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T Boötis
T Boötis is believed to have been a nova. It was observed by only one person, Joseph Baxendell on 9, 11 and 22 April 1860, but has not been seen since. It is located less than half a degree from Arcturus in the constellation Boötes and was at magnitude 9.75 when first seen, and magnitude 12.8 when last seen. Other astronomers, including Friedrich Winnecke, Edward Charles Pickering, Ernst Hartwig and Ernst Zinner looked for a star in this location without success. Despite being usually referred to as a nova, it had characteristics that set it apart from other novae - an amplitude of at least 7 magnitudes, an unusually rapid decline in brightness and a location unusually far from the Galactic plane. Joseph Ashbrook Joseph Ashbrook (April 4, 1918 – August 4, 1980) was an American astronomer. Life Ashbrook was born in Philadelphia, Pennsylvania. He received a doctorate from Harvard University in 1947 and taught at Yale University from 1946 to 1950, and at H ... suggest ... [...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 the positions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Celestial Reference System
The International Celestial Reference System (ICRS) is the current standard celestial reference system adopted by the International Astronomical Union (IAU). Its origin is at the barycenter of the Solar System, with axes that are intended to "show no global rotation with respect to a set of distant extragalactic objects". This fixed reference system differs from previous reference systems, which had been based on Catalogues of Fundamental Stars that had published the positions of stars based on direct "observations of heir equatorial coordinates, right ascension and declination" and had adopted as "privileged axes ... the mean equator and the dynamical equinox" at a particular date and time. The International Celestial Reference Frame (ICRF) is a realization of the International Celestial Reference System using reference celestial sources observed at radio wavelengths. In the context of the ICRS, a reference ''frame'' (RF) is the physical realization of a reference ''syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boötes (constellation)
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ' herdsman' or ' plowman' (literally, ' ox-driver'; from ''boûs'' ' cow'). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Boötis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. History and mythology In ancient Babylon, the stars of Boötes were known as SHU.PA. They were apparently depicted as the god Enlil, who was the leader of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nova
A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars. All observed novae involve white dwarfs in close binary systems. The main sub-classes of novae are classical novae, recurrent novae (RNe), and dwarf novae. They are all considered to be cataclysmic variable stars. Classical nova eruptions are the most common type. They are likely created in a close binary star system consisting of a white dwarf and either a main sequence, subgiant, or red giant star. When the orbital period falls in the range of several days to one day, the white dwarf is close enough to its companion star to start drawing accreted matter onto the surface of the white dwarf, which creates a dense but shallow atmosphere. This atmo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joseph Baxendell
Joseph Baxendell (1815–1887) was a British meteorologist and astronomer. Background He was the son of Thomas Baxendell and Mary his wife, née Shepley, and was born at Manchester on 19 April 1815. He received his early education at Thomas Whalley's school in Cheetham Hill, Manchester. He left school at the age of fourteen, but not before his natural love of science had been noticed and fostered by his mother and by his schoolmaster. He made good use of his powers of observation during six years spent at sea from his fourteenth to his twentieth year. In the Pacific he witnessed the shower of meteors in November 1833. When he abandoned seafaring life in 1835 he returned to Manchester, and for a while assisted his father, who was a land steward. Sutton, 1901 Career Baxendell afterwards had a business of his own as an estate agent. From the time of his return to Manchester he pursued, in a quiet unobtrusive way, his studies in astronomy and meteorology, in the former of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arcturus
, - bgcolor="#FFFAFA" , Note (category: variability): , , H and K emission vary. Arcturus is the brightest star in the northern constellation of Boötes. With an apparent visual magnitude of −0.05, it is the third-brightest of the individual stars in the night sky, and the brightest in the northern celestial hemisphere. The name Arcturus originated from ancient Greece; it was then cataloged as α Boötis by Johann Bayer in 1603, which is Latinized to Alpha Boötis. Arcturus forms one corner of the Spring Triangle asterism. Located relatively close at 36.7 light-years from the Sun, Arcturus is a single red giant of spectral type K1.5III—an aging star around 7.1 billion years old that has used up its core hydrogen and evolved off the main sequence. It is about the same mass as the Sun, but has expanded to 25 times its size and is around 170 times as luminous. Its diameter is 35 million kilometres. Thus far no companion has been detected. Nome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constellation
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellations likely go back to prehistory. People used them to relate stories of their beliefs, experiences, creation, or mythology. Different cultures and countries adopted their own constellations, some of which lasted into the early 20th century before today's constellations were internationally recognized. The recognition of constellations has changed significantly over time. Many changed in size or shape. Some became popular, only to drop into obscurity. Some were limited to a single culture or nation. The 48 traditional Western constellations are Greek. They are given in Aratus' work ''Phenomena'' and Ptolemy's ''Almagest'', though their origin probably predates these works by several centuries. Constellations in the far southern sky were ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boötes
Boötes ( ) is a constellation in the northern sky, located between 0° and +60° declination, and 13 and 16 hours of right ascension on the celestial sphere. The name comes from la, Boōtēs, which comes from grc-gre, Βοώτης, Boṓtēs ' herdsman' or ' plowman' (literally, ' ox-driver'; from ''boûs'' ' cow'). One of the 48 constellations described by the 2nd-century astronomer Ptolemy, Boötes is now one of the 88 modern constellations. It contains the fourth-brightest star in the night sky, the orange giant Arcturus. Epsilon Boötis, or Izar, is a colourful multiple star popular with amateur astronomers. Boötes is home to many other bright stars, including eight above the fourth magnitude and an additional 21 above the fifth magnitude, making a total of 29 stars easily visible to the naked eye. History and mythology In ancient Babylon, the stars of Boötes were known as SHU.PA. They were apparently depicted as the god Enlil, who was the leader of the Baby ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friedrich August Theodor Winnecke
Friedrich August Theodor Winnecke (February 5, 1835 in Groß-Heere, near Hannover – December 3, 1897 in Bonn) was a German astronomer. Winnecke worked at Pulkovo Observatory near Saint Petersburg from 1858 to 1865, but returned to Germany and served as professor of astronomy in Strasbourg from 1872 to 1881. He discovered or co-discovered a large number of comets, including the periodic comet 7P/Pons-Winnecke and the comet once known as "Pons-Coggia-Winnecke-Forbes" but later renamed to 27P/Crommelin after Andrew Crommelin, who computed its orbit. Winnecke also compiled a list of double stars, the Winnecke Catalogue of Double Stars, in 1869. He also found a number of nebulae. The asteroid 207 Hedda, discovered by Johann Palisa in 1879, was named after Winnecke's wife Hedwig. References External links * * F. Winnecke@ Astrophysics Data System The SAO/NASA Astrophysics Data System (ADS) is an online database of over 16 million astronomy and physics papers from bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Charles Pickering
Edward Charles Pickering (July 19, 1846 – February 3, 1919) was an American astronomer and physicist and the older brother of William Henry Pickering. Along with Carl Vogel, Pickering discovered the first spectroscopic binary stars. He wrote ''Elements of Physical Manipulations'' (2 vol., 1873–76). Personal life Pickering was born at 43 Bowdoin Street in Boston, Massachusetts, on July 19, 1846,Obituary, ''Boston Globe'', February 4, 1919 to a distinguished, cultivated family consisting of his brother, William Henry Pickering, father, Edward Pickering, and his mother, Charlotte Hammond. Edward's brother, William, was a graduate of MIT and professor of physics and astronomy. Edward was interested in the stars as a boy and constructed his own telescope by the age of 12. Pickering enjoyed his work at the observatory, but he was also enjoyed mountain climbing and bicycling in earlier days and later he was an interested spectator of football games. He was co-founder and first pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Hartwig
Carl Ernst Albrecht Hartwig (14 January 1851 in Frankfurt – 3 May 1923 in Bamberg) was a German astronomer. On 20 August 1885, Hartwig discovered a new star, SN 1885A (S Andromedae), in the Andromeda Galaxy, which was the first supernova that was ever seen that was outside the Milky Way. He is also credited for the discovery and co-discovery of three parabolic and hyperbolic comets, namely C/1879 Q2, C/1880 S1 and C/1886 T1. In 1882, Hartwig observed the transit of Venus in Argentina. During the 1883 observation campaign of comet 6P/d'Arrest he found five NGC objects working at the Strasbourg Observatory. In 1874 he became assistant at the Observatory of Strasbourg, 1884 astronomer at Dorpat Observatory and 1887 director of the Remeis Observatory at Bamberg. The French Academy of Sciences awarded him the Prix Valz in 1902 for his heliometer observations and work on variable stars. Lunar crater ''Hartwig'' and Martian crater ''Hartwig'' were both named in his hono ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ernst Zinner
Ernst Zinner (2 February 1886 in Goldberg, Silesia – 30 August 1970) was a German astronomer and noted historian of astronomy. After studies in Munich and Jena he obtained his PhD in 1907 at the University of Jena, followed by stays at the University of Lund, the University of Paris, and the Königstuhl Observatory in Heidelberg. From 1 February 1910, Zinner worked as an assistant at Remeis Observatory, Bamberg. Here, on 23 October 1913 he rediscovered the Comet Giacobini-Zinner, which had been previously discovered by Michel Giacobini in 1900. His main work during this time was on variable stars. After working as a meteorologist during World War I, Zinner returned to Bamberg, but then moved to Munich to work in geodesy. In 1924 Zinner received the professor's title from the University of Munich. He was appointed director of Remeis-Observatory in Bamberg, Germany, in 1926 and retired in 1956. During this time his main astronomical work centered on stellar astronomy. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
