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NGC 2423-3
NGC 2423-3 is a red giant star approximately 2498 light-years away in the constellation of Puppis. The star is part of the NGC 2423 open cluster (hence the name ''NGC 2423-3''). The star has an apparent magnitude of nine and an absolute magnitude of zero, with a mass of 2.4 times the Sun. As of 2007, it has been confirmed that an extrasolar planet orbits the star. Planetary system NGC 2423-3 b is an exoplanet 10.6 times more massive than Jupiter, even more massive than Pi Mensae b, which has mass about 10.3 times Jupiter. Only the minimum mass is known since the orbital inclination is not known, so it is likely to be a brown dwarf instead, like NGC 4349-127 b. The planet orbits at 10.2 μpc, taking 1.956 years to orbit eccentrically around the star. Its eccentricity is about the same as Mercury, but less than Pluto. The planet has semi-amplitude of 71.5 m/s since if 10.6 planet orbits at 2.1 AU from 2.4 MS star. This planet was discovered by Chad Lovis and Michel Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Puppis
Puppis is a constellation in the southern sky. Puppis, the Latin translation of " poop deck", was originally part of an over-large constellation Argo Navis (the ship of Jason and the Argonauts), which centuries after its initial description, was divided into three parts, the other two being Carina (the keel and hull), and Vela (the sails of the ship). Puppis is the largest of the three constellations in square degrees. It is one of the 88 modern constellations recognized by the International Astronomical Union. Features Argo Navis was sub-divided into three sections in 1752 by the French astronomer Nicolas Louis de Lacaille, including Argûs in puppi. Despite the division, Lacaille kept a single set of Bayer designations for the whole constellation, Argo. Therefore, Carina has the α, β, and ε, Vela has γ and δ, Puppis has ζ, and so on. In the 19th century, these three sections of Argo became established as separate constellations and were formally included in the list o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pi Mensae B
Pi Mensae b (π Men b, π Mensae b), also known as HD 39091 b, is an extrasolar planet approximately 59 light-years away in the constellation of Mensa. The planet was announced orbiting the yellow main-sequence star Pi Mensae in October 2001. Detection and discovery On October 15, 2001, a team of astronomers including Jones, Butler, Tinney, Marcy, Penny, McCarthy, Carter, and Pourbaix announced the discovery of one of the most massive extrasolar planets that have yet been observed. It was discovered by the Anglo-Australian Planet Search team, using a Doppler spectrometer mounted on the Anglo-Australian Telescope. Physical characteristics Pi Mensae b has a very eccentric orbit and takes 5.72 years to revolve around the star. The semi-major axis of the planet's orbit around the star is 3.31 AU. This planet passes through the star's habitable zone at periastron (1.19 AU) while at apastron, it passes to around Jupiter-Sun distance (5.44 AU). The gravitational influence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 69830
HD 69830 (285 G. Puppis) is a yellow dwarf star located approximately 41 light-years away in the constellation of Puppis. In 2005, the Spitzer Space Telescope discovered a narrow ring of warm debris orbiting the star. The debris ring contains substantially more dust than the Solar System's asteroid belt. In 2006, three extrasolar planets with minimum masses comparable to Neptune were confirmed in orbit around the star, located interior to the debris ring. Distance and visibility HD 69830 is a main sequence star of spectral type G8V. It has about 86% of the Sun's mass, 90% of its radius, 62% of its luminosity, and 89% of its iron abundance. The star's age has been estimated at about 10.6 ± 4 billion years. HD 69830 is located about 40.7 light-years from the Sun, lying in the northeastern part of the constellation of Puppis (the Poop Deck). It can be seen east of Sirius, southwest of Procyon, northeast of Delta Canis Majoris, and north of Zeta Puppis. Planetary syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptune
Neptune is the eighth planet from the Sun and the farthest known planet in the Solar System. It is the fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 times the mass of Earth, and slightly more massive than its near-twin Uranus. Neptune is denser and physically smaller than Uranus because its greater mass causes more gravitational compression of its atmosphere. It is referred to as one of the solar system's two ice giant planets (the other one being Uranus). Being composed primarily of gases and liquids, it has no well-defined "solid surface". The planet orbits the Sun once every 164.8 years at an average distance of . It is named after the Roman god of the sea and has the astronomical symbol , representing Neptune's trident. Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Michel Mayor
Michel Gustave Édouard Mayor (; born 12 January 1942) is a Swiss astrophysicist and professor emeritus at the University of Geneva's Department of Astronomy. He formally retired in 2007, but remains active as a researcher at the Observatory of Geneva. He is co-laureate of the 2019 Nobel Prize in Physics along with Jim Peebles and Didier Queloz, and the winner of the 2010 Viktor Ambartsumian International Prize and the 2015 Kyoto Prize. Together with Didier Queloz in 1995, he discovered 51 Pegasi b, the first extrasolar planet orbiting a sun-like star, 51 Pegasi. For this achievement, they were awarded the 2019 Nobel Prize in Physics "for the discovery of an exoplanet orbiting a solar-type star" resulting in “contributions to our understanding of the evolution of the universe and Earth’s place in the cosmos.” Related to the discovery, Mayor noted that humans will never migrate to such exoplanets since they are "much, much too far away ... nd would takehundreds of mil ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chad Lovis
Chad (; ar, تشاد , ; french: Tchad, ), officially the Republic of Chad, '; ) is a landlocked country at the crossroads of North and Central Africa. It is bordered by Libya to the north, Sudan to the east, the Central African Republic to the south, Cameroon to the southwest, Nigeria to the southwest (at Lake Chad), and Niger to the west. Chad has a population of 16 million, of which 1.6 million live in the capital and largest city of N'Djamena. Chad has several regions: a desert zone in the north, an arid Sahelian belt in the centre and a more fertile Sudanian Savanna zone in the south. Lake Chad, after which the country is named, is the second-largest wetland in Africa. Chad's official languages are Arabic and French. It is home to over 200 different ethnic and linguistic groups. Islam (55.1%) and Christianity (41.1%) are the main religions practiced in Chad. Beginning in the 7th millennium BC, human populations moved into the Chadian basin in great numbers. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meter Per Second
The metre per second is the unit of both speed (a scalar quantity) and velocity (a vector quantity, which has direction and magnitude) in the International System of Units (SI), equal to the speed of a body covering a distance of one metre in a time of one second. The SI unit symbols are m/s, m·s−1, m s−1, or . Sometimes it is abbreviated as "mps". Conversions is equivalent to: : = 3.6 km/h (exactly) : ≈ 3.2808 feet per second (approximately) : ≈ 2.2369 miles per hour (approximately) : ≈ 1.9438 knots (approximately) 1 foot per second = (exactly) 1 mile per hour = (exactly) 1 km/h = (exactly) Relation to other measures The benz, named in honour of Karl Benz, has been proposed as a name for one metre per second. Although it has seen some support as a practical unit, primarily from German sources, it was rejected as the SI unit of velocity and has not seen widespread use or acceptance. Unicode character The "metre per second" symbol is encoded by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amplitude
The amplitude of a periodic variable is a measure of its change in a single period (such as time or spatial period). The amplitude of a non-periodic signal is its magnitude compared with a reference value. There are various definitions of amplitude (see below), which are all functions of the magnitude of the differences between the variable's extreme values. In older texts, the phase of a periodic function is sometimes called the amplitude. Definitions Peak amplitude & semi-amplitude For symmetric periodic waves, like sine wave A sine wave, sinusoidal wave, or just sinusoid is a curve, mathematical curve defined in terms of the ''sine'' trigonometric function, of which it is the graph of a function, graph. It is a type of continuous wave and also a Smoothness, smooth p ...s, square waves or triangle waves ''peak amplitude'' and ''semi amplitude'' are the same. Peak amplitude In audio system measurements, telecommunications and others where the wikt:measurand, measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known trans-Neptunian object by volume, by a small margin, but is slightly less massive than Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Compared to Earth's moon, Pluto has only one sixth its mass and one third its volume. Pluto has a moderately eccentric and inclined orbit, ranging from from the Sun. Light from the Sun takes 5.5 hours to reach Pluto at its average distance (). Pluto's eccentric orbit periodically brings it closer to the Sun than Neptune, but a stable orbital resonance prevents them from colliding. Pluto has five known moons: Charon, the largest, whose diameter is just over half that of Pluto; Styx; Nix; Kerberos; and Hydra. Pluto and Char ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (planet)
Mercury is the smallest planet in the Solar System and the closest to the Sun. Its orbit around the Sun takes 87.97 Earth days, the shortest of all the Sun's planets. It is named after the Roman god ' ( Mercury), god of commerce, messenger of the gods, and mediator between gods and mortals, corresponding to the Greek god Hermes (). Like Venus, Mercury orbits the Sun within Earth's orbit as an inferior planet, and its apparent distance from the Sun as viewed from Earth never exceeds 28°. This proximity to the Sun means the planet can only be seen near the western horizon after sunset or the eastern horizon before sunrise, usually in twilight. At this time, it may appear as a bright star-like object, but is more difficult to observe than Venus. From Earth, the planet telescopically displays the complete range of phases, similar to Venus and the Moon, which recurs over its synodic period of approximately 116 days. The synodic proximity of Mercury to Earth makes Mercury ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microparsec
The parsec (symbol: pc) is a unit of length used to measure the large distances to astronomical objects outside the Solar System, approximately equal to or (au), i.e. . The parsec unit is obtained by the use of parallax and trigonometry, and is defined as the distance at which 1 au subtends an angle of one arcsecond ( of a degree). This corresponds to astronomical units, i.e. 1\, \mathrm = 1/\tan \left( \ \mathrm \right)\, \mathrm. The nearest star, Proxima Centauri, is about from the Sun. Most stars visible to the naked eye are within a few hundred parsecs of the Sun, with the most distant at a few thousand. The word ''parsec'' is a portmanteau of "parallax of one second" and was coined by the British astronomer Herbert Hall Turner in 1913 to make calculations of astronomical distances from only raw observational data easy for astronomers. Partly for this reason, it is the unit preferred in astronomy and astrophysics, though the light-year remains prominent in popular sci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NGC 4349-127 B
NGC 4349-127 is a probable red giant star approximately 6,100 light-years away in the constellation of Crux. It is a member of the open cluster NGC 4349 (hence the name ''NGC 4349-127''). Its mass is estimated at 3.9 times Solar, and its age is about 200 million years. In 2007, this star was found to have a substellar companion. NGC 4349-127 b is a brown dwarf (based on its mass) with nearly 20 times the mass of Jupiter. Within an eccentricity of about 0.19, its orbit is moderately elliptical, about the same as Mercury in the Solar System. It orbits its host star at a distance of 2.38 AU in a period of 677.8 days. This object was discovered by Christophe Lovis and Michel Mayor of the Geneva Observatory using the radial velocity technique. However, a 2018 study with the same C. Lovis as an author found that the radial velocity signal corresponding to the proposed substellar companion was most likely caused by stellar activity, and thus the companion does not exist. Anoth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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