|
HD 17156 B
HD 17156 b, named Mulchatna by the IAU, is an extrasolar planet approximately 255 light-years away in the constellation of Cassiopeia. The planet was discovered orbiting the yellow subgiant star HD 17156 in April 2007. The planet is classified as a relatively cool hot Jupiter planet slightly smaller than Jupiter but slightly larger than Saturn. This highly-eccentric three-week orbit takes it approximately 0.0523 AU of the star at periastron before swinging out to approximately 0.2665 AU at apastron. Its eccentricity is about the same as 16 Cygni Bb, a so-called "eccentric Jupiter". Until 2009, HD 17156 b was the transiting planet with the longest orbital period. Discovery The planet was discovered on April 14, 2007, by a team using the radial velocity method on the Keck and Subaru telescopes. The team made an initial negative, transit search, but they were only able to cover 25% of the search space. This left the possibility of a transit open. After the possibility o ... [...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] |
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] |
Exoplanets Discovered In 2007
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] |
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] |
The Astrophysical Journal
''The Astrophysical Journal'', often abbreviated ''ApJ'' (pronounced "ap jay") in references and speech, is a peer-reviewed Peer review is the evaluation of work by one or more people with similar competencies as the producers of the work (peers). It functions as a form of self-regulation by qualified members of a profession within the relevant field. Peer review ... scientific journal of astrophysics and astronomy, established in 1895 by American astronomers George Ellery Hale and James Edward Keeler. The journal discontinued its print edition and became an electronic-only journal in 2015. Since 1953 ''The Astrophysical Journal Supplement Series'' (''ApJS'') has been published in conjunction with ''The Astrophysical Journal'', with generally longer articles to supplement the material in the journal. It publishes six volumes per year, with two 280-page issues per volume. ''The Astrophysical Journal Letters'' (''ApJL''), established in 1967 by Subrahmanyan Chandrasekhar as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Secondary Eclipse
A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in which case they are called ''visual binaries''. Many visual binaries have long orbital periods of several centuries or millennia and therefore have orbits which are uncertain or poorly known. They may also be detected by indirect techniques, such as spectroscopy (''spectroscopic binaries'') or astrometry (''astrometric binaries''). If a binary star happens to orbit in a plane along our line of sight, its components will eclipse and transit each other; these pairs are called ''eclipsing binaries'', or, together with other binaries that change brightness as they orbit, ''photometric binaries''. If components in binary star systems are close enough they can gravitationally distort their mutual outer stellar atmospheres. In some cases, these ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rossiter–McLaughlin Effect
The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when an object moves across the face of a star. Description The Rossiter–McLaughlin effect is a spectroscopic phenomenon observed when either an eclipsing binary's secondary star or an extrasolar planet is seen to transit across the face of the primary or parent star. As the main star rotates on its axis, one quadrant of its photosphere will be seen to be coming towards the viewer, and the other visible quadrant to be moving away. These motions produce blueshifts and redshifts, respectively, in the star's spectrum, usually observed as a broadening of the spectral lines. When the secondary star or planet transits the primary, it blocks part of the latter's disc, preventing some of the shifted light from reaching the observer. That causes the observed mean redshift of the primary star as a whole to vary from its normal value. As the transiting object moves across to the other side of the star's disc, the red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nushagak River
The Nushagak River ( esu, Iilgayaq) is a river in southwest Alaska, United States. It begins in the Alaska Range and flows southwest to Nushagak Bay, an inlet of Bristol Bay, east of Dillingham, Alaska. The Mulchatna River is a major tributary. Other navigable tributaries include the Nuyakuk River and the King Salmon River. Jet-boats are commonly used to access these tributaries and the upper Nushagak. The Wood River, Iowithla River and the Kokwok River are smaller tributaries. The villages of Portage Creek, Ekwok, Koliganek and New Stuyahok are on the river. The town of Dillingham (Pop. 2,466) is on Nushagak Bay. The Nushagak River is downstream of the proposed Pebble Mine, whose tailings storage lake would sit at the headwaters of the Koktuli River, one of the Nushagak's tributaries. Villages on the Nushagak are among the major opponents of the proposal. Five species of Pacific salmon ( Chinook, coho, sockeye, chum, and pink) spawn in the river or its tributa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mulchatna River
The Mulchatna River ( Dena'ina: Vałts'atnaq') is a tributary of the Nushagak River in the U.S. state of Alaska. Beginning at Turquoise Lake, it flows generally southwest to meet the larger river northeast of Dillingham. The Mulchatna's mouth is slightly south (downstream) of the village of Koliganek on the Nushagak, which continues southwest to Nushagak Bay, an arm of Bristol Bay. The upper of the river, which flow through Lake Clark National Park and Preserve, became part of the National Wild and Scenic River System in 1980. Aside from scattered cabins, the Mulchatna River is undeveloped. However, there is a proposal to build a large copper/gold mine, the Pebble Mine, in the watershed of one of the Mulchatna tributaries, the Koktuli River. Recreation The Mulchatna River and one of its tributaries, the Chilikadrotna River, are popular Southwest Alaska destinations for floatfishing. Other Mulchatna tributaries, including the Stuyahok and Koktuli rivers, are also popular ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NameExoWorlds
NameExoWorlds (also known as IAU NameExoWorlds) is the name of various projects managed by the International Astronomical Union (I.A.U.) to encourage names to be submitted for astronomical objects, which would later be considered for official adoption by the organization. History The first such project (NameExoWorlds I), in 2015, regarded the naming of stars and exoplanets. 573,242 votes were submitted by members by the time the contest closed on October 31, 2015, and the names of 31 exoplanets and 14 stars were selected from these. Many of the names chosen were based on world history, mythology and literature. In June 2019, another such project (NameExoWorlds II), in celebration of the organization's hundredth anniversary, in a project officially called IAU100 NameExoWorlds, welcomed countries of the world to submit names for exoplanets and their host stars. A star with an exoplanet was assigned to each country, and members of the public submitted names for them. In August 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_effect.gif "Click for more on -> Rossiter–McLaughlin Effect")
.jpeg "Click for more on -> Nushagak River")
