Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cygnus |
Wolf 1130 AB | |
Right ascension | 20h 05m 02.1951s [1] |
Declination | +54° 26′ 03.234″ [1] |
Apparent magnitude (V) | 13.883 ± 0.007 |
Wolf 1130 C | |
Right ascension | 20h 05m 20.38s [2] |
Declination | +54° 24′ 33.9″ [2] |
Characteristics | |
Spectral type | sdM3+ONe+(e)sdT6: [3] [4] |
Variable type | Flare star [5] |
Astrometry | |
Wolf 1130AB | |
Proper motion (μ) | RA: −01159.524 mas/yr [1] Dec.: −0904.008 mas/yr [1] |
Parallax (π) | 60.2958 ± 0.0266 mas [1] |
Distance | 54.09 ± 0.02 ly (16.585 ± 0.007 pc) |
Orbit [3] [6] | |
Primary | Wolf 1130A |
Companion | Wolf 1130B |
Period (P) | 0.497±0.003 d |
Semi-major axis (a) | ca. 3 R☉ |
Eccentricity (e) | 0.011±0.003 |
Inclination (i) | 29±3° |
Longitude of the node (Ω) | 210±19° |
Details | |
A | |
Mass | 0.26 [6] M☉ |
Radius | 0.33 [6] R☉ |
Surface gravity (log g) | 4.9 [3] cgs |
Temperature | 3,530±60 [3] K |
Metallicity [Fe/H] | −0.70±0.12 [3] dex |
B | |
Mass | 1.24+0.19 −0.15 [3] M☉ |
Radius | 0.005 [3] R☉ |
Temperature | <7000 [3] K |
C | |
Mass | 44.9 [7] MJup |
Radius | 0.82 [7] RJup |
Temperature | 647 [7] K |
Metallicity | −0.65+0.10 −0.07 dex [4] |
Other designations | |
Database references | |
SIMBAD | Wolf 1130AB |
Wolf 1130C |
Wolf 1130 is a nearby pre-cataclysmic triple star system consisting of a cold subdwarf of spectral type sdM3 (A), an ultramassive white dwarf (B) and a cold brown dwarf of spectral type sdT8 (C). [3] Wolf 1130 is 54.1 light-years (16.6 parsecs) distant from earth.
The system is older than 10 billion years based on UVW velocities and the low metallicity of Wolf 1130A. [3] This makes Wolf 1130C one of the oldest brown dwarfs known to science, together with LSPM J0055+5948B, which has a similar age. [8] There might be older brown dwarfs, such as WISE 1534–1043, which have less well determined ages.
Wolf 1130A is a subdwarf of spectral type sdM3 [3] with a mass of about 0.26 M☉ and a radius of 0.33 R☉. Wolf 1130A and B are tidally locked, deforming Wolf 1130A into an ellipsoid shape. The radius of Wolf 1130A is inflated up to 20% due to rapid rotation in the tidally locked system. [3] [6] Wolf 1130A has a low metallicity of about [Fe/H]=−0.7 dex. [3]
Wolf 1130B is an ultramassive white dwarf with a mass of about 1.24 M☉ and it remains invisible to telescopic observations. [3] The progenitor of the white dwarf had a mass of about 6 to 8 M☉. This progenitor probably spent between 50 and 100 million years in the main-sequence before it became a giant star and engulfed Wolf 1130A in a common envelope. [3] Because of its high mass, the white dwarf Wolf 1130B is suspected to consist of oxygen, magnesium and neon (an ONe white dwarf). [3]
Wolf 1130AB is a periodic variable star with a period of 0.497 days and also a flare star, with the variable star designation V1513 Cygni. The flares occur due to material being occasionally accreted onto the surface of the white dwarf. [6] Three components cause the variability of Wolf 1130A: [3]
In the future the system will lose orbital energy due to effects such as magnetic braking and by emitting gravitational waves. Wolf 1130A will get close to the Roche radius of Wolf 1130B in about 6.2 billion years. At this point the system will transfer mass from the M-type subdwarf to the surface of the white dwarf, becoming a cataclysmic variable. Once the mass transfer starts, magnetic braking will gain strength, and after less than 500 million years the Wolf 1130AB pair will merge. This merger could produce a type Ia supernova. The resulting merger would be near or above the Chandrasekhar limit. [3]
The outer companion Wolf 1130C (WISE J200520.38+542433.9) was discovered in 2013. [10] It has a temperature of 647 K (374 °C, 705 °F), a radius of 0.82 RJ and a mass of 44.9 MJ. [7] The brown dwarf has a low metallicity which causes an unusually low luminosity compared to other stars of the same mass, and it is therefore classified as a subdwarf. It is suspected that it orbited Wolf 1130AB in a closer orbit when Wolf 1130B was still a main-sequence star. When Wolf 1130AB became a common-envelope binary and Wolf 1130B later a white dwarf, the entire system lost 80% of its mass and forced Wolf 1130C into a more distant orbit of 3150 astronomical units. [3] New classification of T-type subdwarfs found a metallicity of [M/H]=−0.65+0.10
−0.07 dex, using SAND-models. This is consistent with the metallicity of the host star. The researchers classify this object as an (e)sdT6:, meaning it is between normal subdwarfs and extreme subdwarfs and the colon indicates an uncertain spectral classification. [4]
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 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 than that of main-sequence stars of the same spectral type. On a Hertzsprung–Russell diagram subdwarfs appear to lie below the main sequence.
2MASS J05325346+8246465 is possibly the first brown dwarf observed in the galactic halo of the Milky Way, and the first known substellar subdwarf star. It was discovered from Two Micron All-Sky Survey data, and verified by observations at Palomar Observatory and W. M. Keck Observatory. It has a low metallicity, which indicates it is an old star.
An object with the spectral type T is either a brown dwarf or young free-floating planetary-mass object. An directly imaged exoplanet with a young age can also be a T-dwarf. T dwarfs are colder than L dwarfs, but warmer than Y dwarfs.
An object with the spectral type L can be either a low-mass star, a brown dwarf or a young free-floating planetary-mass object. If a young exoplanet or planetary-mass companion is detected via direct imaging, it can also have an L spectral type, such as Kappa Andromedae b.
An object with a spectral type Y is either a brown dwarf or a free-floating planetary-mass object. They have temperatures below around 500 Kelvin and are colder than T-dwarfs. Y-dwarfs have a similar spectrum when compared to the giant planet Jupiter.
WISEPC J045853.90+643451.9 is a binary system of two ultracool brown dwarfs of spectral classes T8.5 and T9.5, respectively, located in constellation Camelopardalis at approximately 47 ly from Earth.
WISEPA J173835.53+273258.9 is a brown dwarf of spectral class Y0, located in the constellation Hercules at 24.9 light-years from Earth.
WISE J004945.61+215120.0 is a brown dwarf of spectral class T8.5, located in constellation Andromeda at approximately 24 light-years from Earth.
WISE J031624.35+430709.1 is a brown dwarf of spectral class T8, located in constellation Perseus at approximately 106 light-years from Earth. It was one of the furthest T-class brown dwarfs known. In 2024 a T dwarf about 2 kpc distant, with a low-metallicity was discovered with the JWST. This brown dwarf is called JADES-GS-BD-9. Additional kpc distant T dwarfs were discovered by two teams, with UNCOVER-BD-1 being 4.5 or 4.8 kpc distant.
2MASS J15031961+2525196 is a nearby brown dwarf of spectral type T5.5, located in the constellation of Boötes at approximately 20.7 light-years from Earth. It was discovered in 2003 by Adam J. Burgasser et al. in wide-field search for T dwarfs using the Two Micron All Sky Survey (2MASS).
2MASS J15404341−5101357 is a red dwarf of spectral type M7, located in Norma at approximately 17 light-years from Earth. It is the nearest known M7 dwarf.
Backyard Worlds: Planet 9 is a NASA-funded citizen science project which is part of the Zooniverse web portal. It aims to discover new brown dwarfs, faint objects that are less massive than stars, some of which might be among the nearest neighbors of the Solar System, and might conceivably detect the hypothesized Planet Nine. The project's principal investigator is Marc Kuchner, an astrophysicist at NASA's Goddard Space Flight Center.
2MASS J11263991−5003550(2MASS J1126−5003) is a brown dwarf about 53 light-years distant from earth. The brown dwarf is notable for an unusual blue near-infrared color. This brown dwarf does not show subdwarf features and the blue color cannot be explained by an unresolved binary. Instead the blue color is explained by patchy clouds. The patchy cloud model allows thick clouds and a cloud coverage of 50% to explain the spectra of 2MASS J1126−5003. Other blue L-dwarfs exist, but are quite rare.
WISE 1534–1043 is a brown dwarf, Class Y, the coolest class, visible only in the infrared. It was accidentally discovered via the Wide-field Infrared Survey Explorer.
BD+29 5007 is a K-type star, located 77 light-years in the constellation Pegasus. It has a large-separation companion that was identified in 2016. The pair was identified to be a possible member of the 45+15
−5 million years old Argus association, though this is disputed.
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