|
HD 108874 B
HD 108874 b is a gas giant announced in 2003. The orbit lies in the star's habitable zone. It is expected that any moons orbiting this planet are enriched in carbon, and are thus quite different from the silicate-rich bodies in the Solar System. The planet is possibly in a 4 : 1 orbital resonance with HD 108874 c. Discovery The jovian planet HD 108874 b was discovered by the US-based team led by Paul Butler, Geoffrey Marcy, Steven Vogt, and Debra Fischer. A total of 20 radial velocity observations, obtained at the W. M. Keck Observatory in Hawaii between 1999 and 2002, were used to make the discovery. See also * HD 28185 b HD 28185 b is an extrasolar planet 128 light-years away from Earth in the constellation of Eridanus (constellation), Eridanus. The planet was discovered orbiting the Sun-like star HD 28185 in April 2001 as a part of the CORALIE survey for southern ... References External links * Coma Berenices Exoplanets discovered in 2003 Giant planets Giant ... [...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] |
Jovian Planet
The giant planets constitute a diverse type of planet much larger than Earth. They are usually primarily composed of low-boiling-point materials (volatiles), rather than rock or other solid matter, but massive solid planets can also exist. There are four known giant planets in the Solar System: Jupiter, Saturn, Uranus and Neptune. Many extrasolar giant planets have been identified orbiting other stars. They are also sometimes called jovian planets, after Jupiter ("Jove" being another name for the Roman god "Jupiter"). They are also sometimes known as gas giants. However, many astronomers now apply the latter term only to Jupiter and Saturn, classifying Uranus and Neptune, which have different compositions, as ice giants. Both names are potentially misleading: all of the giant planets consist primarily of fluids above their critical points, where distinct gas and liquid phases do not exist. The principal components are hydrogen and helium in the case of Jupiter and Saturn, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giant Planets
The giant planets constitute a diverse type of planet much larger than Earth. They are usually primarily composed of low-boiling-point materials (volatiles), rather than rock or other solid matter, but massive solid planets can also exist. There are four known giant planets in the Solar System: Jupiter, Saturn, Uranus and Neptune. Many extrasolar giant planets have been identified orbiting other stars. They are also sometimes called jovian planets, after Jupiter ("Jove" being another name for the Roman god "Jupiter"). They are also sometimes known as gas giants. However, many astronomers now apply the latter term only to Jupiter and Saturn, classifying Uranus and Neptune, which have different compositions, as ice giants. Both names are potentially misleading: all of the giant planets consist primarily of fluids above their critical points, where distinct gas and liquid phases do not exist. The principal components are hydrogen and helium in the case of Jupiter and Saturn, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Discovered In 2003
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.F ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coma Berenices
Coma Berenices is an ancient asterism in the northern sky, which has been defined as one of the 88 modern constellations. It is in the direction of the fourth galactic quadrant, between Leo and Boötes, and it is visible in both hemispheres. Its name means "Berenice's Hair" in Latin and refers to Queen Berenice II of Egypt, who sacrificed her long hair as a votive offering. It was introduced to Western astronomy during the third century BC by Conon of Samos and was further corroborated as a constellation by Gerardus Mercator and Tycho Brahe. It is the only modern constellation named for a historic person. The constellation's major stars are Alpha, Beta, and Gamma Comae Berenices. They form a half square, along the diagonal of which run Berenice's imaginary tresses, formed by the Coma Star Cluster. The constellation's brightest star is Beta Comae Berenices, a 4.2-magnitude main sequence star similar to the Sun. Coma Berenices contains the North Galactic Pole and one of the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 28185 B
HD 28185 b is an extrasolar planet 128 light-years away from Earth in the constellation of Eridanus (constellation), Eridanus. The planet was discovered orbiting the Sun-like star HD 28185 in April 2001 as a part of the CORALIE survey for southern extrasolar planets, and its existence was independently confirmed by the Magellan Planet Search Survey in 2008. HD 28185 b orbits its sun in a circular orbit that is at the inner edge of its star's habitable zone. Discovery HD 28185 b was discovered by detecting small periodic variations in the radial velocity of its parent star caused by the gravity, gravitational attraction of the planet. This was achieved by measuring the Doppler shift of the star's spectrum. In 2001 it was announced that HD 28185 exhibited a wobble along the line-of-sight with a period of 383 days, with an amplitude indicating a minimum mass 5.72 times that of Jupiter. Orbit and mass HD 28185 b takes 1.04 years to orbit its parent star. Unlike most known long-orb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii
Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only state geographically located within the tropics. Hawaii comprises nearly the entire Hawaiian archipelago, 137 volcanic islands spanning that are physiographically and ethnologically part of the Polynesian subregion of Oceania. The state's ocean coastline is consequently the fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Kauai, Oahu, Molokai, Lānai, Kahoolawe, Maui, and Hawaii—the last of these, after which the state is named, is often called the "Big Island" or "Hawaii Island" to avoid confusion with the state or archipelago. The uninhabited Northwestern Hawaiian Islands make up most of the Papahānaumokuākea Marine National Monument, the United States' largest protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Debra Fischer
Debra Ann Fischer is a professor of astronomy at Yale University researching detection and characterization of exoplanets. She was part of the team to discover the first known multiple-planet system. Education Fischer received her degree from the University of Iowa in 1975, a masters of science from San Francisco State University in 1992, and her PhD from the University of California at Santa Cruz in 1998. Research and career Fischer has co-authored over 100 papers on dwarf stars and sub-stellar mass objects in the galactic neighborhood, including many on extrasolar planets. Her work "The Twenty Five Year Lick Planet Search" is summarized in a paper by Fischer, Marcy & Spronck 2014. She is a principal investigator with the N2K Consortium searching for exoplanets. She co-leads the planet search team with Gregory P. Laughlin and Jessi Cisewski looking for extrasolar planets. She was the primary investigator for Chiron, the CTIO High Resolution Spectrometer. In 2011, she sta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steven Vogt
Steven Scott Vogt (born December 20, 1949) is an American astronomer of German descent whose main interest is the search for extrasolar planets. He is credited, along with R. Paul Butler, for discovering Gliese 581 g, the first potentially habitable planet outside of the Solar System. He is a professor of astronomy and astrophysics at the University of California, Santa Cruz, and is known worldwide for designing and building HIRES, a high-resolution optical spectrometer mounted permanently on the W. M. Keck Observatory 10-meter telescope on Mauna Kea, Hawaii. HIRES is an instrument critical to observations and discoveries about the planets, stars, galaxies, and the universe. Vogt also built the Hamilton spectrometer at Lick Observatory (with which most of the first extrasolar planets were discovered). In 1987, earlier in his career, Vogt invented the technique of "Doppler imaging" for mapping the surface features of stars. Vogt is currently a member of the California-Carnegi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geoffrey Marcy
Geoffrey William Marcy (born September 29, 1954) is an American astronomer. He was an early influence in the field of exoplanet detection, discovery, and characterization. Marcy was a professor of astronomy at the University of California, Berkeley, and an adjunct professor of physics and astronomy at San Francisco State University. Marcy and his research teams discovered many extrasolar planets, including 70 out of the first 100 known exoplanets and also the first planetary system around a Sun-like star, Upsilon Andromedae. Marcy was a co-investigator on the NASA ''Kepler'' mission. His collaborators have included R. Paul Butler, Debra Fischer and Steven S. Vogt, Jason Wright, Andrew Howard, Katie Peek, John Johnson, Erik Petigura, Lauren Weiss, Lea Hirsch and the Kepler Science Team. Early life and education Marcy graduated from Granada Hills High School in Granada Hills, California, in 1972. He graduated with a Bachelor of Arts '' summa cum laude'' with a double major in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 108874 C
HD 108874 c is a gas giant discovered in 2005 which orbits beyond the star's habitable zone, and receives insolation 15.9% that of Earth. It has minimum mass similar to Jupiter, although since the inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ... of the orbit is not known the true mass of this planet could be much greater. The planet is possibly in a 4 : 1 orbital resonance with HD 108874 b. References External links The Extrasolar Planets Encyclopedia: HD 108874 c Coma Berenices Giant planets Exoplanets discovered in 2005 Exoplanets detected by radial velocity {{extrasolar-planet-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HD 108874
HD 108874 is a yellow dwarf star (spectral type G5 V) in the constellation of Coma Berenices. It is 195 light years from Earth and has two extrasolar planets that are possibly in a 9:2 orbital resonance. Star HD 108874 is probably billions of years older than the Sun however the age is not well constrained. The star has a temperature of about 5600 K. Its metallicity is 1.18 times that of the Sun, meaning it has greater iron abundance relative to hydrogen and helium. It has about the same mass as the Sun, but the radius is probably greater. Planetary system In 2003, the jovian planet HD 108874 b was discovered by the US-based team led by R. Paul Butler, Paul Butler, Geoffrey Marcy, Steven Vogt, and Debra Fischer. A total of 20 radial velocity observations, obtained at the W. M. Keck Observatory between 1999 and 2002, were used to make the discovery. In 2005, further observations revealed this star has another jovian planet orbiting further out, designated as HD 108874 c. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
