V, indicating this is an F-type star that showing mixed traits of a main-sequence and a more evolved subgiant star. Later, Grey et al. (2006) listed a class of F3 V, suggesting it is an F-type main-sequence star. It is emitting a statistically significant amount of infrared excess, suggesting the presence of an orbiting debris disk. The secondary, component B, is an orange-hued star with a visu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Irregular Variable
An irregular variable is a type of variable star in which variations in brightness show no regular periodicity. There are two main sub-types of irregular variable: eruptive and pulsating. Eruptive irregular variables are divided into three categories: * Group I variables are split into subgroups IA (spectral types O to A) and IB (spectral types F through M). * Orion variables, GCVS type IN (irregular and nebulous), indigenous to star-forming regions, may vary by several magnitudes with rapid changes of up to 1 magnitude in 1 to 10 days, are similarly divided by spectral type into subgroups INA and INB, but with the addition of another subgroup, INT, for T Tauri stars, or INT(YY) for YY Orionis stars. * The third category of eruptive irregulars are the IS stars, which show rapid variations of 0.5 to 1 magnitude in a few hours or days; again, these come in subgroups ISA and ISB. Pulsating irregular giants or supergiants, called slow irregular variable A slow irregular variable (asc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Reticuli
Delta Reticuli (Delta Ret, δ Reticuli, δ Ret) is a star in the southern constellation of Reticulum. It is visible to the naked eye, having an apparent visual magnitude of 4.60. The distance to this star, as estimated from its annual parallax shift of 6.20 mas, is roughly 530 light-years from the Sun. This is an evolved red giant star on the asymptotic giant branch, having a stellar classification of M2 III. It has expanded to around 56 times the radius of the Sun and radiates 1,100 times the solar luminosity from its cool outer atmosphere at an effective temperature of 3,891 K. Delta Reticuli is moving through the Milky Way at a speed of 13.3 km/s relative to the Sun. Its projected galactic orbit carries it between 22,700 and 30,400 light-years from the center of the galaxy. References {{DEFAULTSORT:Delta Reticuli M-type giants Asymptotic-giant-branch stars Reticulum Reticuli, Delta Durchmusterung objects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiregular Variable
In astronomy, a semiregular variable star, a type of variable star, is a giant or supergiant of intermediate and late (cooler) spectral type showing considerable periodicity in its light changes, accompanied or sometimes interrupted by various irregularities. Periods lie in the range from 20 to more than 2000 days, while the shapes of the light curves may be rather different and variable with each cycle. The amplitudes may be from several hundredths to several magnitudes (usually 1-2 magnitudes in the V filter). Classification The semiregular variable stars have been sub-divided into four categories for many decades, with a fifth related group defined more recently. The original definitions of the four main groups were formalised in 1958 at the tenth general assembly of the International Astronomical Union (IAU). The General Catalogue of Variable Stars (GCVS) has updated the definitions with some additional information and provided newer reference stars where old examples such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Reticuli
Gamma Reticuli (Gamma Ret, γ Reticuli, γ Ret) is a solitary star in the southern constellation of Reticulum. With an apparent visual magnitude of 4.5, it can be faintly seen with the naked eye. Based upon an annual parallax shift of 6.95 mas, it is located roughly 469 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.08 due to interstellar dust. This is an evolved red giant star, currently on the asymptotic giant branch, with a stellar classification of M4 III. It is a semiregular variable with a period of 25 days. Gamma Reticuli has 1.5−2 times the mass of the Sun, 115 times the Sun's radius, and radiates 1,846 times the solar luminosity from its outer atmosphere at an effective temperature of 3,450 K. Gamma Reticuli is moving through the Galaxy at a speed of 24.8 km/s relative to the Sun. Its projected Galactic orbit carries it between 24,100 and 39,2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Reticuli B
Epsilon Reticuli b, sometimes designated Epsilon Reticuli Ab to distinguish from the white dwarf companion of the primary star Epsilon Reticuli, also known as HD 27442, was discovered on December 16, 2000 by the Anglo-Australian Planet Search Team using the radial velocity method. The planet's mass is at least 56% greater than Jupiter mass, a more accurate estimate requiring its inclination to be known. The planet orbits its parent star relatively close, and with more than twice the eccentricity of Earth's orbit. Based on its mass, it is almost certainly a gas giant A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" .... References External links * The Extrasolar Planets Encyclopaedia [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extrasolar Planet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit (astronomy), Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, List of multiplanetary systems, multiple planets have been observed around a star. About 1 in 5 Solar analog, Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type star, K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
