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Kepler-61b
Kepler-61b (also known by its Kepler Object of Interest designation KOI-1361.01) is a super-Earth exoplanet orbiting within parts of the habitable zone of the K-type main-sequence star Kepler-61. It is located about 1,100 light-years (338 parsecs) from Earth in the constellation of Cygnus. It was discovered in 2013 using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured, by NASA's Kepler spacecraft. Characteristics Mass, radius and temperature Kepler-61b is a super-Earth, an exoplanet with a radius and mass bigger than Earth, but smaller than that of the ice giants Neptune and Uranus. It has an equilibrium temperature of . It has a radius of 2.15 . The mass of Kepler-61b is 6.65 . At 2.15 radius and with a 6.65 mass its density would come to around 3.6 g/cm3 or slightly below the 3.9 g/cm3 of Mars. This planet may also have some "volatile" make up or be an ocean planet to explain the lower density. Host star ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler-61
Kepler-61 is a K-type main-sequence star approximately 1,100 light years from Earth in the constellation Cygnus. It is located within the field of vision of the Kepler spacecraft, the satellite that NASA's Kepler Mission used to detect planets that may be transiting their stars. On April 24, 2013 it was announced that the star has an extrasolar planet (a super-Earth) orbiting in the inner edge of the habitable zone, named Kepler-61b.Exoplanet Characterization by Proxy: a Transiting 2.15 R_Earth Planet Near the Habitable Zone of the Late K dwarf Kepler-61 Sarah Ballard, David Charbonneau, Francois Fressin, Guillermo Torres, Jonathan Irwin, Jean-Michel Desert, Elisabeth Newton, Andrew W. Mann, David R. Ciardi, Justin R. Crepp, Christoph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Super-Earth
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below those of the Solar System's ice giants, Uranus and Neptune, which are 14.5 and 17 times Earth's, respectively. The term "super-Earth" refers only to the mass of the planet, and so does not imply anything about the surface conditions or habitability. The alternative term "gas dwarfs" may be more accurate for those at the higher end of the mass scale, although " mini-Neptunes" is a more common term. Definition In general, super-Earths are defined by their masses, and the term does not imply temperatures, compositions, orbital properties, habitability, or environments. While sources generally agree on an upper bound of 10 Earth masses (~69% of the mass of Uranus, which is the Solar System's giant planet with the least mass), the lower bound varies from 1 or 1.9 to 5, with various other definitions appearing in the popular media. The term "super-Earth" is also used by astronomers t ... [...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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoplanets Discovered In 2013
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] |
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] |
1304
Year 1304 ( MCCCIV) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * Battle of Skafida: Emperor Michael IX (Palaiologos) sends a Byzantine expeditionary force (some 10,000 men) to halt the expansion of the Bulgarians in Thrace. The two armies meet near Sozopol on the Bulgarian Black Sea Coast. During the battle, the Bulgarian army led by Tsar Theodore Svetoslav is defeated and routed. The Byzantines, infatuated with the chase of the retreating enemy, crowd on a bridge – which possibly is sabotaged, and break down. The Bulgarians capture many Byzantine soldiers and some nobles are held for ransom. Svetoslav secures his territorial gains and stabilizes himself as the sole ruler of the Bulgarian Empire (until 1322). * The Byzantines lose the island of Chios, in the Aegean Sea, to the Genoese under Admiral Benedetto I Zaccaria. He establishes an autonomous lordship and justifies t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kepler Input Catalog
The Kepler Input Catalog (or KIC) is a publicly searchable database of roughly 13.2 million targets used for the Kepler Spectral Classification Program (SCP) and ''Kepler''. Overview The Kepler SCP targets were observed by the 2MASS project as well as Sloan filters, such as the ''griz'' filters. The catalog alone is not used for finding Kepler targets, because only a portion (about 1/3 of the catalog) can be observed by the spacecraft. The full catalog includes up to 21 magnitude, giving 13.2 million targets, but of these only about 6.5 to 4.5 million fall on Kepler's sensors. KIC is one of the few comprehensive star catalogs for a spacecraft's field of view. The KIC was created because no catalog of sufficient depth and information existed for target selection at that time. The catalog includes "mass, radius, effective temperature, log'' (g)'', metallicity, and reddening extinction". An example of a KIC catalog entry is KIC #10227020. Having had transit signals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometer
A photometer is an instrument that measures the strength of electromagnetic radiation in the range from ultraviolet to infrared and including the visible spectrum. Most photometers convert light into an electric current using a photoresistor, photodiode, or photomultiplier. Photometers measure: * Illuminance * Irradiance * Light absorption * Scattering of light *Reflection of light *Fluorescence * Phosphorescence * Luminescence History Before electronic light sensitive elements were developed, photometry was done by estimation by the eye. The relative luminous flux of a source was compared with a standard source. The photometer is placed such that the illuminance from the source being investigated is equal to the standard source, as the human eye can judge equal illuminance. The relative luminous fluxes can then be calculated as the illuminance decreases proportionally to the inverse square of distance. A standard example of such a photometer consists of a piece of paper ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greenhouse Effect
The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly to space, resulting in a warmer planet. Earth's natural greenhouse effect makes life as we know it possible and carbon dioxide plays a significant role in providing for the relatively high temperature on Earth. The greenhouse effect is a process by which thermal radiation from a planetary atmosphere warms the planet's surface beyond the temperature it would have in the absence of its atmosphere.A concise description of the greenhouse effect is given in the ''Intergovernmental Panel on Climate Change Fourth Assessment Report,'' "What is the Greenhouse Effect?FAQ 1.3 – AR4 WGI Chapter 1: Historical Overview of Climate Change Science, IPCC Fourth Assessment Report, Chapter 1, p. 115: "To balance the absorbed incoming olarenergy, the Earth m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentric Habitable Zones
Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (graph theory) of a vertex in a graph * Eccentricity (mathematics), a parameter associated with every conic section Orbital mechanics * Orbital eccentricity, in astrodynamics, a measure of the non-circularity of an orbit * Eccentric anomaly, the angle between the direction of periapsis and the current position of an object on its orbit * Eccentricity vector, in celestial mechanics, a dimensionless vector with direction pointing from apoapsis to periapsis * Eccentric, a type of deferent, a circle or sphere used in obsolete epicyclical systems to carry a planet around the Earth or Sun Other uses in science and technology * Eccentric (mechanism), a wheel that rotates on an axle that is displaced from the focus of the circle described by the wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Flux
In radiometry, radiant flux or radiant power is the radiant energy emitted, reflected, transmitted, or received per unit time, and spectral flux or spectral power is the radiant flux per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. The SI unit of radiant flux is the watt (W), one joule per second (), while that of spectral flux in frequency is the watt per hertz () and that of spectral flux in wavelength is the watt per metre ()—commonly the watt per nanometre (). Mathematical definitions Radiant flux Radiant flux, denoted Φe ('e' for "energetic", to avoid confusion with photometric quantities), is defined as \Phi_\mathrm = \frac :Q_\mathrm = \int_ \mathbf\cdot \hat\mathbf\, dA where *''t'' is the time; *''Q''e is the radiant energy flux of the field out of a closed surface \Sigma; *S is the Poynting vector, representing the current density of radiant energy; *n is the normal vector of a point on \Sigm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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