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Grigory Shajn
Grigory Abramovich Shajn (russian: Григорий Абрамович Шайн) (April 19, 1892 – August 4, 1956) was a Soviet/Russian astronomer. In modern English transliteration, his surname would be given as Shayn, but his astronomical discoveries are credited under the name G. Shajn. Nonetheless, his last name is sometimes given as Schayn. He earned a masters degree from Tomsk University in 1920. He was the husband of Pelageya Shajn (Пелагея Фёдоровна Шайн) née Sannikova (Санникова), who was also a Russian astronomer. He worked on stellar spectroscopy and the physics of gaseous nebulas. Together with Otto Struve, he studied the rapid rotation of stars of young spectral types and measured the radial velocities of stars. He discovered new gaseous nebulas and the anomalous abundance of 13C in stellar atmospheres. He became a member of the Soviet Academy of Sciences in 1939, and was also a member of various foreign societies such as the Roy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. Of the roughly one million known asteroids the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 AU from the Sun, in the main asteroid belt. Asteroids are generally classified to be of three types: C-type, M-type, and S-type. These were named after and are generally identified with carbonaceous, metallic, and silicaceous compositions, respectively. The size of asteroids varies greatly; the largest, Ceres, is almost across and qualifies as a dwarf planet. The total mass of all the asteroids combined is only 3% that of Earth's Moon. The majority of main belt asteroids follow slightly elliptical, stable orbits, revolving in the same direction as the Earth and taking from three to six years to comple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radial Velocity
The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is equivalent to the vector projection of the target-observer relative velocity onto the relative direction (geometry), relative direction connecting the two points. In astronomy, the point is usually taken to be the observer on Earth, so the radial velocity then denotes the speed with which the object moves away from the Earth (or approaches it, for a negative radial velocity). Formulation Given a differentiable vector \mathbf \in \mathbb^3 defining the instantaneous position of a target relative to an observer. Let with \mathbf \in \mathbb^3, the instantaneous velocity of the target with respect to the observer. The magnitude of the position vector \mathbf is defined as The quantity range rate is the time derivative of the magnitud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jewish Astronomers
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The people of the Kingdom of Israel and the ethnic and religious group known as the Jewish people that descended from them have been subjected to a number of forced migrations in their history" and Hebrews of historical Israel and Judah. Jewish ethnicity, nationhood, and religion are strongly interrelated, "Historically, the religious and ethnic dimensions of Jewish identity have been closely interwoven. In fact, so closely bound are they, that the traditional Jewish lexicon hardly distinguishes between the two concepts. Jewish religious practice, by definition, was observed exclusively by the Jewish people, and notions of Jewish peoplehood, nation, and community were suffused with faith in the Jewish God, the practice of Jewish (religious) la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1956 Deaths
Events January * January 1 – The Anglo-Egyptian Sudan, Anglo-Egyptian Condominium ends in Sudan. * January 8 – Operation Auca: Five U.S. evangelical Christian Missionary, missionaries, Nate Saint, Roger Youderian, Ed McCully, Jim Elliot and Pete Fleming, are killed for trespassing by the Huaorani people of Ecuador, shortly after making contact with them. * January 16 – Egyptian leader Gamal Abdel Nasser vows to reconquer Palestine (region), Palestine. * January 25–January 26, 26 – Finnish troops reoccupy Porkkala, after Soviet Union, Soviet troops vacate its military base. Civilians can return February 4. * January 26 – The 1956 Winter Olympics open in Cortina d'Ampezzo, Italy. February * February 11 – British Espionage, spies Guy Burgess and Donald Maclean (spy), Donald Maclean resurface in the Soviet Union, after being missing for 5 years. * February 14–February 25, 25 – The 20th Congress of the Communist Party of the Soviet Union is held in Mosc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1892 Births
Year 189 ( CLXXXIX) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Silanus and Silanus (or, less frequently, year 942 ''Ab urbe condita''). The denomination 189 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years. Events By place Roman Empire * Plague (possibly smallpox) kills as many as 2,000 people per day in Rome. Farmers are unable to harvest their crops, and food shortages bring riots in the city. China * Liu Bian succeeds Emperor Ling, as Chinese emperor of the Han Dynasty. * Dong Zhuo has Liu Bian deposed, and installs Emperor Xian as emperor. * Two thousand eunuchs in the palace are slaughtered in a violent purge in Luoyang, the capital of Han. By topic Arts and sciences * Galen publishes his ''"Treatise on the various temperaments"'' (aka ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monthly Notices Of The Royal Astronomical Society
''Monthly Notices of the Royal Astronomical Society'' (MNRAS) is a peer-reviewed scientific journal covering research in astronomy and astrophysics. It has been in continuous existence since 1827 and publishes letters and papers reporting original research in relevant fields. Despite the name, the journal is no longer monthly, nor does it carry the notices of the Royal Astronomical Society. History The first issue of MNRAS was published on 9 February 1827 as ''Monthly Notices of the Astronomical Society of London'' and it has been in continuous publication ever since. It took its current name from the second volume, after the Astronomical Society of London became the Royal Astronomical Society (RAS). Until 1960 it carried the monthly notices of the RAS, at which time these were transferred to the newly established ''Quarterly Journal of the Royal Astronomical Society'' (1960–1996) and then to its successor journal ''Astronomy & Geophysics'' (since 1997). Until 1965, MNRAS ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1648 Shajna
1648 Shajna, provisional designation , is a stony asteroid from the inner regions of the asteroid belt, approximately 9 kilometers in diameter. It was discovered on 5 September 1935, by Russian astronomer Pelageya Shajn at Simeiz Observatory on the Crimean peninsula. Two weeks later, it was independently discovered by Cyril Jackson at Johannesburg Observatory, South Africa. It was later named after the discoverer and her husband, Russian astronomers Grigory Shajn. Orbit and classification ''Shajna'' orbits the Sun in the inner main-belt at a distance of 1.8–2.7 AU once every 3 years and 4 months (1,221 days). Its well-determined orbit has an eccentricity of 0.21 and an inclination of 5 ° with respect to the ecliptic. In 1921, ''Shajna'' was first identified as at Heidelberg Observatory. Its first used observation was taken at Uccle in 1934, when it was identified as , extending the body's observation arc by one year prior to its official discovery observation. Rota ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shayn (crater)
Shayn is an eroded impact crater that lies on the Moon's far side. It lies to the north of the crater Freundlich and northeast of Trumpler. To the west of Shayn is the crater Nušl, and to the north-northeast lies Champollion. This is an eroded crater that has undergone wear from subsequent impacts. Most of the rim has become rounded and the original sharp edges lost from a history of minor impacts. The southern inner wall, however, still displays some slumped, shelf-like structure. A pair of small impacts lie along the inner wall in the northeast part of the crater. The interior floor is pitted with small and tiny craterlets. The most notable of these is a small crater to the northwest of the midpoint. Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Shayn. See also * 1648 Shajna 1648 Shajna, provisional designation , is a stony asteroid from the inner regions of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
61P/Shajn–Schaldach
61P/Shajn–Schaldach is a periodic comet in the Solar System with a current orbital period of 7.49 years. It was discovered on 18 September 1949 on a photographic plate by Pelageja F. Shajn at the Simeiz Observatory, Crimea, part of the Crimean Astrophysical Observatory. It was also discovered independently two days later by Robert D. Schaldach at the Lowell Observatory in Arizona, US, also on a photographic plate. Shajn then found evidence of the comet on earlier photographs taken on August 28 and September 4. The first computations of the comet's orbit gave a perihelion date of between December 1949 and October 1950 with a periodicity of 7.76 years. After taking into account perturbations due a close approach to Jupiter the next perihelion was calculated to be on 15 March 1957 but in that year it was never found. It was also not discovered on its next predicted appearance in 1964. The most likely explanation for the two failures was the comet's faintness. It was, however, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C/1925 F1
This is a list of parabolic and hyperbolic comets in the Solar System. Many of these comets may come from the Oort cloud, or perhaps even have interstellar origin. The Oort Cloud is not gravitationally attracted enough to the Sun to form into a fairly thin disk, like the inner Solar System. Thus, comets originating from the Oort Cloud can come from roughly any orientation (inclination to the ecliptic), and many even have a retrograde orbit. By definition, a hyperbolic orbit means that the comet will only travel through the Solar System once, with the Sun acting as a gravitational slingshot, sending the comet hurtling out of the Solar System entirely unless its eccentricity is otherwise changed. Comets orbiting in this way still originate from the Solar System, however. Typically comets in the Oort Cloud are thought to have roughly circular orbits around the Sun, but their orbital velocity is so slow that they may easily be perturbed by passing stars and the galactic tide. Astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently bright, a comet may be seen from Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions. Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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