Pi3 Orionis
Encyclopedia
Pi3 Orionis formally designated Tabit, is a white F-type dwarf star
approximately 26 light-year
s away in the constellation
of Orion
. It is thought that the star may, in fact, be a binary star
system. Though no extrasolar planet
s have been observed around Pi3 Orionis, the star is considered a prime location for planets as small as the Earth
. Pi3 Orionis is the brightest star in the lion's hide (or shield) that Orion is holding.
of spectral type F6V. It has been calculated that the star has 1.2 times the mass of the Sun
, 1.3 times the radius, and 3 times the luminosity
. It is thought that Pi3 Orionis has a companion star, but the purported companion "B" may not in fact be part of the system.
team has set limits to the presence of one or more planets with masses between 0.84 and 46.7 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical unit
s. Thus, so far it appears that an Earth-like planet could easily orbit the star without any complications.
Dwarf star
The term dwarf star refers to a variety of distinct classes of stars.* Dwarf star alone generally refers to any main sequence star, a star of luminosity class V.** Red dwarfs are low-mass main sequence stars....
approximately 26 light-year
Light-year
A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...
s away in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
of Orion
Orion (constellation)
Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky...
. It is thought that the star may, in fact, be a binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system. Though no extrasolar planet
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
s have been observed around Pi3 Orionis, the star is considered a prime location for planets as small as the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
. Pi3 Orionis is the brightest star in the lion's hide (or shield) that Orion is holding.
Stellar components
Pi3 Orionis is a dwarf starDwarf star
The term dwarf star refers to a variety of distinct classes of stars.* Dwarf star alone generally refers to any main sequence star, a star of luminosity class V.** Red dwarfs are low-mass main sequence stars....
of spectral type F6V. It has been calculated that the star has 1.2 times the mass of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
, 1.3 times the radius, and 3 times the luminosity
Luminosity
Luminosity is a measurement of brightness.-In photometry and color imaging:In photometry, luminosity is sometimes incorrectly used to refer to luminance, which is the density of luminous intensity in a given direction. The SI unit for luminance is candela per square metre.The luminosity function...
. It is thought that Pi3 Orionis has a companion star, but the purported companion "B" may not in fact be part of the system.
Hunt for substellar objects
Although a periodicity of 73.26 days has been observed in the star's radial velocity, it seems likely to be bound more to stellar activity than to a planetary object in close orbit. No substellar companion has been detected so far around Pi3 Orionis and the McDonald ObservatoryMcDonald Observatory
The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Fowlkes and Mount Locke in the Davis Mountains of West Texas...
team has set limits to the presence of one or more planets with masses between 0.84 and 46.7 Jupiter masses and average separations spanning between 0.05 and 5.2 astronomical unit
Astronomical unit
An astronomical unit is a unit of length equal to about or approximately the mean Earth–Sun distance....
s. Thus, so far it appears that an Earth-like planet could easily orbit the star without any complications.