|
Lambda Piscis Austrini
Lambda Piscis Austrini, Latinized from λ Piscis Austrini, is a solitary star in the southern constellation of Piscis Austrinus. It has a blue-white hue and is visible to the naked eye with an apparent visual magnitude of +5.42. Based upon an annual parallax shift of 6.51 mas as measured from Earth, it is located around 500 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.16 due to interstellar dust. This is a B-type main sequence star with a stellar classification of B7 V. It has an estimated 3.58 times the mass of the Sun and about 4.2 times the Sun's radius. The star is spinning with a projected rotational velocity of 50 km/s and is 76% of the way through its main sequence lifetime. It is radiating 249 times the solar luminosity from its photosphere at an effective temperature of 12,023 K. Lambda Piscis Austrini is moving through the Galaxy at a speed of 18.1&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 surface. The rotation of a star produces an equatorial bulge due to centrifugal force. As stars are not solid bodies, they can also undergo differential rotation. Thus the equator of the star can rotate at a different angular velocity than the higher latitudes. These differences in the rate of rotation within a star may have a significant role in the generation of a stellar magnetic field. The magnetic field of a star interacts with the stellar wind. As the wind moves away from the star its rate of angular velocity slows. The magnetic field of the star interacts with the wind, which applies a drag to the stellar rotation. As a result, angular momentum is transferred from the star to the wind, and over time this gradually slows the star's rate of rotation. Measurement Unless a star is being obse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epsilon Piscis Austrini
Epsilon Piscis Austrini, Latinized from ε Piscis Austrini, is a blue-white hued star in the southern constellation of Piscis Austrinus. It is visible to the naked eye with an apparent visual magnitude of +4.17. Based upon an annual parallax shift of 8.0981 ± 0.3582 mas as seen from the GAIA satellite, the system is located roughly 400 light years from the Sun. This is a B-type main sequence star with a stellar classification of B8 Ve. It is a Be star that is spinning rapidly with a projected rotational velocity of 216 km/s, compared to an equatorial critical velocity of 301 km/s. The star has 4.1 times the mass of the Sun and is radiating 661 times the solar luminosity from its photosphere at an effective temperature of 11,066 K. Epsilon Piscis Austrini is moving through the Galaxy at a speed of 18.7 km/s relative to the Sun. Its projected Galactic orbit carries it between and from the center of the Galaxy. Naming In Chinese, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
49 Aquarii
49 Aquarii, abbreviated 49 Aqr, is a star in the zodiac constellation of Aquarius. ''49 Aquarii'' is its Flamsteed designation. It is a dim star with an apparent visual magnitude of 5.53. The distance to 49 Aqr, as determined from its annual parallax shift of , is 266 light years. It is moving closer to the Earth with a heliocentric radial velocity of −13 km/s. This is an aging K-type giant star with a stellar classification of . It shows a spectral anomaly with the absorption lines of cyanogen (CN). This is a red clump giant, indicating that it is generating energy through the helium fusion at its core. It is around 950 million years old with 2.2 times the mass of the Sun and has expanded to nine times the Sun's radius. It is radiating 50 times the Sun's luminosity from its enlarged photosphere at an effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amoun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
47 Aquarii
47 Aquarii, abbreviated 47 Aqr, is a star in the zodiac constellation of Aquarius. ''47 Aquarii'' is its Flamsteed designation. It is a faint star but visible to the naked eye in good seeing conditions, having an apparent visual magnitude of 5.135. Based upon an annual parallax shift of , it is located 181 light years away. At that distance, the visual magnitude of the star is diminished by an extinction of 0.088 due to interstellar dust. It is moving further from the Earth with a heliocentric radial velocity of +48 km/s. This is an evolved giant star currently on the red giant branch with a stellar classification of K0 III. The star has 1.35 times the mass of the Sun and has expanded to 7.86 times the Sun's radius. It is radiating 30 times the Sun's luminosity from its enlarged photosphere at an effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
41 Aquarii
41 Aquarii is a double star in the equatorial constellation of Aquarius. ''41 Aquarii'' is its Flamsteed designation. It is visible to the naked eye as a dim, orange-hued point of light with a combined apparent visual magnitude of 5.354. The pair are located at a distance of around from the Sun based on parallax, but are drifting closer with a radial velocity of –25 km/s. The brighter component of the pair is a red clump giant star with a stellar classification of K0 III and a magnitude of 5.73. This is an aging star that has exhausted the supply of hydrogen at its core and is now generating energy through core helium fusion. It has eight times the girth of the Sun and is radiating 34 times the luminosity of the Sun at an effective temperature of 4,750 K. At an angular separation of 5.148 arcseconds, the fainter companion is an F-type main sequence star An F-type main-sequence star (F V) is a main-sequence, hydrogen-fusing star of spectral type F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
35 Aquarii
35 Aquarii is a single star located roughly 2,200 light years away from the Sun in the zodiac constellation of Aquarius. ''35 Aquarii'' is its Flamsteed designation. It is visible to the naked eye as a dim, blue-white hued star with an apparent visual magnitude of 5.80. This object is moving closer to the Earth with a heliocentric radial velocity of −7 km/s, and is a suspected runaway star that may have been ejected from an open cluster as the result of a binary–binary interaction. This is a blue giant star with a stellar classification of B2 III;, a massive star that has evolved off the main sequence. It is around 22.5 million years old with a relatively low projected rotational velocity of 10 km/s. The star has 10 times the mass of the Sun and is radiating 1,622 times the Sun's luminosity from its photosphere at an effective temperature The effective temperature of a body such as a star or planet is the temperature of a black body that would ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
29 Aquarii
29 Aquarii is a binary star system located around 590 light years away from the Sun in the equatorial constellation of Aquarius. ''29 Aquarii'' is the Flamsteed designation; the system also bears the variable star designation DX Aquarii. It is a challenge to view with the naked eye, appearing as a dim star with a combined apparent visual magnitude of 6.39. The system is moving further from the Earth with a heliocentric radial velocity of about +15 km/s. This is a spectroscopic binary system with a close circular orbit taking just 0.945 days to complete. Despite their proximity, this does not appear to be a contact binary system. The orbital plane of the two stars lies near the line of sight, so they form an Algol-type eclipsing binary. The first component of the system is an A-type main sequence star with a stellar classification of A2 V. Its companion is giant star with a classification of K0 III. The variability of this system was first notice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Encampment (Chinese Constellation)
The Encampment mansion () is one of the 28 mansions of the Chinese constellations. It is one of the northern mansions of the Black Tortoise The Black Tortoise () is one of the Four Symbols of the Chinese constellations. Despite its English name, it is usually depicted as a tortoise entwined together with a snake. The name used in East Asian languages does not mention either anima .... Asterisms References {{DEFAULTSORT:Encampment (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 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) and flourished from the Han period onward. 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 framework. Joseph Needham has described the ancient Chinese as the most persistent and accurate obser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known. When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less than that of a black body), the actual temperature of the body will be higher than the effective temperature. The net emissivity may be low due to surface or atmospheric properties, including greenhouse effect. Star The effective temperature of a star is the temperature of a black body with the same luminosity per ''surface area'' () as the star and is defined according to the Stefan–Boltzmann law . Notice that the total (bolometric) luminosity of a star is then , where is the stellar radius. The definition of the stellar radius is obviously not straightf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
