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41 Daphne
Daphne (minor planet designation: 41 Daphne) is a large asteroid from the asteroid belt. It is a dark-surfaced body 174 km in diameter is probably composed of primitive carbonaceous chondrites. The spectra of the asteroid displays evidence of aqueous alteration. It was discovered by H. Goldschmidt on May 22, 1856, and named after Daphne, the nymph in Greek mythology who was turned into a laurel tree. Incorrect orbital calculations initially resulted in 56 Melete being mistaken for a second sighting of Daphne. Daphne was not sighted again until August 31, 1862. The orbit of 41 Daphne places it in a 9:22 mean motion resonance with the planet Mars. The computed Lyapunov time for this asteroid is 14,000 years, indicating that it occupies a chaotic orbit that will change randomly over time because of gravitational perturbations of the planets. In 1999, Daphne occulted three stars, and on July 2, 1999, produced eleven chords indicating an ellipsoid of 213×160 km. Daphne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Mayer Salomon Goldschmidt
Hermann Mayer Salomon Goldschmidt (June 17, 1802 – August 30 or September 10 1866) was a German-French astronomer and painter who spent much of his life in France. He started out as a painter, but after attending a lecture by the famous French astronomer Urbain Le Verrier turned to astronomy. His discovery of the asteroid Lutetia in 1852 was followed by further findings and by 1861 Goldschmidt had discovered 14 asteroids. He received the Gold Medal of the Royal Astronomical Society in 1861 for having discovered more asteroids than any other person up to that time. He died from complications of diabetes. Life and work Goldschmidt was born in Frankfurt as the son of a Jewish merchant. During a journey to the Netherlands, Goldschmidt visited Dutch picture galleries. The impression of this visit convinced him to become a painter. He studied art in Munich for several years under supervision of such famous painters as Peter von Cornelius and Julius Schnorr von Carolsfeld. To c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Motion Resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationship is found between a pair of objects (binary resonance). The physical principle behind orbital resonance is similar in concept to pushing a child on a swing (seat), swing, whereby the orbit and the swing both have a natural frequency, and the body doing the "pushing" will act in periodic repetition to have a cumulative effect on the motion. Orbital resonances greatly enhance the mutual gravitational influence of the bodies (i.e., their ability to alter or constrain each other's orbits). In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be self-correcting and thus stable. Examples are the 1:2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Bureau For Astronomical Telegrams
The Central Bureau for Astronomical Telegrams (CBAT) is the official international clearing house for information relating to transient astronomical events. The CBAT collects and distributes information on comets, natural satellites, novae, supernovae and other transient astronomical events. CBAT also establishes priority of discovery (who gets credit for it) and assigns initial designations and names to new objects. On behalf of the International Astronomical Union (IAU), the CBAT distributes ''IAU Circulars''. From the 1920s to 1992, CBAT sent telegrams in urgent cases, although most circulars were sent via regular mail; when telegrams were dropped, the name "telegram" was kept for historical reasons, and they continued as the ''Central Bureau Electronic Telegrams''. Since the mid-1980s the ''IAU Circulars'' and the related '' Minor Planet Circulars'' have been available electronically. The CBAT is a non-profit organization, but charges for its ''IAU Circulars'' and electronic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA Jet Propulsion Laboratory
The Jet Propulsion Laboratory (JPL) is a federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, United States. Founded in the 1930s by Caltech researchers, JPL is owned by NASA and managed by the nearby California Institute of Technology (Caltech). The laboratory's primary function is the construction and operation of planetary robotic spacecraft, though it also conducts Earth-orbit and astronomy missions. It is also responsible for operating the NASA Deep Space Network. Among the laboratory's major active projects are the Mars 2020 mission, which includes the ''Perseverance'' rover and the '' Ingenuity'' Mars helicopter; the Mars Science Laboratory mission, including the ''Curiosity'' rover; the InSight lander (''Interior Exploration using Seismic Investigations, Geodesy and Heat Transport''); the ''Mars Reconnaissance Orbiter''; the ''Juno'' spacecraft orbiting Jupiter; the ''SMAP'' satellite for earth surface s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pineios (Thessaly)
The Pineios ( el, Πηνειός, Pineiós, , , referred to in Latin sources as Peneus) is a river in Thessaly, Greece. The river is named after the god Peneus. During the later Middle Ages, it was also known as the Salamvrias or Salavrias (Σαλα ριάς). It flows from the Pindus mountains through the Thessalian plain and empties into the Aegean Sea, northeast of the Vale of Tempe, near Stomio. It creates a large delta, well known for its beauty and for many animal species, protected by international environmental treaties. Its total length is 205 km. Its drainage basin is . Its source is near the village Malakasi, on the eastern slope of the Pindus main range, east of Metsovo. The Meteora region and the city of Larissa lie along the Pineios. Trikala lies on its tributary, the Lithaios. In the 1960s, a freeway connecting Athens and Thessaloniki was constructed in much of the Vale of Tempe. Three ships of the Hellenic Navy have been named after the river. Tribu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peneus
In Greek mythology, Peneus (; Ancient Greek: Πηνειός) was a Thessalian river god, one of the three thousand Rivers (Potamoi), a child of Oceanus and Tethys. Family The nymph Creusa bore him one son, Hypseus, who was King of the Lapiths, and three daughters, Menippe (mother of Phrastor by Pelasgus), Daphne and Stilbe.Diodorus Siculus, 4.69.1 Some sources state that he was the father of Cyrene, alternately known as his granddaughter through Hypseus. Daphne, in an Arcadian version of the myth, was instead the daughter of the river god Ladon. Peneus also had a son Atrax with Bura, and Andreus with an unknown consort. Tricce (or Tricca), eponym of the city Tricca, was mentioned as his daughter. In later accounts, Peneus was credited to be the father of Chrysogenia who consorted with Zeus and became the mother of Thissaeus.Pseudo-Clement, '' Recognitions'' 10.21-23 Meanwhile, his daughter Astabe coupled with Hermes and became the parents of Astacus, father of Iocles, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radar Astronomy
Radar astronomy is a technique of observing nearby astronomical objects by reflecting radio waves or microwaves off target objects and analyzing their reflections. Radar astronomy differs from ''radio astronomy'' in that the latter is a passive observation (i.e., receiving only) and the former an active one (transmitting and receiving). Radar systems have been conducted for six decades applied to a wide range of Solar System studies. The radar transmission may either be pulsed or continuous. The strength of the radar return signal is proportional to the inverse fourth-power of the distance. Upgraded facilities, increased transceiver power, and improved apparatus have increased observational opportunities. Radar techniques provide information unavailable by other means, such as testing general relativity by observing Mercury and providing a refined value for the astronomical unit. Radar images provide information about the shapes and surface properties of solid bodies, which ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arecibo Observatory
The Arecibo Observatory, also known as the National Astronomy and Ionosphere Center (NAIC) and formerly known as the Arecibo Ionosphere Observatory, is an observatory in Barrio Esperanza, Arecibo, Puerto Rico owned by the US National Science Foundation (NSF). The observatory's main instrument was the Arecibo Telescope, a spherical reflector dish built into a natural sinkhole, with a cable-mount steerable receiver and several radar transmitters for emitting signals mounted above the dish. Completed in 1963, it was the world's largest single-aperture telescope for 53 years, surpassed in July 2016 by the Five-hundred-meter Aperture Spherical Telescope (FAST) in China. Following two breaks in cables supporting the receiver platform in mid-2020, the NSF decommissioned the telescope. A partial collapse of the telescope occurred on December 1, 2020, before controlled demolition could be conducted. In 2022, the NSF announced the telescope will not be rebuilt, with an educational fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightcurve
In astronomy, a light curve is a graph of light intensity of a celestial object or region as a function of time, typically with the magnitude of light received on the y axis and with time on the x axis. The light is usually in a particular frequency interval or band. Light curves can be periodic, as in the case of eclipsing binaries, Cepheid variables, other periodic variables, and transiting extrasolar planets, or aperiodic, like the light curve of a nova, a cataclysmic variable star, a supernova or a microlensing event or binary as observed during occultation events. The study of the light curve, together with other observations, can yield considerable information about the physical process that produces it or constrain the physical theories about it. Variable stars Graphs of the apparent magnitude of a variable star over time are commonly used to visualise and analyse their behaviour. Although the categorisation of variable star types is increasingly done from their spe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chord (astronomy)
In the field of astronomy the term chord typically refers to a line crossing an object which is formed during an occultation event. By taking accurate measurements of the start and end times of the event, in conjunction with the known location of the observer and the object's orbit, the length of the chord can be determined giving an indication of the size of the occulting object. By combining observations made from several different locations, multiple chords crossing the occulting object can be determined giving a more accurate shape and size model. This technique of using multiple observers during the same event has been used to derive more sophisticated shape models for asteroids, whose shape can be highly irregular. A notable example of this occurred in 2002 when the asteroid 345 Tercidina underwent a stellar occultation of a very bright star as seen from Europe. During this event a team of at least 105 observers recorded 75 chords across the asteroid's surface allowing for a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star
A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked eye at night sky, night, but their immense distances from Earth make them appear as fixed stars, fixed points of light. The most prominent stars have been categorised into constellations and asterism (astronomy), asterisms, and many of the brightest stars have proper names. Astronomers have assembled star catalogues that identify the known stars and provide standardized stellar designations. The observable universe contains an estimated to stars. Only about 4,000 of these stars are visible to the naked eye, all within the Milky Way galaxy. A star's life star formation, begins with the gravitational collapse of a gaseous nebula of material composed primarily of hydrogen, along with helium and trace amounts of heavier elements. Its stellar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occultation
An occultation is an event that occurs when one object is hidden from the observer by another object that passes between them. The term is often used in astronomy, but can also refer to any situation in which an object in the foreground blocks from view (occults) an object in the background. In this general sense, occultation applies to the visual scene observed from low-flying aircraft (or computer-generated imagery) when foreground objects obscure distant objects dynamically, as the scene changes over time. If the closer body does not entirely conceal the farther one, the event is called a ''transit''. Both transit and occultation may be referred to generally as ''occlusion''; and if a shadow is cast onto the observer, it is called an eclipse. The symbol for an occultation, and especially a solar eclipse, is file:Occultation symbol.svg (U+1F775 🝵). Occultations by the Moon The term occultation is most frequently used to describe lunar occultations, those relativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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