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Beta Delphini
Beta Delphini (β Delphini, abbreviated Beta Del, β Del) is a binary star in the constellation of Delphinus. It is the brightest star in Delphinus. The two components of the system are designated Beta Delphini A (officially named Rotanev , which is historically the name of the system) and B. Nomenclature ''β Delphini'' ( Latinised to ''Beta Delphini'') is the binary's Bayer designation. The designations of the two components as ''Beta Delphini 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). Beta Delphini bore an historical name, ''Rotanev'', which arose as follows: Niccolò Cacciatore was the assistant to Giuseppe Piazzi, and later his successor as Director of the Palermo Observatory. The name first appeared in Piazzi's Palermo Star Catalogue. When the Catalogue was published in 1814, the unfamiliar n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a instant, moment in time used as a reference point for some time-varying astronomical quantity. It is useful for the celestial coordinates or orbital elements of a Astronomical object, celestial body, as they are subject to Perturbation (astronomy), perturbations and vary with time. These time-varying astronomical quantities might include, for example, the mean longitude or mean anomaly of a body, the node of its orbit relative to a reference plane, the direction of the apogee or Perihelion and aphelion, aphelion of its orbit, or the size of the major axis of its orbit. The main use of astronomical quantities specified in this way is to calculate other relevant parameters of motion, in order to predict future positions and velocities. The applied tools of the disciplines of celestial mechanics or its subfield orbital mechanics (for predicting orbital paths and positions for bodies in motion under the gravitational effects of other bodi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palermo Astronomical Observatory
The Giuseppe S. Vaiana Astronomical Observatory is an astronomical observatory located in Palermo, Sicily, Italy, housed inside the Palazzo dei Normanni. It is one of the research facilities of the National Institute of Astrophysics. The observatory carries out research projects in the field of astronomy and astrophysics including the study of solar and stellar coronas, stellar evolution (including the birth of stars) and of the supernova remnants. History It was founded in 1790 by Ferdinand I of the Two Sicilies, at the suggestion of some intellectuals of the time, including the then Sicilian viceroy Francesco d'Aquino, Prince of Caramanico to endow the Sicilian city with an element of prestige as an astronomical observatory. It was hard to find an expert astronomer who would agree to work in such a peripheral location at the time. In the end the choice fell on Giuseppe Piazzi, a middle-aged mathematician, who before had not particularly distinguished himself in astronomy. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Classification
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grating into a spectrum exhibiting the Continuum (spectrum), rainbow of colors interspersed with spectral lines. Each line indicates a particular chemical element or molecule, with the line strength indicating the abundance of that element. The strengths of the different spectral lines vary mainly due to the temperature of the photosphere, although in some cases there are true abundance differences. The ''spectral class'' of a star is a short code primarily summarizing the ionization state, giving an objective measure of the photosphere's temperature. Most stars are currently classified under the Morgan–Keenan (MK) system using the letters ''O'', ''B'', ''A'', ''F'', ''G'', ''K'', and ''M'', a sequence from the hottest (''O'' type) to the coo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sherburne Wesley Burnham
Sherburne Wesley Burnham (December 12, 1838 – March 11, 1921) was an American astronomer. For more than 50 years Burnham spent all his free time observing the heavens, mainly concerning himself with binary stars. Biography Sherburne Wesley Burnham was born in Thetford, Vermont. His parents were Roswell O. Burnham and Marinda (née Foote) Burnham. He graduated from the academy in Thetford, and that was the extent of his schooling. He taught himself shorthand, and by 1858 was in New York City. Burnham was a reporter for the Union Army in New Orleans during the Civil War. While in New Orleans, he bought a copy of a popular book ''Geography of the Heavens'', which piqued his interest in astronomy. After the war, he moved to Chicago and worked as a court reporter for over 20 years. At night Burnham was an amateur astronomer, except for four years (1888–1892) he worked as a professional astronomer at Lick Observatory. He left court reporting in 1902, but remained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zeta Delphini
Zeta Delphini (ζ Delphini) is a star in the constellation of Delphinus. With an apparent magnitude of about 4.6, it is faintly visible to the naked eye. Parallax measurements of the system made by the Hipparcos spacecraft put it at a distance of about 220 light-years, or 67 parsecs. Zeta Delphini has a spectral type of A3V, implying it is an A-type main-sequence star. These types of stars are bluish-white colored, and have effective temperatures between 7100 and 11500 K: Zeta Delphini has a temperature of 8336 K. Its age is estimated to be around 500 million years, considerably younger than the Sun. In 2014, the discovery of a brown dwarf around Zeta Delphini was announced. Zeta Delphini B is a brown dwarf with a spectral type of L5 (but may be from L3 to L7), and has a mass of about 55 Jupiter Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a gas giant with a mass more than two and a half times that of all the other p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta Delphini
Delta Delphini, Latinized from δ Delphini, is a binary star in the northern constellation of Delphinus. It is visible to the naked eye with an apparent visual magnitude of 4.43. Based upon an annual parallax shift of 14.61 mas as seen from the Earth, the system is located about 223 light years from the Sun. This is a double-lined spectroscopic binary system with an orbital period of 40.58 days. The two components are nearly identical chemically peculiar stars, having a combined stellar classification of kA7hF1VmF1pSrEuCr:. This notation indicates the calcium K line matches an A7 star, the hydrogen lines an F1 star, and the metal lines an F1 star, with particularly strong lines of strontium, europium, and chromium. Each of the stars is a Delta Scuti variable, with the system having a dominant period of 0.1568 days and an amplitude of 0.0700 in magnitude. Delta Delphini forms the prototype of a class of metal- lined δ Scuti subgiant or giant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma2 Delphini
Gamma Delphini, which is Latinized from γ Delphini, is a wide binary star system in the northern constellation of Delphinus. The star marks one corner of the asterism " Job's Coffin". The pair can be split with a modest amateur telescope and have been described as "one of the prettier pairs in the sky", with their contrasting colors said to be orange and lime in appearance. Together, the system is visible to the naked eye with a combined apparent visual magnitude of 3.87. Space motion The system is located at a distance of 115 light years from the Sun based on parallax, but is drifting closer with a radial velocity of −7 km/s. It is a member of the thin disk population, and is a proposed member of the Wolf 630 moving group. This star was found to be a double by Christian Mayer and later observed by William Herschel on Sept 27th, 1779. It was later included as STF 2727 in the catalogue compiled by F. G. W. Struve and can be found under this name in ... [...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] |
Girl (Chinese Constellation)
The Girl mansion (女宿, pinyin: Nǚ Xiù) is one of the Twenty-eight 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 Notes {{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] |
Multiple Star
A star system or stellar system is a small number of stars that orbit each other, bound by gravitational attraction. A large group of stars bound by gravitation is generally called a ''star cluster'' or ''galaxy'', although, broadly speaking, they are also star systems. Star systems are not to be confused with planetary systems, which include planets and similar bodies (such as comets). A star system of two stars is known as a ''binary star'', ''binary star system'' or ''physical double star''. If there are no tidal effects, no perturbation from other forces, and no transfer of mass from one star to the other, such a system is stable, and both stars will trace out an elliptical orbit around the barycenter of the system indefinitely. ''(See Two-body problem)''. Examples of binary systems are Sirius, Procyon and Cygnus X-1, the last of which probably consists of a star and a black hole. Multiple star systems A multiple star system consists of three or more stars that appear f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IAU Working Group On Star Names
The International Astronomical Union (IAU) established a Working Group on Star Names (WGSN) in May 2016 to catalog and standardize proper names for stars for the international astronomical community. It operates under Division C – Education, Outreach and Heritage. The IAU states that it is keen to make a distinction between the terms ''name'' and ''designation''. To the IAU, ''name'' refers to the (usually colloquial) term used for a star in everyday conversation, while ''designation'' is solely alphanumerical, and used almost exclusively in official catalogues and for professional astronomy. (The WGSN notes that transliterated Bayer designations (e.g., Tau Ceti) are considered a special historical case and are treated as designations.) Terms of reference The terms of reference for the WGSN for the period 2016–2018 were approved by the IAU Executive Committee at its meeting on 6 May 2016. In summary, these are to: * establish IAU guidelines for the proposal and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
