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V830 Tau B
V830 Tauri is a T Tauri star located away from the Sun in the constellation Taurus. This star is very young, with an age of only 2 million years, compared to the Sun's age, which is 4.6 billion years. Typical for a young stars, it exhibits a strong flare activity, with three flared detected in 91-days observation period in 2016. Characteristics V830 Tauri is an M-type star. The star has a mass of roughly 1 solar mass, but has a radius of 2 solar radii, due to the star's age, which means that it hasn't fully contracted yet to become a main-sequence star. It has a surface temperature of . For comparison, the Sun's surface temperature is . V830 Tauri is a T Tauri star, a pre-main sequence star that has a surrounding disc producing emission lines in its spectrum. It is classified as a weak-lined T Tauri star. It is also classified as a BY Draconis variable, cool stars with starspots and chromospheric activity that vary in brightness as they rotate. The variable period of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degrees. For a satellite orbiting a planet, the plane of reference is usually the plane containing the planet's equator. For pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
M-type Stars
Type M or M type may refer to: Science and technology * Type M, a xD-Picture Card * Type M, a name for the 15 amp BS 546 electrical plug * Vaio Type M, a kind of Vaio computer from Sony * M-type asteroid * m-type filter, an electronic filter * M-type star * M-types, an implementation of inductive type Other uses * Audi Type M, a 1920s car * Beretta 92FS Compact Type M, a pistol * MG M-type, a sports car See also * M class (other) M class or M-class may refer to: Military * M-class cruiser, a planned German light cruiser class * M-class destroyer, several classes of destroyer ** Admiralty M-class destroyer, a class of British destroyers built 1913–1916 and served in Worl ... * Class M (other) {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IRAS Catalogue Objects
The Infrared Astronomical Satellite (Dutch: ''Infrarood Astronomische Satelliet'') (IRAS) was the first space telescope to perform a survey of the entire night sky at infrared wavelengths. Launched on 25 January 1983, its mission lasted ten months. The telescope was a joint project of the United States (NASA), the Netherlands ( NIVR), and the United Kingdom ( SERC). Over 250,000 infrared sources were observed at 12, 25, 60, and 100 micrometer wavelengths. Support for the processing and analysis of data from IRAS was contributed from the Infrared Processing and Analysis Center at the California Institute of Technology. Currently, the Infrared Science Archive at IPAC holds the IRAS archive. The success of IRAS led to interest in the 1985 Infrared Telescope (IRT) mission on the Space Shuttle, and the planned Shuttle Infrared Telescope Facility which eventually transformed into the Space Infrared Telescope Facility, SIRTF, which in turn was developed into the Spitzer Space Tel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2MASS Objects
Mass is an intrinsic property of a body. It was traditionally believed to be related to the quantity of matter in a physical body, until the discovery of the atom and particle physics. It was found that different atoms and different elementary particles, theoretically with the same amount of matter, have nonetheless different masses. Mass in modern physics has multiple definitions which are conceptually distinct, but physically equivalent. Mass can be experimentally defined as a measure of the body's inertia, meaning the resistance to acceleration (change of velocity) when a net force is applied. The object's mass also determines the strength of its gravitational attraction to other bodies. The SI base unit of mass is the kilogram (kg). In physics, mass is not the same as weight, even though mass is often determined by measuring the object's weight using a spring scale, rather than balance scale comparing it directly with known masses. An object on the Moon would weigh less t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T Tauri Stars
T Tauri stars (TTS) are a class of variable stars that are less than about ten million years old. This class is named after the prototype, T Tauri, a young star in the Taurus star-forming region. They are found near molecular clouds and identified by their optical variability and strong chromospheric lines. T Tauri stars are pre-main-sequence stars in the process of contracting to the main sequence along the Hayashi track, a luminosity–temperature relationship obeyed by infant stars of less than 3 solar masses () in the pre-main-sequence phase of stellar evolution. It ends when a star of or larger develops a radiative zone, or when a smaller star commences nuclear fusion on the main sequence. History While T Tauri itself was discovered in 1852, the T Tauri class of stars were initially defined by Alfred Harrison Joy in 1945. Characteristics T Tauri stars comprise the youngest visible F, G, K and M spectral type stars (). Their surface temperatures are similar to those o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BY Draconis Variables
BY Draconis variables are variable stars of late spectral types, usually K or M, and typically belong to the main sequence. The name comes from the archetype for this category of variable star system, BY Draconis. They exhibit variations in their luminosity due to rotation of the star coupled with starspots, and other chromospheric activity. Resultant brightness fluctuations are generally less than 0.5 magnitudes. Light curves of BY Draconis variables are quasiperiodic. The period is close to the star's mean rotational rate. The light curve is irregular over the duration of the period and it changes slightly in shape from one period to the next. For the star BY Draconis the shape of the light curve over a period remained similar for a month. Nearby K and M stars that are BY Draconis variables include Barnard's Star, Kapteyn's Star, 61 Cygni, Ross 248, Lacaille 8760, Lalande 21185, and Luyten 726-8. Ross 248 is the first discovered BY Draconis variable, the variability having be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pre-main-sequence Stars
A pre-main-sequence star (also known as a PMS star and PMS object) is a star in the stage when it has not yet reached the main sequence. Earlier in its life, the object is a protostar that grows by acquiring mass from its surrounding envelope of interstellar dust and gas. After the protostar blows away this envelope, it is optically visible, and appears on the stellar birthline in the Hertzsprung-Russell diagram. At this point, the star has acquired nearly all of its mass but has not yet started hydrogen burning (i.e. nuclear fusion of hydrogen). The star then contracts, its internal temperature rising until it begins hydrogen burning on the zero age main sequence. This period of contraction is the pre-main sequence stage. An observed PMS object can either be a T Tauri star, if it has fewer than 2 solar masses (), or else a Herbig Ae/Be star, if it has 2 to 8 . Yet more massive stars have no pre-main-sequence stage because they contract too quickly as protostars. By the time ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CVSO 30
CVSO 30 (PTFO 8-8695) is a binary T Tauri star, located in constellation Orion at 1200 light years from Earth away with one candidate planet called CVSO 30 c. The candidate planet is a gas giant. Planetary system CVSO 30 may have one planet called CVSO 30 c. CVSO 30 c is calculated to have a period of 27,000 years and a semimajor axis of 660 AU. Direct imaging of the suspected CVSO 30 c, with a calculated mass equal to 4.7 Jupiter's, has been achieved through photometric and spectroscopic high contrast observations carried out with the Very Large Telescope located in Chile, the Keck Observatory in Hawaii and the Calar Alto Observatory in Spain. However, the colors of the object suggest that it may actually be a background star, such as a K-type giant or a M-type subdwarf A subdwarf, sometimes denoted by "sd", is a star with luminosity class VI under the Yerkes spectral classification system. They are defined as stars with luminosity 1.5 to 2 magnitudes lower th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TW Hydrae
TW Hydrae is a T Tauri star approximately 196 light-years away in the constellation of Hydra (the Sea Serpent). TW Hydrae is about 80% of the mass of the Sun, but is only about 5-10 million years old. The star appears to be accreting from a face-on protoplanetary disk of dust and gas, which has been resolved in images from the ALMA observatory. TW Hydrae is accompanied by about twenty other low-mass stars with similar ages and spatial motions, comprising the "TW Hydrae association" or TWA, one of the closest regions of recent "fossil" star-formation to the Sun. Stellar characteristics TW Hydrae is a pre-main-sequence star that is approximately 80% the mass of and 111% the radius of the Sun. It has a temperature of 4000 K and is about 8 million years old. In comparison, the Sun is about 4.6 billion years old and has a temperature of 5778 K. The star's luminosity is 28% (0.28x) that of the Sun, equivalent to that of a main-sequence star of spectral type ~ K2. However, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
K2-33b
K2-33b (also known by its EPIC designation ''EPIC 205117205.01'') is a very young super-Neptune exoplanet, orbiting the pre-main-sequence star K2-33. It was discovered by NASA's ''Kepler'' spacecraft on its "Second Light" mission. It is located about 456 light-years (140 parsecs) away from Earth in the constellation of Scorpius. The exoplanet was found by using the transit method, in which the dimming effect that a planet causes as it crosses in front of its star is measured. Among known exoplanets, K2-33b is considered extremely young − a mere 9.3 million years old. Only one other exoplanet is younger, with an age of 2 Myr (V830 Tau b). Physical characteristics Mass, radius, and temperature K2-33b is a super-Neptune, an exoplanet that has a mass and radius larger than that of Neptune. It has an equilibrium temperature of . It has a radius of 5.04 . While the exoplanet's mass hasn't been constrained yet, upper estimates place a mass of 3.6 . Atmosphere By 2022, the atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hot Jupiter
Hot Jupiters (sometimes called hot Saturns) are a class of gas giant exoplanets that are inferred to be physically similar to Jupiter but that have very short orbital periods (). The close proximity to their stars and high surface-atmosphere temperatures resulted in their informal name "hot Jupiters". Hot Jupiters are the easiest extrasolar planets to detect via the radial-velocity method, because the oscillations they induce in their parent stars' motion are relatively large and rapid compared to those of other known types of planets. One of the best-known hot Jupiters is . Discovered in 1995, it was the first extrasolar planet found orbiting a Sun-like star. has an orbital period of about 4 days. General characteristics Though there is diversity among hot Jupiters, they do share some common properties. * Their defining characteristics are their large masses and short orbital periods, spanning 0.36–11.8 Jupiter masses and 1.3–111 Earth days. The mass c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
