|
Eta Serpentis
Eta Serpentis, Latinized from η Serpentis, is a star in the constellation Serpens. In particular, it lies in Serpens Cauda, the snake's tail. The star has an apparent visual magnitude of 3.260, making it visible to the naked eye. Parallax measurements give a distance estimate of from the Earth. This star is larger than the Sun, with twice the mass and almost six times the radius. The spectrum matches a stellar classification of K0 III-IV, with the luminosity class of III-IV corresponding to an evolved star that lies between the subgiant and giant stages. The expanded outer envelope star is radiating about 19 times the luminosity of the Sun at an effective temperature of . At this temperature, it has an orange hue typical of a K-type star. Eta Serpentis displays solar-like oscillations with a period of 0.09 of a day. Eta Serpentis was previously classified as a carbon star, which would have made it the brightest carbon star in the sky, although this classif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpens
Serpens ( grc, , , the Serpent) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International Astronomical Union. It is unique among the modern constellations in being split into two non-contiguous parts, Serpens Caput (Serpent Head) to the west and Serpens Cauda (Serpent Tail) to the east. Between these two halves lies the constellation of Ophiuchus, the "Serpent-Bearer". In figurative representations, the body of the serpent is represented as passing behind Ophiuchus between Mu Serpentis in ''Serpens Caput'' and Nu Serpentis in ''Serpens Cauda''. The brightest star in Serpens is the red giant star Alpha Serpentis, or Unukalhai, in Serpens Caput, with an apparent magnitude of 2.63. Also located in Serpens Caput are the naked-eye globular cluster Messier 5 and the naked-eye variables R Serpentis and Tau4 Serpentis. Notable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar-like Oscillations
Solar-like oscillations are oscillations in stars that are excited in the same way as those in the Sun, namely by turbulent convection in its outer layers. Stars that show solar-like oscillations are called solar-like oscillators. The oscillations are standing pressure and mixed pressure-gravity modes that are excited over a range in frequency, with the amplitudes roughly following a bell-shaped distribution. Unlike opacity-driven oscillators, all the modes in the frequency range are excited, making the oscillations relatively easy to identify. The surface convection also damps the modes, and each is well-approximated in frequency space by a Lorentzian curve, the width of which corresponds to the lifetime of the mode: the faster it decays, the broader is the Lorentzian. All stars with surface convection zones are expected to show solar-like oscillations, including cool main-sequence stars (up to surface temperatures of about 7000K), subgiants and red giants. Because of the small am ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theta Serpentis
Theta Serpentis (θ Serpentis, abbreviated Theta Ser, θ Ser) is a triple star system in the constellation of Serpens. It consists of a binary pair designated Theta Serpentis AB and whose two components are designated Theta¹ Serpentis or Theta Serpentis A (officially named Alya , the traditional name for the entire system) and Theta² Serpentis or Theta Serpentis B, together with a third visual companion Theta Serpentis C. Based upon parallax measurements obtained during the Hipparcos mission, θ Serpentis AB is approximately 160 light-years, and θ Serpentis C approximately 86 light-years, from the Sun. Nomenclature ''θ Serpentis'' ( Latinised to ''Theta Serpentis'') is the system's Bayer designation; ''θ¹'' and ''θ² Serpentis'' those of the brightest two components. The designations of the two constituents as ''Theta Serpentis AB'' and ''C'', and those of ''AB's'' components - ''Theta Serpentis A'' and ''B'' - derive from the convention used by the Washing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ζ Aquilae
Zeta Aquilae, or ζ Aquilae, is a binary star system in the equatorial constellation of Aquila. It is readily visible with the naked eye, being of the third magnitude. Based on parallax measurements obtained during the Hipparcos mission, it is approximately distant from the Sun. It is a candidate member of the TW Hydrae association of co-moving stars. Zeta Aquilae's two components can be designated Zeta Aquilae A (officially named Okab , the traditional name for the system) and B. Zeta Aquilae has a number of companions listed and together they are designated WDS J19054+1352. As the primary star of this group, Zeta Aquilae also bears the designation WDS J19054+1352A. The companions are then designated WDS J19054+1352B, C, D and E. Nomenclature ''ζ Aquilae'', Latinised to ''Zeta Aquilae'', is the binary's Bayer designation. The designations of the two components as ''Zeta Aquilae A'' and ''B'' derive from the convention used by the Washington Mul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
η Ophiuchi
Eta Ophiuchi (η Ophiuchi, abbreviated Eta Oph, η Oph) is a binary star in the constellation of Ophiuchus. Based on parallax measurements taken during the Hipparcos mission, it is approximately 88 light-years from the Sun. Eta Ophiuchi is part of a multiple star system designated WDS J17104-1544. It itself is designated WDS J17104-1544AB and its two components WDS J17104-1544A (also called Sabik , the traditional name for the system) and WDS J17104-1544B. The 'C' component is UCAC4 372-080717 and 'D' is UCAC2 26022336. Nomenclature ''η Ophiuchi'' ( Latinised to ''Eta Ophiuchi'') is the system's Bayer designation. WDS J17104-1544AB is its designation in the Washington Double Star Catalog. The designations of the two components as WDS J17104-1544 A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU). It bore the traditional name ''Sabik'', from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
112 Herculis
112 Herculis is a binary star system in the northern constellation of Hercules. It is dimly visible to the naked eye with a combined apparent visual magnitude of 5.43. The secondary component is about two magnitudes fainter than the primary star. The distance to this system is approximately 415 light years based on parallax measurements. It is drifting closer to the Sun with a radial velocity of −20 km/s. The binary character of this system was discovered by W. F. Meyer in 1926. By measuring the variation in velocity of the primary component, he determined an orbital period of 6.3624 days. K. Osawa in 1959 found a stellar classification of A4 III for the pair. W. P. Bidelman observed that the primary has unusually strong lines of ionized phosphorus, and it was assigned to the class of peculiar manganese stars by W. L. W. Sargent and L. Searle in 1962, with a resulting spectral type of B9. No evidence was found for a strong magnetic field by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
O Herculis
Omicron Herculis, Latinized from o Herculis, is a star in the constellation Hercules. It used to be called Masym ("the wrist"), but this name was transferred to Lambda Herculis. Properties Omicron Herculis is a B9.5III star approximately 106 pc from the Earth. It has an apparent magnitude of 3.83. The star radiates with a bluish-white hue, and has a luminosity approximately 355 times as bright as the Sun. Omicron Herculis is 3.49 solar masses. Stellar evolutionary caclulations show that it has just left the main sequence. Omicron Herculis is an eruptive variable of the Gamma Cassiopeiae class, which are rapidly rotating B-class stars with mass outflow. It has a projected rotational velocity of 194 km/s. Some sources list Omicron Herculis as being both spectroscopic and an interferometric binary star with a separation of about 60 milliarcseconds, although the companion star has not been confirmed. Omicron Hercules is notable for residing close to the co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
μ Herculis
Mu Herculis (μ Herculis) is a nearby quadruple star system about 27.1 light years from Earth in the constellation Hercules. Its main star, Mu Herculis A is fairly similar to the Sun although more highly evolved with a stellar classification of G5 IV. Since 1943, the spectrum of this star has served as one of the stable anchor points by which other stars are classified. Its mass is about 1.1 times that of the Sun, and it is beginning to expand to become a giant. Etymology In the catalogue of stars in the ''Calendarium of Al Achsasi Al Mouakket'', this star was designated ''Marfak Al Jathih Al Aisr'', which was translated into Latin as ''Cubitum Sinistrum Ingeniculi'', meaning ''the left elbow of kneeling man''. In Chinese, (), the '' Left Wall of Heavenly Market Enclosure'', refers to an asterism which represents eleven old states in China, marking the left borderline of the enclosure, consisting of μ Herculis, δ Herculis, λ Herculis, ο H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
λ Herculis
Lambda Herculis (λ Herculis. abbreviated Lambda Her, λ Her), formally named Maasym , is a star in the constellation of Hercules. From parallax measurements taken during the Gaia mission, it is approximately 393 light-years from the Sun. Nomenclature ''λ Herculis'' ( Latinised to ''Lambda Herculis'') is the star's Bayer designation. It bore the traditional name ''Maasym'', from the Arabic مِعْصَم ''miʽṣam'' "wrist". In 2016, the International Astronomical Union organized a Working Group on Star Names (WGSN) to catalogue and standardize proper names for stars. The WGSN approved the name ''Maasym'' for this star on 12 September 2016 and it is now so included in the List of IAU-approved Star Names. In Chinese, (), meaning '' Left Wall of Heavenly Market Enclosure'', refers to an asterism which represents eleven old states in China and which is marking the left borderline of the enclosure, consisting of Lambda Herculis, Delta Herculis, Mu Herculis, Omicro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
δ Herculis
Delta Herculis (δ Herculis, abbreviated Delta Her, δ Her) is a multiple star system in the constellation of Hercules. Its light produces to us apparent magnitude 3.12, as such the third-brightest star in the large, fairly dim constellation. Based on parallax measurement taken during the Hipparcos mission, it is approximately from the Sun. Components It consists of a binary pair, designated Delta Herculis A, together with three potential companions, suffixed B, C and D. Furthermore B is believed to be an optical binary. A's components are designated Delta Herculis Aa (officially named Sarin , the traditional name of the system) and Ab. The angular separation between the main component A and the component B, which has a magnitude of 8.74, is 8.5 arcsecond Nomenclature ''δ Herculis'' ( Latinisation of names, Latinised to ''Delta Herculis'') is the system's Bayer designation. The designations of the four constituents as ''Delta Herculis A'', ''B'', ''C'' and ''D'' ... [...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] |
Heavenly Market Enclosure
The Heavenly Market Enclosure (天市垣, ''Tian Shi Yuan''), is one of the ''San Yuan'' or Three enclosures. Stars and constellations of this group are visible during late summer and early autumn in the Northern Hemisphere (late winter and early spring in the Southern). The Summer Triangle lies directly to the northeast. Asterisms The asterisms are : See also * Twenty-eight mansions * Summer Triangle The Summer Triangle is an astronomical asterism in the northern celestial hemisphere. The defining vertices of this imaginary triangle are at Altair, Deneb, and Vega, each of which is the brightest star of its constellation ( Aquila, Cygnu ... Chinese constellations {{china-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
