Wolf 1130

Wolf 1130 AB, C

unWISE image of the triple Wolf 1130 AB (center) and C (lower left in the yellow circle)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Cygnus
Wolf 1130 AB
Right ascension 20h 05m 02.1951s
Declination +54° 26′ 03.234″
Apparent magnitude (V) 13.883±0.007
Wolf 1130 C
Right ascension 20h 05m 20.7785s
Declination +54° 24′ 43.274″
Characteristics
Wolf 1130 AB
Evolutionary stage subdwarf + white dwarf
Spectral type M3+WD
Variable type Flare star
Wolf 1130 C
Evolutionary stage brown dwarf
Spectral type (e)sdT6:
Astrometry
Wolf 1130AB
Proper motion (μ) RA: −1,159.524 mas/yr
Dec.: −904.008 mas/yr
Parallax (π)60.2958±0.0266 mas
Distance54.09 ± 0.02 ly
(16.585 ± 0.007 pc)
Absolute magnitude (MV)10.99
Wolf 1130C
Proper motion (μ) RA: −1,156.2 mas/yr
Dec.: −904.4 mas/yr
Parallax (π)53.9±2.7 mas
Distance61 ± 3 ly
(18.6 ± 0.9 pc)
Orbit
PrimaryWolf 1130A
NameWolf 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
Mass0.26 M
Radius0.33 R
Surface gravity (log g)4.9 cgs
Temperature3,530±60 K
Metallicity [Fe/H]−0.70±0.12 dex
B
Mass1.24+0.19
−0.15
 M
Radius0.005 R
Temperature<7000 K
C
Mass44+6
−5
 MJup
Radius0.80±0.02 RJup
Luminosity (bolometric)10−6.047±0.003 L
Surface gravity (log g)5.19+0.05
−0.06
 cgs
Temperature621±9 K
Metallicity−0.68±0.04 dex
Other designations
HIP 98906, WDS J20050+5426, 2MASS J20050227+5426037, GJ 781, LHS 482, WISEA J200500.79+542553.7, WISE J200520.38+542433.9
Database references
SIMBADWolf 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). 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. This makes Wolf 1130C one of the oldest brown dwarfs known to science, together with LSPM J0055+5948B, which has a similar age. There might be older brown dwarfs, such as WISE 1534–1043, which have less well determined ages.