78 relations: Age of the universe, Astronomical unit, Barnard's Star, Big Bang, Blue dwarf (red-dwarf stage), Brown dwarf, Cataclysmic variable star, Celsius, Circumstellar habitable zone, Convection, Convection zone, Earth mass, Effective temperature, Exoplanet, Extraterrestrial (TV documentary), Flare star, Galactic plane, Gliese 229, Gliese 402, Gliese 581, Gliese 581 planetary system, Gliese 581c, Gliese 581d, Gliese 581g, Gravitational microlensing, Habitability of red dwarf systems, Helium, Hertzsprung–Russell diagram, High Accuracy Radial Velocity Planet Searcher, HIP 12961, Hydrogen, Jupiter, K-type main-sequence star, Kapteyn's Star, Kelvin, Kilometre, Lacaille 8760, Lalande 21185, List of nearest stars and brown dwarfs, Luminosity, Main sequence, Metallicity, Milky Way, Nemesis (hypothetical star), Neptune, Nuclear fusion, OGLE-2005-BLG-390L, Opacity (optics), Planetary habitability, Proton–proton chain reaction, ..., Proxima Centauri, Radiation, Red giant, Sky & Telescope, Solar luminosity, Solar mass, Spiral galaxy, Star, Star cluster, Star count, Stéphane Udry, Stellar classification, Stellar evolution, Stellar population, Sun, Super-Earth, Supernova, Thermonuclear fusion, Tidal locking, TRAPPIST-1, TRAPPIST-1e, TRAPPIST-1f, TRAPPIST-1g, Universe, V1054 Ophiuchi, VB 10, White dwarf, Wolf 359. Expand index (28 more) » « Shrink index
In physical cosmology, the age of the universe is the time elapsed since the Big Bang.
The astronomical unit (symbol: au, ua, or AU) is a unit of length, roughly the distance from Earth to the Sun.
Barnard's Star is a very-low-mass red dwarf about 6 light-years away from Earth in the constellation of Ophiuchus.
The Big Bang theory is the prevailing cosmological model for the universe from the earliest known periods through its subsequent large-scale evolution.
A blue dwarf is a predicted class of star that develops from a red dwarf after it has exhausted much of its hydrogen fuel supply.
Brown dwarfs are substellar objects that occupy the mass range between the heaviest gas giant planets and the lightest stars, having masses between approximately 13 to 75–80 times that of Jupiter, or approximately to about.
Cataclysmic variable stars (CV) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state.
The Celsius scale, previously known as the centigrade scale, is a temperature scale used by the International System of Units (SI).
In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.
Convection is the heat transfer due to bulk movement of molecules within fluids such as gases and liquids, including molten rock (rheid).
A convection zone, convective zone or convective region of a star is a layer which is unstable to convection.
Earth mass (where ⊕ is the standard astronomical symbol for planet Earth) is the unit of mass equal to that of Earth.
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.
An exoplanet or extrasolar planet is a planet outside our solar system.
Extraterrestrial (also Alien Worlds in the UK) is a British-American two-part television documentary miniseries, aired in 2005 in the UK by Channel 4, by the National Geographic Channel (as Extraterrestrial) in the US on Monday, May 30, 2005 and produced by Blue Wave Productions Ltd.
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes.
The galactic plane is the plane on which the majority of a disk-shaped galaxy's mass lies.
Gliese 229 (also written as Gl 229 or GJ 229) is a red dwarf about 19 light years away in the constellation Lepus.
Gliese 581 is a star of spectral type M3V (a red dwarf) at the center of the Gliese 581 planetary system, about 20 light years away from Earth in the Libra constellation.
The Gliese 581 planetary system is the gravitationally bound system comprising the star Gliese 581 and the objects that orbit it.
Gliese 581c or Gl 581c is a planet orbiting within the Gliese 581 system.
Gliese 581d (often shortened to Gl 581d or GJ 581d) is a possible extrasolar planet orbiting within the Gliese 581 system, approximately 20.4 light-years away in the Libra constellation.
Gliese 581g, unofficially known as Zarmina (or Zarmina's World), is an unconfirmed (and frequently disputed) exoplanet claimed to orbit within the Gliese 581 system, twenty light-years from Earth.
Gravitational microlensing is an astronomical phenomenon due to the gravitational lens effect.
The habitability of red dwarf systems is determined by a large number of factors from a variety of sources.
Helium (from lit) is a chemical element with symbol He and atomic number 2.
The Hertzsprung–Russell diagram, abbreviated H–R diagram, HR diagram or HRD, is a scatter plot of stars showing the relationship between the stars' absolute magnitudes or luminosities versus their stellar classifications or effective temperatures.
The High Accuracy Radial velocity Planet Searcher (HARPS) is a high-precision echelle planet finding spectrograph installed in 2002 on the ESO's 3.6m telescope at La Silla Observatory in Chile.
HIP 12961 is a dim red dwarf star located approximately 75 light-years away in the constellation of Eridanus.
Hydrogen is a chemical element with symbol H and atomic number 1.
Jupiter is the fifth planet from the Sun and the largest in the Solar System.
A K-type main-sequence star (K V), also referred to as an orange dwarf or K dwarf, is a main-sequence (hydrogen-burning) star of spectral type K and luminosity class V. These stars are intermediate in size between red M-type main-sequence stars ("red dwarfs") and yellow G-type main-sequence stars.
Kapteyn's Star is a class M1 red subdwarf about 12.76 light years from Earth in the southern constellation Pictor; it is the closest halo star to the Solar System.
The Kelvin scale is an absolute thermodynamic temperature scale using as its null point absolute zero, the temperature at which all thermal motion ceases in the classical description of thermodynamics.
The kilometre (International spelling as used by the International Bureau of Weights and Measures; SI symbol: km; or) or kilometer (American spelling) is a unit of length in the metric system, equal to one thousand metres (kilo- being the SI prefix for). It is now the measurement unit used officially for expressing distances between geographical places on land in most of the world; notable exceptions are the United States and the road network of the United Kingdom where the statute mile is the official unit used.
Lacaille 8760 (AX Microscopii) is a red dwarf star in the constellation Microscopium.
Lalande 21185 is a star in the constellation of Ursa Major, relevant for being the brightest red dwarf observable in the northern hemisphere (only AX Microscopii and Lacaille 9352, in the southern hemisphere, are brighter).
The following two lists include all the known stars and brown dwarfs that are within of the Sun, or were/will be within in the astronomically near past or future.
In astronomy, luminosity is the total amount of energy emitted per unit of time by a star, galaxy, or other astronomical object.
In astronomy, the main sequence is a continuous and distinctive band of stars that appear on plots of stellar color versus brightness.
In astronomy, metallicity is used to describe the abundance of elements present in an object that are heavier than hydrogen or helium.
The Milky Way is the galaxy that contains our Solar System.
Nemesis is a hypothetical red dwarf or brown dwarf, originally postulated in 1984 to be orbiting the Sun at a distance of about 95,000 AU (1.5 light-years), somewhat beyond the Oort cloud, to explain a perceived cycle of mass extinctions in the geological record, which seem to occur more often at intervals of 26 million years.
Neptune is the eighth and farthest known planet from the Sun in the Solar System.
In nuclear physics, nuclear fusion is a reaction in which two or more atomic nuclei come close enough to form one or more different atomic nuclei and subatomic particles (neutrons or protons).
OGLE-2005-BLG-390L is a star thought to be a spectral type M (a red dwarf; 95% probability, 4% probability it is a white dwarf,.
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light.
Planetary habitability is the measure of a planet's or a natural satellite's potential to have habitable environments hospitable to life, or its ability to generate life endogenously.
The proton–proton chain reaction is one of the two (known) sets of fusion reactions by which stars convert hydrogen to helium.
Proxima Centauri, or Alpha Centauri C, is a red dwarf, a small low-mass star, about from the Sun in the constellation of Centaurus.
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium.
A red giant is a luminous giant star of low or intermediate mass (roughly 0.3–8 solar masses) in a late phase of stellar evolution.
Sky & Telescope (S&T) is a monthly American magazine covering all aspects of amateur astronomy, including the following.
The solar luminosity,, is a unit of radiant flux (power emitted in the form of photons) conventionally used by astronomers to measure the luminosity of stars, galaxies and other celestial objects in terms of the output of the Sun.
The solar mass is a standard unit of mass in astronomy, equal to approximately.
Spiral galaxies form a class of galaxy originally described by Edwin Hubble in his 1936 work The Realm of the Nebulae(pp. 124–151) and, as such, form part of the Hubble sequence.
A star is type of astronomical object consisting of a luminous spheroid of plasma held together by its own gravity.
Star clusters are groups of stars.
Star counts are bookkeeping surveys of stars and the statistical and geometrical methods used to correct the survey data for bias.
Stéphane Udry (born 1961 in Sion, Switzerland) is an astronomer at the Geneva Observatory in Switzerland, whose current work is primarily the search for extra-solar planets.
In astronomy, stellar classification is the classification of stars based on their spectral characteristics.
Stellar evolution is the process by which a star changes over the course of time.
During 1944, Walter Baade categorized groups of stars within the Milky Way into bluer stars associated with the spiral arms and the general position of yellow stars near the central galactic bulge or within globular star clusters.
The Sun is the star at the center of the Solar System.
A super-Earth is an extrasolar planet with a mass higher than Earth's, but substantially below the masses of the Solar System's ice giants, Uranus and Neptune, which have masses of 15 and 17 times Earth's, respectively.
A supernova (plural: supernovae or supernovas, abbreviations: SN and SNe) is a transient astronomical event that occurs during the last stellar evolutionary stages of a star's life, either a massive star or a white dwarf, whose destruction is marked by one final, titanic explosion.
Thermonuclear fusion is a way to achieve nuclear fusion by using extremely high temperatures.
Tidal locking (also called gravitational locking or captured rotation) occurs when the long-term interaction between a pair of co-orbiting astronomical bodies drives the rotation rate of at least one of them into the state where there is no more net transfer of angular momentum between this body (e.g. a planet) and its orbit around the second body (e.g. a star); this condition of "no net transfer" must be satisfied over the course of one orbit around the second body.
TRAPPIST-1, also designated as 2MASS J23062928-0502285, is an ultra-cool red dwarf star that is slightly larger, but much more massive, than the planet Jupiter; it is located from the Sun, in the direction described as the constellation Aquarius.
TRAPPIST-1e, also designated as 2MASS J23062928-0502285 e, is a solid, almost Earth-sized exoplanet orbiting within the habitable zone around the ultracool dwarf star TRAPPIST-1 approximately 40 light-years (12.1 parsecs, or nearly km) away from Earth in the constellation of Aquarius.
TRAPPIST-1g, also designated as 2MASS J23062928-0502285 g, is an exoplanet orbiting around the ultra-cool dwarf star TRAPPIST-1 away from Earth in the constellation Aquarius.
The Universe is all of space and time and their contents, including planets, stars, galaxies, and all other forms of matter and energy.
V1054 Ophiuchi, together with the star Gliese 643, is a nearby quintuple star system, in constellation Ophiuchus at 21.05 light-years.
VB 10 or Van Biesbroeck's star is a very small and very dim red dwarf located in the constellation Aquila.
A white dwarf, also called a degenerate dwarf, is a stellar core remnant composed mostly of electron-degenerate matter.
Wolf 359 is a red dwarf star located in the constellation Leo, near the ecliptic.