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Cruinlagh
WASP-13b, also known as Cruinlagh, is an extrasolar planet that was discovered in 2008 in the orbit of the sunlike star WASP-13. The planet has a mass of nearly half that of Jupiter, but a radius five-quarters of the size of Jupiter. This low relative mass might be caused by a core that is of low mass or that is not present at all. The planet orbits at approximately 5% of the distance between the Sun and Earth every four days. The star was observed several times between 2006 and 2009, at first through the SuperWASP program and later through focused follow-up observations. Analysis of collected radial velocity measurements led to the discovery of Cruinlagh, which was reported in a journal on April 7, 2009. A follow-up study published in 2011 investigated the cause for inflated planets such as Cruinlagh, and re-examined (and re-constrained) its mass, radius, density, and age. Discovery Between November 27, 2006, and April 1, 2007, 3329 images of the star WASP-13, by the SuperWASP- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
WASP-13
WASP-13, also named Gloas, is a star in the Lynx constellation. The star is similar, in terms of metallicity and mass, to the Sun, although it is hotter and most likely older. The star was first observed in 1997, according to the SIMBAD database, and was targeted by SuperWASP after the star was observed by one of the SuperWASP telescopes beginning in 2006. Follow-up observations on the star led to the discovery of planet Cruinlagh in 2008; the discovery paper was published in 2009. Observational history According to SIMBAD, WASP-13 was first observed in 1997, when it was catalogued by astronomers measuring the proper motion of stars in regions of the sky where galaxies are detected. Between November 27, 2006, and April 1, 2007, the SuperWASP-North telescope in the Canary Islands observed WASP-13; analysis of the data suggested that a planet could be in the orbit of the star. Follow-up observations were conducted by a team of British, Spanish, French, Swiss and American a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SuperWASP
WASP or Wide Angle Search for Planets is an international consortium of several academic organisations performing an ultra-wide angle search for exoplanets using transit photometry. The array of robotic telescopes aims to survey the entire sky, simultaneously monitoring many thousands of stars at an apparent visual magnitude from about 7 to 13. WASP is the detection program composed of the Isaac Newton Group, IAC and six universities from the United Kingdom. The two continuously operating, robotic observatories cover the Northern and Southern Hemisphere, respectively. SuperWASP-North is at Roque de los Muchachos Observatory on the mountain of that name which dominates La Palma in the Canary Islands. WASP-South is at the South African Astronomical Observatory, Sutherland in the arid Roggeveld Mountains of South Africa. These use eight wide-angle cameras that simultaneously monitor the sky for planetary transit events and allow the monitoring of millions of stars simultaneousl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-7b
Kepler-7b is one of the first five exoplanets to be confirmed by NASA's Kepler spacecraft, and was confirmed in the first 33.5 days of Kepler's science operations. It orbits a star slightly hotter and significantly larger than the Sun that is expected to soon reach the end of the main sequence. Kepler-7b is a hot Jupiter that is about half the mass of Jupiter, but is nearly 1.5 times its size; at the time of its discovery, Kepler-7b was the second most diffuse planet known, surpassed only by WASP-17b. It orbits its host star every five days at a distance of approximately 0,06 AU (9.000.000 km or 5.592.340 mi). Kepler-7b was announced at a meeting of the American Astronomical Society on January 4, 2010. It is the first extrasolar planet to have a crude map of cloud coverage. Characteristics Mass, temperature, and orbit Kepler-7b is a hot Jupiter, a Jupiter-like exoplanet orbiting close to its star. Its equilibrium temperature, due to its proximity to its star, is hot and is measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter Radius
The Jupiter radius or Jovian radius ( or ) has a value of , or 11.2 Earth radii () (one Earth radius equals ). The Jupiter radius is a unit of length used in astronomy to describe the radii of gas giants and some extrasolar planets. It is also used in describing brown dwarfs. In 2015, the International Astronomical Union defined the ''nominal equatorial Jovian radius'' to remain constant regardless of subsequent improvements in measurement precision of . This constant is defined as exactly: :\mathcal^\mathrm N_\mathrm = Similarly, the ''nominal polar Jovian radius'' is defined to be exactly: :\mathcal^\mathrm N_\mathrm = These values correspond to the radius of Jupiter at 1 bar of pressure. The common usage is to refer to the equatorial radius, unless the polar radius is specifically needed. Comparison For comparison, one Solar radius is equivalent to: * 400 Lunar radius() * 109 Earth radius () * 9.735 Jupiter radius () References {{Jupiter Planetary science Units ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter Mass
Jupiter mass, also called Jovian mass, is the unit of mass equal to the total mass of the planet Jupiter. This value may refer to the mass of the planet alone, or the mass of the entire Jovian system to include the moons of Jupiter. Jupiter is by far the most massive planet in the Solar System. It is approximately 2.5 times as massive as all of the other planets in the Solar System combined. Jupiter mass is a common unit of mass in astronomy that is used to indicate the masses of other similarly-sized objects, including the outer planets, extrasolar planets, and brown dwarfs, as this unit provides a convenient scale for comparison. Current best estimates The current best known value for the mass of Jupiter can be expressed as : :M_\mathrm=(1.89813 \pm 0.00019)\times10^ \text, which is about as massive as the sun (is about ): :M_\mathrm=\frac M_ \approx (9.547919 \pm 0.000002) \times10^ M_. Jupiter is 318 times as massive as Earth: :M_\mathrm = 3.1782838 \times 10^2 M_\oplu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kelvin Scale
The kelvin, symbol K, is the primary unit of temperature in the International System of Units (SI), used alongside its prefixed forms and the degree Celsius. It is named after the Belfast-born and University of Glasgow-based engineer and physicist William Thomson, 1st Baron Kelvin (1824–1907). The Kelvin scale is an absolute thermodynamic temperature scale, meaning it uses absolute zero as its null (zero) point. Historically, the Kelvin scale was developed by shifting the starting point of the much-older Celsius scale down from the melting point of water to absolute zero, and its increments still closely approximate the historic definition of a degree Celsius, but since 2019 the scale has been defined by fixing the Boltzmann constant to be exactly . Hence, one kelvin is equal to a change in the thermodynamic temperature that results in a change of thermal energy by . The temperature in degree Celsius is now defined as the temperature in kelvins minus 273.15, meaning tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Effective Temperature
The effective temperature of a body such as a star or planet is the temperature of a black body that would emit the same total amount of electromagnetic radiation. Effective temperature is often used as an estimate of a body's surface temperature when the body's emissivity curve (as a function of wavelength) is not known. When the star's or planet's net emissivity in the relevant wavelength band is less than unity (less than that of a black body), the actual temperature of the body will be higher than the effective temperature. The net emissivity may be low due to surface or atmospheric properties, including greenhouse effect. Star The effective temperature of a star is the temperature of a black body with the same luminosity per ''surface area'' () as the star and is defined according to the Stefan–Boltzmann law . Notice that the total (bolometric) luminosity of a star is then , where is the stellar radius. The definition of the stellar radius is obviously not straightf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a convenient short term for ''"all elements except hydrogen and helium"''. This word-use is distinct from the conventional chemical or physical definition of a metal as an electrically conducting solid. Stars and nebulae with relatively high abundances of heavier elements are called "metal-rich" in astrophysical terms, even though many of those elements are nonmetals in chemistry. The presence of heavier elements hails from stellar nucleosynthesis, where the majority of elements heavier than hydrogen and helium in the Universe (''metals'', hereafter) are formed in the cores of stars as they evolve. Over time, stellar winds and supernovae deposit the metals into the surrounding environment, enriching the interstellar medium and providing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Radius
Solar radius is a unit of distance used to express the size of stars in astronomy relative to the Sun. The solar radius is usually defined as the radius to the layer in the Sun's photosphere where the optical depth equals 2/3: :1\,R_ = 6.957\times 10^8 \hbox is approximately 10 times the average radius of Jupiter, about 109 times the radius of the Earth, and 1/215th of an astronomical unit, the distance of the Earth from the Sun. It varies slightly from pole to equator due to its rotation, which induces an oblateness in the order of 10 parts per million. Measurements The unmanned SOHO spacecraft was used to measure the radius of the Sun by timing transits of Mercury across the surface during 2003 and 2006. The result was a measured radius of . Haberreiter, Schmutz & Kosovichev (2008) determined the radius corresponding to the solar photosphere to be . This new value is consistent with helioseismic estimates; the same study showed that previous estimates using inflection poin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Mass
The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass of the Sun. This equates to about two nonillion (short scale), two quintillion (long scale) kilograms or 2000 quettagrams: The solar mass is about times the mass of Earth (), or times the mass of Jupiter (). History of measurement The value of the gravitational constant was first derived from measurements that were made by Henry Cavendish in 1798 with a torsion balance. The value he obtained differs by only 1% from the modern value, but was not as precise. The diurnal parallax of the Sun was accurately measured during the transits of Venus in 1761 and 1769, yielding a value of (9 arcseconds, compared to the present value of ). From the value of the diurnal parallax, one can determine the distance to the Sun from the geometry o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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