|
HD 129445 B
HD 129445 b is an eccentric Jupiter gas giant exoplanet orbiting the star HD 129445 which was discovered by the Magellan Planet Search Program in 2010. Its minimum mass is 1.6 times Jupiter's, and it takes 5 years to complete one orbit around HD 129445, a G-type star A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temp ... approximately 219 light years away. In 2023, the inclination and true mass of HD 129445 b were determined via astrometry. References {{Circinus Exoplanets discovered in 2010 Exoplanets detected by radial velocity Giant planets Circinus Exoplanets detected by astrometry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Las Campanas Observatory
Las Campanas Observatory (LCO) is an astronomical observatory owned and operated by the Carnegie Institution for Science (CIS). It is in the southern Atacama Desert of Chile in the Atacama Region approximately northeast of the city of La Serena. The LCO telescopes and other facilities are near the north end of a long mountain ridge. Cerro Las Campanas, near the southern end and over high, is the future home of the Giant Magellan Telescope. LCO was established in 1969 and is the primary observing facility of CIS. It supplanted Mount Wilson Observatory in that role due to increasing light pollution in the Los Angeles area. The headquarters of Carnegie Observatories is located in Pasadena, California, while the main office in Chile is in La Serena next to the University of La Serena and a short distance from the Association of Universities for Research in Astronomy facility. It is served by Pelicano Airport, to the southwest. Telescopes * The Magellan Telescopes are two i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Spectroscopy
Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. 1,018 extrasolar planets (about 19.5% of the total) have been discovered using Doppler spectroscopy, as of November 2022. History Otto Struve proposed in 1952 the use of powerful spectrographs to detect distant planets. He described how a very large planet, as large as Jupiter, for example, would cause its parent star to wobble slightly as the two objects orbit around their center of mass. He predicted that the small Doppler shifts to the light emitted by the star, caused by its continuously varying radial velocity, would be detectable by the most sensitive spectrographs as tiny redshifts and blueshifts in the star's emission. However, the technology of the time produced radial-velocity meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 129445
HD 129445 is a G type star found in the Circinus constellation located approximately 220 light-years away from the Sun based on parallax. It is invisible to the naked eye with an apparent visual magnitude of 8.80. The star has been under the Magellan Planet Search Program observation due to its absolute visual magnitude and high metallicity. The Magellan program conducted 17 doppler velocity tests, which spans a full orbital period. The results led the program to detect a planet dubbed HD 129445 b whose readings was accurate to the Keplerian orbital model. See also * HD 152079 * HD 164604 * HD 175167 * HD 86226 * List of extrasolar planets These are lists of exoplanets. Most of these were discovered by the Kepler space telescope. There are an additional 2,054 potential exoplanets from Kepler's first mission yet to be confirmed, as well as 978 from its " Second Light" mission and ... References {{DEFAULTSORT:HD 129445 G-type main-sequence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentric Jupiter
An eccentric Jupiter is a Jovian planet that orbits its star in an eccentric orbit. Note: this study treats eccentric Jupiters as giant planets having an orbital eccentricity of 0.1 or greater. Eccentric Jupiters may probably disqualify a planetary system from having Earth-like planets (though not always from having habitable exomoons) in it because a massive gas giant with an eccentric orbit may remove all Earth mass exoplanets from the habitable zone, if not from the system entirely. The planets of the solar system, except for Mercury, have orbits with an eccentricity of less than 0.1 and are moving in a state close to a perfect circle. However, two-thirds of the exoplanets discovered in 2006 have elliptical orbits with an eccentricity of 0.2 or more. The typical exoplanet with an orbital period greater than 5 days has a median eccentricity of 0.23. This, together with Hot Jupiter, provided an opportunity to fundamentally review the theory of solar system formation so far. Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gas Giant
A gas giant is a giant planet composed mainly of hydrogen and helium. Gas giants are also called failed stars because they contain the same basic elements as a star. Jupiter and Saturn are the gas giants of the Solar System. The term "gas giant" was originally synonymous with "giant planet". However, in the 1990s, it became known that Uranus and Neptune are really a distinct class of giant planets, being composed mainly of heavier volatile substances (which are referred to as "ices"). For this reason, Uranus and Neptune are now often classified in the separate category of ice giants. Jupiter and Saturn consist mostly of hydrogen and helium, with heavier elements making up between 3 and 13 percent of their mass.The Interior of Jupiter, Guillot et al., in ''Jupiter: The Planet, Satellites and Magnetosphere'', Bagenal et al., editors, Cambridge University Press, 2004 They are thought to consist of an outer layer of compressed molecular hydrogen surrounding a layer of liquid metallic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanet
An exoplanet or extrasolar planet is a planet outside the Solar System. The first possible evidence of an exoplanet was noted in 1917 but was not recognized as such. The first confirmation of detection occurred in 1992. A different planet, initially detected in 1988, was confirmed in 2003. There are many methods of detecting exoplanets. Transit photometry and Doppler spectroscopy have found the most, but these methods suffer from a clear observational bias favoring the detection of planets near the star; thus, 85% of the exoplanets detected are inside the tidal locking zone. In several cases, multiple planets have been observed around a star. About 1 in 5 Sun-like starsFor the purpose of this 1 in 5 statistic, "Sun-like" means G-type star. Data for Sun-like stars was not available so this statistic is an extrapolation from data about K-type stars. have an "Earth-sized"For the purpose of this 1 in 5 statistic, Earth-sized means 1–2 Earth radii. planet in the habitable zone. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magellan Planet Search Program
The Magellan Planet Search Program is a ground-based search for extrasolar planets that makes use of the radial velocity method. It began gathering data in December 2002 using thMIKE echelle spectrograph mounted on the 6.5m Magellan II "Clay" telescope located within the Las Campanas Observatory in Chile. In 2010, the program began using the newly commissionePlanet Finder Spectrograph(PFS), an instrument purpose-built for precise radial velocity measurement. Specifications The Magellan Planet Search uses a molecular Iodine absorption cell to imprint a set of extremely well known absorption lines onto each stellar spectrum that act as a fiducial wavelength reference. In the early years of the program, MIKE spectra were collected with a resolving power, R, of about 65,000 and achieved velocity precision of several meters per second. Using PFS, most spectra are collected with a resolving power of about 80,000 and velocity precision closer to one meter per second. Observations T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minimum Mass
In astronomy, minimum mass is the lower-bound calculated mass of observed objects such as planets, stars and binary systems, nebulae, and black holes. Minimum mass is a widely cited statistic for extrasolar planets detected by the radial velocity method or Doppler spectroscopy, and is determined using the binary mass function. This method reveals planets by measuring changes in the movement of stars in the line-of-sight, so the real orbital inclinations and true masses of the planets are generally unknown. This is a result of sin ''i'' degeneracy. If inclination ''i'' can be determined, the true mass can be obtained from the calculated minimum mass using the following relationship: M_\text = \frac Exoplanets Orientation of the transit to Earth Most stars will not have their planets lined up and orientated so that they eclipse over the center of the star and give the viewer on earth a perfect transit. It is for this reason that when we often are only able to extrapolate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-type Main-sequence Star
A G-type main-sequence star (Spectral type: G-V), also often, and imprecisely called a yellow dwarf, or G star, is a main-sequence star (luminosity class V) of spectral type G. Such a star has about 0.9 to 1.1 solar masses and an effective temperature between about 5,300 and 6,000 K. Like other main-sequence stars, a G-type main-sequence star is converting the element hydrogen to helium in its core by means of nuclear fusion, but can also fuse helium when hydrogen runs out. The Sun, the star in the center of the Solar System to which the Earth is gravitationally bound, is an example of a G-type main-sequence star (G2V type). Each second, the Sun fuses approximately 600 million tons of hydrogen into helium in a process known as the proton–proton chain (4 hydrogens form 1 helium), converting about 4 million tons of matter to energy. Besides the Sun, other well-known examples of G-type main-sequence stars include Alpha Centauri, Tau Ceti, Capella and 51 Pegasi. The term ''yel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astrometry
Astrometry is a branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. It provides the kinematics and physical origin of the Solar System and this galaxy, the Milky Way. History The history of astrometry is linked to the history of star catalogues, which gave astronomers reference points for objects in the sky so they could track their movements. This can be dated back to Hipparchus, who around 190 BC used the catalogue of his predecessors Timocharis and Aristillus to discover Earth's precession. In doing so, he also developed the brightness scale still in use today. Hipparchus compiled a catalogue with at least 850 stars and their positions. Hipparchus's successor, Ptolemy, included a catalogue of 1,022 stars in his work the '' Almagest'', giving their location, coordinates, and brightness. In the 10th century, Abd al-Rahman al-Sufi carried out observations on the stars and described their positions, ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Research In Astronomy And Astrophysics
''Research in Astronomy and Astrophysics'' is a monthly peer-reviewed scientific journal covering all branches of astronomy and astrophysics. It was established in 1981 as ''Acta Astrophysica Sinica'' and published in Chinese. It was renamed ''Chinese Journal of Astronomy and Astrophysics'' in 2001, switching to publication in English and restarting volume numbering. It obtained its current name in 2009. The journal is published by IOP Publishing, on behalf of the National Astronomical Observatory of China and the Chinese Astronomical Society. The editor-in-chief is Jingxiu Wang (National Astronomical Observatory of China). According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 1.469. References Ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Doppler Spectroscopy")
