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Johann Heinrich Von Mädler
Johann Heinrich von Mädler (29 May 1794, Berlin – 14 March 1874, Hannover) was a German astronomer. Life and work His father was a master tailor and when 12 he studied at the Friedrich‐Werdersche Gymnasium in Berlin. He was orphaned at age 19 by an outbreak of typhus, and found himself responsible for raising three younger sisters. He began giving academic lessons as a private tutor and in this way met Wilhelm Beer, a wealthy banker, in 1824. In 1829 Beer decided to set up a private observatory in Berlin, with a 95 mm refractor telescope made by Joseph von Fraunhofer, and Mädler worked there. In 1830 they began producing drawings of Mars which later became the first true maps of that planet. They were the first to choose what is today known as Sinus Meridiani as the prime meridian for Martian maps. They made a preliminary determination for Mars's rotation period, which was off by almost 13 seconds. A later determination in 1837 was off by only 1.1 seconds. They a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy
Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include planets, natural satellite, moons, stars, nebulae, galaxy, galaxies, meteoroids, asteroids, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond atmosphere of Earth, Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Egyptian astronomy, Egyptians, Babylonian astronomy, Babylonians, Greek astronomy, Greeks, Indian astronomy, Indians, Chinese astronomy, Chinese, Maya civilization, M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tartu Observatory
The Tartu Observatory () is the largest astronomy, astronomical observatory in Estonia. On 1 January 2018, Tartu Observatory was joined again to the University of Tartu, and the observatory is now an institute of the university. It is located on the Tõravere hill, about 20 km south-west of Tartu in Nõo Parish, Tartu County. The University of Tartu Old Observatory, old Tartu Observatory, located in Tartu city centre, is known internationally for its connection to Friedrich Georg Wilhelm von Struve and the Struve Geodetic Arc, of which it is the first reference point. History The Tartu Observatory was founded at the University of Tartu, Imperial University of Dorpat as it was reopened in 1802. The observatory building was completed in 1810 on the Toome hill in Dorpat. The instruments were installed in 1814 by von Struve who subsequently started observations. In 1824, a 9" Joseph von Fraunhofer, Fraunhofer refractor arrived, the largest achromatic telescope in the world at t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mädler (lunar Crater)
Mädler is a lunar impact crater located on the mare that joins Sinus Asperitatis in the north to Mare Nectaris to the southeast. To the west is the prominent crater Theophilus, and Mädler lies amidst the outer rampart Rampart may refer to: * Rampart (fortification), a defensive wall or bank around a castle, fort or settlement Rampart may also refer to: * LAPD Rampart Division, a division of the Los Angeles Police Department ** Rampart scandal, a blanket ter .... The rim of Mädler is irregular and somewhat oblong in shape. There is a low central peak that joins a ridge crossing the floor. To the east of the crater are ray markings that include a ring-shape to the northeast. 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 Mädler. References * * * * * * * * * * * * {{DEFAULTSORT:Madler Impact craters on the Moon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sergey Glazenap
Sergey Pavlovich Glazenap (; 13(25) September 1848 - 12 April 1937) was a Russian Empire, Russian and Soviet Union, Soviet astronomer, honorary member of the Soviet Academy of Sciences (1929), and Hero of Socialist Labor (1932). In some publications, particularly in the 19th century, his last name was given as S. de Glasenapp (in French) or von Glasenapp (in German). He published ''Orbites des étoiles doubles du catalogue de Poulkova'', a study of double stars, for which he was awarded the Valz Prize in 1890. Glazenap (crater), Glazenap crater on the Moon and the minor planet 857 Glasenappia have been named after him. References Russian astronomers 1848 births 1937 deaths Heroes of Socialist Labour {{Europe-astronomer-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gregorian Calendar
The Gregorian calendar is the calendar used in most parts of the world. It went into effect in October 1582 following the papal bull issued by Pope Gregory XIII, which introduced it as a modification of, and replacement for, the Julian calendar. The principal change was to space leap years slightly differently to make the average calendar year 365.2425 days long rather than the Julian calendar's 365.25 days, thus more closely approximating the 365.2422-day tropical year, "tropical" or "solar" year that is determined by the Earth's revolution around the Sun. The rule for leap years is that every year divisible by four is a leap year, except for years that are divisible by 100, except in turn for years also divisible by 400. For example 1800 and 1900 were not leap years, but 2000 was. There were two reasons to establish the Gregorian calendar. First, the Julian calendar was based on the estimate that the average solar year is exactly 365.25 days long, an overestimate of a li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andreas Daum
Andreas W. Daum is a German-American historian who specializes in modern German and transatlantic history, as well as the history of knowledge and global exploration. Daum received his Ph.D. summa cum laude in 1995 from the Ludwig Maximilian University of Munich, where he taught for six years as an assistant professor. In 1996, he joined the German Historical Institute Washington DC as a research fellow. From 2001 to 2002, Daum was a John F. Kennedy Memorial Fellow at the Center for European Studies at Harvard University. Since 2003, he has been a professor of European history at the State University of New York (SUNY) at Buffalo. He also served as an associate dean for undergraduate education in the provost's office. In 2010–11, he was a visiting scholar at the BMW Center for German and European Studies at Georgetown University. He is best known as a biographer of Alexander von Humboldt and for his studies on popular science, emigrants from Nazi Germany, and the United State ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star Cluster
A star cluster is a group of stars held together by self-gravitation. Two main types of star clusters can be distinguished: globular clusters, tight groups of ten thousand to millions of old stars which are gravitationally bound; and open clusters, less tight groups of stars, generally containing fewer than a few hundred members. As they move through the galaxy, over time, open clusters become disrupted by the gravitational influence of giant molecular clouds, so that the clusters we observe are often young. Even though they are no longer gravitationally bound, they will continue to move in broadly the same direction through space and are then known as stellar associations, sometimes referred to as ''moving groups''. Globular clusters, with more members and more mass, remain intact for far longer and the globular clusters we observe are usually billions of years old. Star clusters visible to the naked eye include the Pleiades and Hyades (star cluster), Hyades open clusters, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleiades
The Pleiades (), also known as Seven Sisters and Messier 45 (M45), is an Asterism (astronomy), asterism of an open cluster, open star cluster containing young Stellar classification#Class B, B-type stars in the northwest of the constellation Taurus (constellation), Taurus. At a distance of about 444 light-years, it is among the nearest star clusters to Earth and the nearest Messier object to Earth, being the most obvious star cluster to the naked eye in the night sky. It is also observed to house the reflection nebula NGC 1432, an HII region. Around 2330 BC it marked the vernal point. Due to the brightness of its stars, the Pleiades is viewable from most areas on Earth, even in locations with significant light pollution. The cluster is dominated by OB star, hot blue luminous stars that have formed within the last 100 million years. Reflection nebulae around the brightest stars were once thought to be leftover material from their formation, but are now considered likely to be an u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proper Motion
Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable reference such as the International Celestial Reference Frame (ICRF). Patterns in proper motion reveal larger structures like stellar streams, the general rotation of the Milky Way disk, and the random motions of stars in the Galactic halo. The components for proper motion in the equatorial coordinate system (of a given epoch, often J2000.0) are given in the direction of right ascension (''μ''α) and of declination (''μ''δ). Their combined value is computed as the ''total proper motion'' (''μ''). It has dimensions of angle per time, typically arcseconds per year or milliarcseconds per year. Knowledge of the proper motion, distance, and radial velocity allows calculations of an object's motion from the Solar System's frame of reference an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Double Star
In observational astronomy, a double star or visual double is a pair of stars that appear close to each other as viewed from Earth, especially with the aid of optical telescopes. This occurs because the pair either forms a binary star (i.e. a binary system of stars in mutual orbit, gravitationally bound to each other) or is an ''optical double'', a chance line-of-sight alignment of two stars at different distances from the observer. Binary stars are important to stellar astronomers as knowledge of their motions allows direct calculation of stellar mass and other stellar parameters. The only (possible) case of "binary star" whose two components are separately visible to the naked eye is the case of Mizar and Alcor (though actually a multiple-star system), but it is not known for certain whether Mizar and Alcor are gravitationally bound. Since the beginning of the 1780s, both professional and amateur double star observers have telescopically measured the distances and angles be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meteorology
Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture, construction, weather warnings and disaster management. Along with climatology, atmospheric physics and atmospheric chemistry, meteorology forms the broader field of the atmospheric sciences. The interactions between Earth's atmosphere and its oceans (notably El Niño and La Niña) are studied in the interdisciplinary field of hydrometeorology. Other interdisciplinary areas include biometeorology, space weather and planetary meteorology. Marine weather forecasting relates meteorology to maritime and coastal safety, based on atmospheric interactions with large bodies of water. Meteorologists study meteorological phenomena driven by solar radiation, Earth's rotation, ocean currents and other factors. These include everyday ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulkovo Observatory
The Pulkovo Astronomical Observatory (), officially named the Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, is the principal astronomical observatory of the Russian Academy of Sciences. It is located 19 km south of Saint Petersburg on Pulkovo Heights above sea level. It is part of the UNESCO World Heritage Site Historic Centre of Saint Petersburg and Related Groups of Monuments. It was formerly known as the Imperial Observatory at Pulkowo. Early years The observatory was opened in 1839. Originally, it was a brainchild of the German/Russian astronomer Friedrich Georg Wilhelm von Struve, who would become its first director (in 1861, his son Otto Wilhelm von Struve succeeded him). The architect was Alexander Bryullov. The observatory was equipped with state-of-the-art devices, one of them being the a aperture refractor, one of the largest refractors in the world at that time (see Great Refractor). In 1885, the observatory was equipped wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
