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Slow Irregular Variable
A slow irregular variable (ascribed the GCVS types L, LB and LC) is a variable star that exhibit no or very poorly defined periodicity in their slowly changing light emissions. These stars have often been little-studied, and once more is learnt about them, they are reclassified into other categories such as semiregular variables. Nomenclature Irregular variable stars were first given acronyms based on the letter "I": ''Ia'', ''Ib''. and ''Ic''. These were later refined so that the I codes were used "nebular" or "rapidly irregular" variable stars such as T Tauri and Orion variables. The remaining irregular stars, cool slowly varying giants and supergiants of type Ib or Ic were reassigned to Lb and Lc. When the General Catalogue of Variable Stars standardised its acronyms to be all uppercase, the codes LB and LC were used. Type Lb ''Slow irregular variables of late spectral types ( K, M, C, S); as a rule, they are giants'' The GCVS also claims to give this type to slow irregular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GCVS
The General Catalogue of Variable Stars (GCVS) is a list of variable stars. Its first edition, containing 10,820 stars, was published in 1948 by the Academy of Sciences of the USSR and edited by B. V. Kukarkin and P. P. Parenago. Second and third editions were published in 1958 and 1968; the fourth edition, in three volumes, was published 1985–1987. It contained 28,435 stars. A fourth volume of the fourth edition containing reference tables was later published, as well as a fifth volume containing variable stars outside the Galaxy. The last edition (GCVS v5.1) based on data compiled in 2015 gathers 52,011 variable stars. The most up-to-date version of the GCVS is available at the GCVS website. It contains improved coordinates for the variable stars in the printed fourth edition of the GCVS, as well as variable stars discovered too recently to be included in the fourth edition. An older version of the GCVS dating from 2004 is available from the VizieR service at the Ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TX Piscium
TX Piscium (19 Piscium) is a variable carbon star in the constellation Pisces. It is amongst the reddest naked eye stars, with a significant reddish hue when seen in binoculars. It is approximately 900 light years from Earth. Spectrum TX Piscium is a very red star, 2.6 magnitudes fainter at blue wavelengths than in the middle of the visual range, and another 3.3 magnitudes fainter in the ultraviolet. It has been given a spectral class C7,2, indicating a relatively cool carbon star with only modest C2 band strength. It has alternately been classified as C-N5 C24, suggesting a warmer star with stronger C2 bands. Spectral features have been observed to vary. Variability The apparent magnitude of TX Piscium varies between +4.9 and +5.5 and it is classified as a slow irregular variable. Photometry has shown some periodicity in the brightness of 224 days, and some spectral variation over 450 days, suggesting the star is not entirely irregular. The star apparently lie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
13 Boötis
13 Boötis is a solitary variable star in the northern constellation of Boötes, and is positioned near the western constellation border with Ursa Major. It has the variable star designation CF Boötis, often abbreviated CF Boo, while ''13 Boötis'' is the star's Flamsteed designation. This star has a reddish hue and is faintly visible to the naked eye with an apparent visual magnitude that fluctuates around 5.26. It is located at a distance of approximately 700 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −14 km/s. This is an aging red giant star on the asymptotic giant branch with a stellar classification of M1.5III, which is interpreted by stellar evolutionary models to mean it has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. It is classified as a slow irregular variable of the Lb type, and its brightness has been observed to vary from +5.29 down to +5.38. The star ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tau4 Eridani
Tau4 Eridani (τ4 Eridani, τ4 Eri) is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.65. The distance to this star can be estimated using the parallax method, which yields a value of roughly 300 light years. This is an evolved red giant star currently on the asymptotic giant branch with a stellar classification of M3/4 III. It is a slow irregular variable star of type Lb, undergoing changes in magnitude over the range 3.57−3.72 with a periodicity of 23.8 d. The measured angular diameter of Tau4 Eridani is . At its estimated distance, this yields a physical size of about 106 times the radius of the Sun. It shines with 1,537 times the luminosity of the Sun from an outer atmosphere at an effective temperature of 3,712 K. This is most likely a binary star system. The companion is a magnitude 9.5 star at an angular separation of 5.7 ″ along a position angle of 291°, as of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camelopardalis
Camelopardalis is a large but faint constellation of the northern sky representing a giraffe. The constellation was introduced in 1612 or 1613 by Petrus Plancius. Some older astronomy books give Camelopardalus or Camelopardus as alternative forms of the name, but the version recognized by the International Astronomical Union matches the genitive form, seen suffixed to most of its key stars. Etymology First attested in English in 1785, the word ''camelopardalis'' comes from Latin, and it is the romanization of the Greek "καμηλοπάρδαλις" meaning "giraffe", from "κάμηλος" (''kamēlos''), "camel" + "πάρδαλις" (''pardalis''), " spotted", because it has a long neck like a camel and spots. Features Stars Although Camelopardalis is the 18th largest constellation, it is not a particularly bright constellation, as the brightest stars are only of fourth magnitude. In fact, it only contains four stars brighter than magnitude 5.0. * α Cam is a blue-hued su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BE Camelopardalis
BE Camelopardalis is a solitary variable star in the northern circumpolar constellation of Camelopardalis. It is visible to the naked eye as a faint, red-hued point of light with an apparent visual magnitude that fluctuates around 4.39. The star is located roughly 800 light years away from the Sun based on stellar parallax. This object is an M-type bright giant with a stellar classification of M2 II, and is currently on the asymptotic giant branch. It is classified as an irregular variable of subtype Lc and its brightness varies from magnitude +4.35 down to +4.48. Having exhausted the supply of hydrogen at its core, the star has expanded to around 176 times the Sun's radius. It has 2.9 times the Sun's mass and is radiating over four thousand times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 3,615 K. References {{DEFAULTSORT:BE Camelopardalis M-type bright giants Asymptotic-giant-branch stars Slow irregula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gemini (constellation)
Gemini is one of the constellations of the zodiac and is located in the northern celestial hemisphere. It was one of the 48 constellations described by the 2nd century AD astronomer Ptolemy, and it remains one of the 88 modern constellations today. Its name is Latin for ''twins'', and it is associated with the twins Castor and Pollux in Greek mythology. Its old astronomical symbol is (♊︎). Location Gemini lies between Taurus to the west and Cancer to the east, with Auriga and Lynx to the north, Monoceros and Canis Minor to the south and Orion to the south-west. In classical antiquity, Cancer was the location of the Sun on the first day of summer (June 21). During the first century AD, axial precession shifted it into Gemini. In 1990, the location of the Sun on the first day of summer moved from Gemini into Taurus, where it will remain until the 27th century AD and then move into Aries. The Sun will move through Gemini from June 21 to July 20 through 2062. Gemini i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mu Geminorum
Mu Geminorum or μ Geminorum, formally named Tejat (), is a single star in the northern constellation of Gemini. From parallax measurements obtained during the Hipparcos mission, it is roughly distant from the Sun. The position of the star near the ecliptic means that it is subject to lunar occultations. Mu Geminorum forms the primary or 'A' component of a double star system designated WDS J06230+2231 along with UCAC2 39641417 (also designated WDS J06230+2231BC), itself a binary pair. Nomenclature ''μ Geminorum'' ( Latinised to ''Mu Geminorum'') is the star's Bayer designation. WDS J06230+2231 is the double star's designation in the Washington Double Star Catalog. The designations of the double star's components as WDS J06230+2231A and BC derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). Mu Geminorum bore the traditional name of ''Tejat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taurus (constellation)
Taurus (Latin for "the Bull") is one of the constellations of the zodiac and is located in the northern celestial hemisphere. Taurus is a large and prominent constellation in the Northern Hemisphere's winter sky. It is one of the oldest constellations, dating back to the Early Bronze Age at least, when it marked the location of the Sun during the spring equinox. Its importance to the agricultural calendar influenced various bull figures in the mythologies of Ancient Sumer, Akkad, Assyria, Babylon, Egypt, Greece, and Rome. Its old astronomical symbol is (♉︎), which resembles a bull's head. A number of features exist that are of interest to astronomers. Taurus hosts two of the nearest open clusters to Earth, the Pleiades and the Hyades, both of which are visible to the naked eye. At first magnitude, the red giant Aldebaran is the brightest star in the constellation. In the northeast part of Taurus is Messier 1, more commonly known as the Crab Nebula, a supernova remnant co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aldebaran
Aldebaran (Arabic: “The Follower”, "الدبران") is the brightest star in the zodiac constellation of Taurus. It has the Bayer designation α Tauri, which is Latinized to Alpha Tauri and abbreviated Alpha Tau or α Tau. Aldebaran varies in brightness from an apparent visual magnitude 0.75 down to 0.95, making it (typically) the fourteenth-brightest star in the night sky. It is located at a distance of approximately 65 light-years from the Sun. The star lies along the line of sight to the nearby Hyades cluster. Aldebaran is a giant star that is cooler than the Sun with a surface temperature of , but its radius is about 44 times the Sun's, so it is over 400 times as luminous. It spins slowly and takes 520 days to complete a rotation. Aldebaran is believed to host a planet several times the mass of Jupiter, named . The planetary exploration probe Pioneer 10 is heading in the general direction of the star and should make its closest approach in about two million ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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