Discovery [1] | |
---|---|
Discovered by |
|
Discovery date | 2012 |
Direct imaging | |
Physical characteristics | |
Mass | 4–7 Jupiter masses |
Temperature | ~700 K |
Spectral type | T7 |
CFBDSIR 2149-0403 (full designation CFBDSIR J214947.2-040308.9) is a free-floating planetary-mass object or possibly a high-metallicity, low-mass brown dwarf in the constellation Aquarius. Originally, it was thought to be part of the AB Doradus moving group (ABDMG) as indicated by its position and proper motion, [1] [2] but the same team that discovered the object and conjectured its membership in the group has now rejected that hypothesis due to newer measurements. Without that membership, the age and mass of the object cannot be constrained. [3] There is insufficient evidence to demonstrate that CFBDSIR 2149-0403 formed as a planet and was subsequently ejected.[ citation needed ]
CFBDSIR 2149-0403 was discovered by the Canada-France Brown Dwarfs Survey, a near-infrared sky survey, and confirmed by WISE data. [1] Philippe Delorme, of the Institute of Planetology and Astrophysics of Grenoble in France and his team, including researchers at Université de Montréal in Canada, detected CFBDSIR2149's infrared signature using the Canada-France-Hawaii Telescope. They then examined the body's properties with the European Southern Observatory's Very Large Telescope in Chile.
If this object is actually a rogue planet (which has not been decisively demonstrated), then it is among the closest that has ever been spotted. [4] If the object belongs to the ABDMG then its distance is estimated to be 40±4 parsecs (130±13 light-years) from Earth; other possible estimates range from 25 to 50 parsecs. [1] The closest confirmed rogue planet is PSO J318.5-22. [5]
In the discovery paper, CFBDSIR 2149-0403 was claimed to possibly be a kinematic member of the AB Doradus moving group (ABDMG). The ABDMG appears to be similar in age to the Pleiades, [6] which has a lithium-depletion boundary age of 130±20 Myr. [7] If CFBDSIR2149 is indeed associated with the ABDMG, then it is similarly young. However, with Delorme's team now rejecting that hypothesis, estimates are either under 500 million years as a rogue planet with mass between 2 and 13 Jupiter masses, or else a two- to three-billion-year-old brown dwarf with mass between 2 and 40 Jupiter masses. The object shows signs of low gravity (brighter K band in the near-infrared), which could be attributable to youth.
Spectroscopy observations have found light absorption by gaseous methane and water in the object's atmosphere. [1]
Brown dwarfs are substellar objects that have more mass than the biggest gas giant planets, but less than the least massive main-sequence stars. Their mass is approximately 13 to 80 times that of Jupiter (MJ)—not big enough to sustain nuclear fusion of ordinary hydrogen (1H) into helium in their cores, but massive enough to emit some light and heat from the fusion of deuterium (2H). The most massive ones can fuse lithium (7Li).
A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf.
54 Piscium is an orange dwarf star approximately 36 light-years away in the constellation of Pisces. In 2003, an extrasolar planet was confirmed to be orbiting the star, and in 2006, a brown dwarf was also discovered orbiting it.
2M1207b is a planetary-mass object orbiting the brown dwarf 2M1207, in the constellation Centaurus, approximately 170 light-years from Earth. It is one of the first candidate exoplanets to be directly observed. It was discovered in April 2004 by the Very Large Telescope (VLT) at the Paranal Observatory in Chile by a team from the European Southern Observatory led by Gaël Chauvin. It is believed to be from 5 to 6 times the mass of Jupiter and may orbit 2M1207 at a distance roughly as far from the brown dwarf as Pluto is from the Sun.
Cha 110913−773444 is an astronomical object surrounded by what appears to be a protoplanetary disk. It lies at a distance of 529 light-years from Earth. There is no consensus yet among astronomers whether to classify the object as a sub-brown dwarf or a rogue planet.
A sub-brown dwarf or planetary-mass brown dwarf is an astronomical object that formed in the same manner as stars and brown dwarfs but that has a planetary mass, therefore by definition below the limiting mass for thermonuclear fusion of deuterium . Some researchers call them rogue planets whereas others call them planetary-mass brown dwarfs.
AB Doradus is a pre-main-sequence quadruple star system in the constellation Dorado. The primary is a flare star that shows periodic increases in activity.
The Beta Pictoris Moving Group is a young moving group of stars located relatively near Earth. A moving group, in astronomy, is a group of stars that share a common motion through space as well as a common origin. This moving group is named for Beta Pictoris.
54 Piscium b, occasionally catalogued as 54 Piscium Ab to differentiate from the brown dwarf in the system, is an extrasolar planet approximately 36 light-years away in the constellation of Pisces. It was discovered orbiting the orange dwarf star 54 Piscium. Its minimum mass is one-fifth that of Jupiter, and it orbits the star in a very eccentric orbit about every two months.
AB Doradus Moving Group is a group of about 30 associated stars that are moving through space together with the star AB Doradus. A moving group is distinguished by its members having about the same age, composition and motion through space. Hence they most likely formed in the same location.
A planetary-mass object (PMO), planemo, or planetary body is, by geophysical definition of celestial objects, any celestial object massive enough to achieve hydrostatic equilibrium, but not enough to sustain core fusion like a star.
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PSO J318.5−22 is an extrasolar object of planetary mass that does not orbit a parent star, it is an analog to directly imaged young gas giants. There is no consensus yet among astronomers whether the object should be referred to as a sub-brown dwarf, as a rogue planet or as a young brown dwarf. It is approximately 80 light-years away and belongs to the Beta Pictoris moving group. The object was discovered in 2013 in images taken by the Pan-STARRS PS1 wide-field telescope. PSO J318.5-22's age is inferred to be 23 million years, the same age as the Beta Pictoris moving group. Based on its calculated temperature and age, it is classified under the brown dwarf spectral type L7.
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GU Piscium b (GU Psc b) is a directly imaged planetary-mass companion orbiting the star GU Piscium, with an extremely large orbit of 2,000 AU (3.0×1011 km), and an apparent angular separation of 42 arc seconds. The planet is located at right ascension 01h 12m 36.48s declination +17° 04′ 31.8″ at a distance of 48 pc (160 ly).
51 Eridani is a star in the constellation Eridanus. It has an apparent magnitude of 5.22, meaning it is just visible to the unaided eye in suburban and rural skies. The primary star's absolute magnitude is 2.87. There is also a binary star named GJ 3305 which shares the same proper motion through space with it, making it overall a triple star system.
2MASS J11193254–1137466 AB is a planetary mass binary located 86±23 light-years from the Earth in the constellation Crater. The components of 2MASS J1119–1137 are each roughly four Jupiter masses. The planetary-mass objects are probably a part of the TW Hydrae association which has an age of approximately 10 million years. The planetary-mass objects are candidate rogue planets.
Delorme 1 is a binary star with a planetary-mass companion (PMC) or protoplanet in a circumbinary orbit. The PMC is notable for showing signs of accretion, despite being 30-45 Myr old, making it similar to Peter Pan disks. These disks show characteristics of a gas-rich disk at unexpected high ages.