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β Lupi
Beta Lupi (Romanization of Greek, Latinized from β Lupi) or Kekouan (), is a star in the southern constellation of Lupus (constellation), Lupus. It has an apparent visual magnitude of 2.7, making it readily visible to the naked eye. Based upon parallax measurements, this star is located at a distance of about from Earth. Properties The stellar classification of B2 III indicates this is a giant star. The effective temperature of the star's outer envelope is 24,090 K, giving it the blue-white hue of a B-type star. With an age of around 25 million years, it is near the end of its Stellar Evolution, hydrogen phase, where hydrogen is fused into the chemical element, element helium, and transferring into a red supergiant star. At about 8.8 solar masses, it may have enough mass to end its life as a Type II supernova, but there is the possibility of Beta Lupi becoming a white dwarf. This is a multi-period Beta Cephei variable with a dominant oscillation period of 0.23 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lupus (constellation)
Lupus is a constellation of the mid-Southern Sky. Its name is Latin for wolf. Lupus was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one of the IAU designated constellations, 88 modern constellations but was long an Asterism (astronomy), asterism associated with the just westerly, larger constellation Centaurus. History and mythology In ancient times, the constellation was considered an Asterism (astronomy), asterism within Centaurus, and was considered to have been an arbitrary animal, killed, or about to be killed, on behalf of, or for, Centaurus. An alternative visualization, attested by Eratosthenes, saw this constellation as a wineskin held by Centaurus. It was not separated from Centaurus until Hipparchus, Hipparchus of Bithynia named it ( meaning "beast") in the 2nd century BC. The Greek constellation is probably based on the Babylonian figure known as the Uridimmu, Mad Dog (UR.IDIM). This was a strange hybrid creature that c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
White Dwarf
A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place in a white dwarf; what light it radiates is from its residual heat. The nearest known white dwarf is Sirius B, at 8.6 light years, the smaller component of the Sirius binary star. There are currently thought to be eight white dwarfs among the hundred star systems nearest the Sun. The unusual faintness of white dwarfs was first recognized in 1910. The name ''white dwarf'' was coined by Willem Jacob Luyten in 1922. White dwarfs are thought to be the final stellar evolution, evolutionary state of stars whose mass is not high enough to become a neutron star or black hole. This includes over 97% of the stars in the Milky Way. After the hydrogen-stellar nucleosynthesis, fusing period of a main sequence, main-sequence star of Stellar mass, lo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Lupi
Epsilon Lupi, Latinized from ε Lup, is a multiple star system in the southern constellation of Lupus. At an apparent visual magnitude of 3.41, Epsilon Lupi can be readily viewed from the southern hemisphere with sufficiently dark skies. It is the fifth-brightest star or star system in the constellation. Parallax measurements give a distance to this system of roughly . This system is what astronomers term a double-lined spectroscopic binary. When the spectrum is examined, the absorption line features of both stars can be viewed. As a result of the Doppler effect, these lines shift back and forth in frequency as the two stars orbit around each other. This allows some of their orbital elements to be deduced, even though the individual stars have not been resolved with a telescope. The pair share a close, elliptical orbit with a period of 4.55970 days. The orbital eccentricity is 0.277, which means that at the separation at closest approach, or periapsis, is only 57% ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lambda Lupi
Lambda Lupi, Latinized from λ Lupi, is a triple star system in the southern constellation of Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.04. Based upon an annual parallax shift of just 4.20 mas as seen from Earth, it is located roughly 800 light years from the Sun. The system has a peculiar velocity of relative to its neighbors, making it a candidate runaway star system. It is a member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association. The two visible components of this system orbit each other over a period of 70.8 years with a large eccentricity of 0.63. The primary component has a visual magnitude of 4.43, while the secondary is of magnitude 5.23. Both are B-type main sequence stars with a stellar classification of B3 V. One of the pair is itself a double-lined spectroscopic binary A binary star or binary star system is a system of two stars that are gravitationally bou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kappa Centauri
Kappa Centauri (κ Cen, κ Centauri) is a binary star in the southern constellation of Centaurus. With an apparent visual magnitude of +3.14, it can be viewed with the naked eye on a dark night. Parallax measurements place it at an estimated distance of from Earth. Characteristics This is a spectroscopic binary system where the presence of an orbiting companion is revealed by shifts in the absorption lines caused by the Doppler effect. They take 58 years to complete an orbit, have a small orbital eccentricity, eccentricity of 0.304, and are seen orbiting nearly edge-on. The primary component has about 8.4 times the Sun's mass and four times the Sun's radius. It has a stellar classification of B2V, indicating that it is in the main sequence stage of its stellar evolution. An effective temperature of in the outer envelope is what gives it the blue-white hue of a B-type star. It is a candidate Beta Cephei variable that shows line-profile variations in its stellar spectrum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Lupi
Delta Lupi (δ Lupi, δ Lup) is a star in the southern circumpolar constellation of Lupus. In traditional Chinese astronomy, it is "the 2nd (star) of the Cavalry Officer" (騎官二). With an apparent visual magnitude of 3.2, it is the fourth-brightest star in the constellation. The distance to this star has been measured using the parallax technique, yielding an estimate of roughly 900 light-years with a 15% margin of error. The spectrum of this star matches a stellar classification of B1.5 IV, which indicates this star has entered the subgiant stage and is in the process of evolving into a giant star. It is radiating around 10,000 times the luminosity of the Sun from its outer atmosphere at an effective temperature of 23,000 K, giving it a blue-white hue. This star has nearly 12 times the mass of the Sun and is roughly 15 million years old. Delta Lupi is a Beta Cephei variable star that undergoes periodic pulsations. It has a single period of variability las ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Lupi
Gamma Lupi, Latinized from γ Lupi, is a triple star system in the constellation of Lupus. It is easily visible to the naked eye, having an apparent magnitude of 2.77. It is also known in ancient Chinese astronomy as 騎官一 or "the 1st (star) of the Cavalry Officer". With a telescope, Gamma Lupi can be resolved into a binary star system in close orbit. This is known as the Gamma Lupi AB system, often abbreviated as γ Lupi AB or γ Lup AB. The system has a hierarchical architecture. The primary, Gamma Lupi A is itself a spectroscopic binary with an orbital period of 2.849769 days. Although the system does not show eclipses, the hotter star of the pair heats the side of the cooler star that faces it, and as they orbit each other the combined starlight varies in brightness by about 0.02 magnitudes, as seen from the Earth. The outer component, Gamma Lupi B, is widely-separated (125 astronomical units) and has an orbital period of 170 years. This star is a proper mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root (Chinese Constellation)
The Root mansion (氐宿, pinyin: Dī Xiù) is one of the twenty-eight mansions of the Chinese constellations. It is one of the eastern mansions of the Azure Dragon The Azure Dragon ( zh, c=青龍, p=Qīnglóng) is one of the Dragon King, Dragon Gods who represent the mount or Chthonic deities, chthonic forces of the Wufang Shangdi, Five Regions' Highest Deities (). It is also one of the Four Symbols o .... Asterisms {{DEFAULTSORT:Root (Chinese Constellation) Chinese constellations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Astronomy
Astronomy in China has a long history stretching from the Shang dynasty, being refined over a period of more than 3,000 years. The Ancient China, ancient Chinese people have identified stars from 1300 BCE, as Chinese star names later categorized in the twenty-eight mansions have been found on oracle bones unearthed at Anyang, dating back to the mid-Shang dynasty. The core of the "mansion" (宿 ''xiù'') system also took shape around this period, by the time of King Wu Ding (1250–1192 BCE). Detailed records of astronomical observations began during the Warring States period (fourth century BCE). They flourished during the Han period (202 BCE – 220 CE) and subsequent dynasties with the publication of star catalogues. Chinese astronomy was equatorial, centered on close observation of circumpolar stars, and was based on different principles from those in traditional Western astronomy, where heliacal risings and settings of zodiac constellations formed the basic ecliptic framew ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SN 1006
SN 1006 was a supernova that is likely the brightest observed stellar event in recorded history, reaching an estimated −7.5 visual magnitude, and exceeding roughly sixteen times the brightness of Venus. Appearing between April 30 and May 1, 1006, in the constellation of Lupus, this " guest star" was described by observers across China, Japan, modern-day Iraq, Egypt, and Europe, and was possibly recorded in North American petroglyphs. Some reports state it was clearly visible in the daytime. Modern astronomers now consider its distance from Earth to be about 7,200 light-years or 2,200 parsecs. Historic reports Egyptian astrologer and astronomer Ali ibn Ridwan, writing in a commentary on Ptolemy's ''Tetrabiblos'', stated that the "spectacle was a large circular body, 2 to 3 times as large as Venus. The sky was shining because of its light. The intensity of its light was a little more than a quarter that of Moon light" (or perhaps "than the light of the Moon when one-quar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Supernova Remnant
A supernova remnant (SNR) is the structure resulting from the explosion of a star in a supernova. The supernova remnant is bounded by an expanding shock wave, and consists of ejected material expanding from the explosion, and the interstellar material it sweeps up and shocks along the way. There are two common routes to a supernova: either a massive star may run out of fuel, ceasing to generate fusion energy in its core, and collapsing inward under the force of its own gravity to form a neutron star or a black hole; or a white dwarf star may accrete material from a companion star until it reaches a critical mass and undergoes a thermonuclear explosion. In either case, the resulting supernova explosion expels much or all of the stellar material with velocities as much as 10% the speed of light (or approximately 30,000 km/s) and a strong shock wave forms ahead of the ejecta. That heats the upstream plasma up to temperatures well above millions of K. The shock continuou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milliarcsecond
A minute of arc, arcminute (abbreviated as arcmin), arc minute, or minute arc, denoted by the symbol , is a unit of Angular unit, angular measurement equal to of a Degree (angle), degree. Since one degree is of a turn (geometry), turn, or complete rotation, one arcminute is of a turn. The nautical miles, nautical mile (nmi) was originally defined as the meridian arc, arc length of a minute of latitude on a spherical Earth, so the actual Earth's circumference is very near . A minute of arc is of a radian. A second of arc, arcsecond (abbreviated as arcsec), or arc second, denoted by the symbol , is a unit of Angular unit, angular measurement equal to of a minute of arc, of a degree, of a turn, and (about ) of a radian. These units originated in Babylonian astronomy as sexagesimal (base 60) subdivisions of the degree; they are used in fields that involve very small angles, such as astronomy, optometry, ophthalmology, optics, navigation, land surveying, and marksmanship. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
