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ρ Ophiuchi
Rho Ophiuchi (ρ Ophiuchi) is a star system, multiple star system in the constellation Ophiuchus. The central system has an apparent magnitude of 4.63. Based on the central system's stellar parallax, parallax, it is located about 450 light-years distant. The other stars in the system are slightly farther away. System The central system is known as Rho Ophiuchi AB. It consists of three blue-colored subgiants or main-sequence stars, designated Rho Ophiuchi Aa, Ab and B, respectively. Rho Ophiuchi Aa-Ab is a spectroscopic binary with an orbital period of 88 days and an orbital period of 1.1 astronomical units. Farther away is the B companion, a visual binary whose sky-projected distance from the inner pair appears to be 3.1″, corresponding to a separation of at least 344 AU. However, the actual separation is larger, and the two take about 2,400 years to complete an orbit. The two stars dominate the radiation field around the Rho Ophiuchi cloud complex. Rho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
J2000
In astronomy, an epoch or reference epoch is a 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 celestial body, as they are subject to 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 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 bodies) can be used to generate an ephemeris, a table of values giving ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Period
In astronomy, the rotation period or spin period of a celestial object (e.g., star, planet, moon, asteroid) has two definitions. The first one corresponds to the '' sidereal rotation period'' (or ''sidereal day''), i.e., the time that the object takes to complete a full rotation around its axis relative to the background stars ( inertial space). The other type of commonly used "rotation period" is the object's '' synodic rotation period'' (or ''solar day''), which may differ, by a fraction of a rotation or more than one rotation, to accommodate the portion of the object's orbital period around a star or another body during one day. Measuring rotation For solid objects, such as rocky planets and asteroids, the rotation period is a single value. For gaseous or fluid bodies, such as stars and giant planets, the period of rotation varies from the object's equator to its pole due to a phenomenon called differential rotation. Typically, the stated rotation period for a giant pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Henry Draper Catalogue Objects
Henry may refer to: People and fictional characters * Henry (given name), including lists of people and fictional characters * Henry (surname) * Henry, a stage name of François-Louis Henry (1786–1855), French baritone Arts and entertainment * Henry (2011 film), ''Henry'' (2011 film), a Canadian short film * Henry (2015 film), ''Henry'' (2015 film), a virtual reality film * ''Henry: Portrait of a Serial Killer'', a 1986 American crime film * Henry (comics), ''Henry'' (comics), an American comic strip created in 1932 by Carl Anderson * "Henry", a song by New Riders of the Purple Sage Places Antarctica * Henry Bay, Wilkes Land Australia *Henry River (New South Wales) *Henry River (Western Australia) Canada * Henry Lake (Vancouver Island), British Columbia * Henry Lake (Halifax County), Nova Scotia * Henry Lake (District of Chester), Nova Scotia New Zealand * Lake Henry (New Zealand) * Henry River (New Zealand) United States * Henry, Illinois * Henry, Indiana * Henry, Nebras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durchmusterung Objects
In astronomy, Durchmusterung or Bonner Durchmusterung (BD) is an astrometric star catalogue of the whole sky, published by the Bonn Observatory in Germany from 1859 to 1863, with an extension published in Bonn in 1886. The name comes from ('run-through examination'), a German word used for a systematic survey of objects or data. The term has sometimes been used for other astronomical surveys, including not only stars, but also the search for other celestial objects. Special tasks include celestial scanning in electromagnetic spectrum, electromagnetic wavelengths shorter or longer than visible light waves. Original catalog The Bonner Durchmusterung (abbreviated BD), was initiated by Friedrich Wilhelm Argelander, Friedrich Argelander and using observations largely carried out by his assistants, which resulted in a catalogue of the positions and apparent magnitudes of 342,198 stars down to approximate apparent magnitude 9.5 and covering the sky from 90°N to 2°S declination. The cat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flamsteed Objects
John Flamsteed (19 August 1646 – 31 December 1719) was an English astronomer and the first Astronomer Royal. His main achievements were the preparation of a 3,000-star catalogue, ''Catalogus Britannicus'', and a star atlas called '' Atlas Coelestis'', both published posthumously. He also made the first recorded observations of Uranus, although he mistakenly catalogued it as a star, and he laid the foundation stone for the Royal Greenwich Observatory. Life Flamsteed was born in Denby, Derbyshire, England, the only son of Stephen Flamsteed and his first wife, Mary Spadman. He was educated at the free school of Derby and at Derby School, in St Peter's Churchyard, Derby, near where his father carried on a malting business. At that time, most masters of the school were Puritans. Flamsteed had a solid knowledge of Latin, essential for reading the scientific literature of the day, and a love of history, leaving the school in May 1662.Birks, John L. (1999) ''John Flamsteed, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bayer Objects
Bayer AG (English: , commonly pronounced ; ) is a German multinational pharmaceutical and biotechnology company and is one of the largest pharmaceutical companies and biomedical companies in the world. Headquartered in Leverkusen, Bayer's areas of business include: pharmaceuticals, consumer healthcare products, agricultural chemicals, seeds and biotechnology products. The company is a component of the EURO STOXX 50 stock market index. Bayer was founded in 1863 in Barmen as a partnership between dye salesman Friedrich Bayer (1825–1880) and dyer Friedrich Weskott (1821–1876). The company was established as a dyestuffs producer, but the versatility of aniline chemistry led Bayer to expand its business into other areas. In 1899, Bayer launched the compound acetylsalicylic acid under the trademarked name Aspirin. Aspirin is on the World Health Organization's List of Essential Medicines. In 2021, it was the 34th most commonly prescribed medication in the United State ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-type Main-sequence Stars
A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars are extremely luminous and blue. Their spectra have strong neutral helium absorption lines, which are most prominent at the B2 subclass, and moderately strong hydrogen lines. Examples include Regulus, Algol A and Acrux. History This class of stars was introduced with the Harvard sequence of stellar spectra and published in the ''Revised Harvard photometry'' catalogue. The definition of type B-type stars was the presence of non-ionized helium lines with the absence of singly ionized helium in the blue-violet portion of the spectrum. All of the spectral classes, including the B type, were subdivided with a numerical suffix that indicated the degree to which they approached the next classification. Thus B2 is 1/5 of the way from type B (or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Star Systems
A star system or stellar system is a small number of stars that orbit each other, bound by gravity, gravitational attraction. It may sometimes be used to refer to a single star. 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). Terminology A star system of two stars is known as a ''binary star'', ''binary star system'' or ''physical double star''. Systems with four or more components are rare, and are much less commonly found than those with 2 or 3. Multiple-star systems are called ''triple'', ''ternary'', or ''trinary'' if they contain three stars; ''quadruple'' or ''quaternary'' if they contain four stars; ''quintuple'' or ''quintenary'' with five stars; ''sextuple'' or ''sextenary'' with six stars; ''septuple'' or ''septenary'' with seven stars; and ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnitude (astronomy)
In astronomy, magnitude is a measure of the brightness of an astronomical object, object, usually in a defined passband. An imprecise but systematic determination of the magnitude of objects was introduced in ancient times by Hipparchus. Magnitude values do not have a unit. The scale is Logarithmic scale, logarithmic and defined such that a magnitude 1 star is exactly 100 times brighter than a magnitude 6 star. Thus each step of one magnitude is \sqrt[5] \approx 2.512 times brighter than the magnitude 1 higher. The brighter an object appears, the lower the value of its magnitude, with the brightest objects reaching negative values. Astronomers use two different definitions of magnitude: apparent magnitude and absolute magnitude. The ''apparent'' magnitude () is the brightness of an object and depends on an object's intrinsic luminosity, its Cosmic distance ladder, distance, and the Extinction (astronomy), extinction reducing its brightness. The ''absolute'' magnitude () describes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinction (astronomy)
In astronomy, extinction is the absorption (electromagnetic radiation), absorption and light scattering, scattering of electromagnetic radiation by dust and gas between an emitting astronomical object and the observation, observer. Interstellar extinction was first documented as such in 1930 by Robert Julius Trumpler. However, its effects had been noted in 1847 by Friedrich Georg Wilhelm von Struve, and its effect on the colors of stars had been observed by a number of individuals who did not connect it with the general presence of Cosmic dust, galactic dust. For stars lying near the plane of the Milky Way which are within a few thousand parsecs of the Earth, extinction in the visual band of frequencies (photometric system) is roughly 1.8 Magnitude (astronomy), magnitudes per kiloparsec. For Observatory#Ground-based_observatories, Earth-bound observers, extinction arises both from the interstellar medium and the Atmosphere of Earth, Earth's atmosphere; it may also arise fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rho Ophiuchi Cloud Complex
The Rho Ophiuchi cloud complex is a complex of interstellar clouds with different nebulae, particularly a dark nebula which is centered 1° south of the star ρ Ophiuchi, which it among others extends to, of the constellation Ophiuchus. At an estimated distance of about , or 460 light years, it is one of the closest Star formation, star-forming regions to the Solar System. Cloud complex This cloud covers an angular area of on the celestial sphere. It consists of two major regions of dense gas and dust. The first contains a star-forming cloud (L1688) and two filaments (L1709 and L1755), while the second has a star-forming region (L1689) and a filament (L1712–L1729). These filaments extend up to 10–17.5 parsecs in length and can be as narrow as 0.24 parsecs in width. The large extensions of the complex are also called ''Dark River'' clouds (or ''Rho Ophiuchi Streamers'') and are identified as Barnard Catalogue, Barnard 44 and 45. Some of the structures within the complex appear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-type Main-sequence Star
A B-type main-sequence star (B V) is a main-sequence (hydrogen-burning) star of spectral type B and luminosity class V. These stars have from 2 to 16 times the mass of the Sun and surface temperatures between 10,000 and 30,000 K. B-type stars are extremely luminous and blue. Their spectra have strong neutral helium absorption lines, which are most prominent at the B2 subclass, and moderately strong hydrogen lines. Examples include Regulus, Algol A and Acrux. History This class of stars was introduced with the Harvard sequence of stellar spectra and published in the ''Revised Harvard photometry'' catalogue. The definition of type B-type stars was the presence of non-ionized helium lines with the absence of singly ionized helium in the blue-violet portion of the spectrum. All of the spectral classes, including the B type, were subdivided with a numerical suffix that indicated the degree to which they approached the next classification. Thus B2 is 1/5 of the way from type B (or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
