Gaia BH3 facts for kids
.jpg) Artist’s impression of Gaia BH3 Credit: ESO/L. Calçada |
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| Observation data Epoch J2016.0 Equinox J2016.0 |
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|---|---|
| Constellation | Aquila |
| Right ascension | 19h 39m 18.72s |
| Declination | +14° 55′ 54.2″ |
| Characteristics | |
| K2 star | |
| Evolutionary stage | K2 |
| Black hole | |
| Evolutionary stage | Stellar black hole |
| Astrometry | |
| Radial velocity (Rv) | -333.2 ±3.4 km/s |
| Proper motion (μ) | RA: -28.317 ±0.067 mas/yr Dec.: -155.221 ±0.111 mas/yr |
| Parallax (π) | 1.6933 ± 0.0164 mas |
| Distance | 1,930 ± 20 ly (591 ± 6 pc) |
| Orbit | |
| Period (P) | 4,253.1±98.5 d |
| Semi-major axis (a) | 16.17 ± 0.27 AU |
| Eccentricity (e) | 0.7291 ±0.0048 |
| Inclination (i) | 110.580 ±0.095° |
| Longitude of the node (Ω) | 136.236 ±0.128° |
| Periastron epoch (T) | JD, TCB 2458177.39 ± 0.88 |
| Argument of periastron (ω) (secondary) |
77.34 ±0.76° |
| Details | |
| K2 | |
| Mass | 0.76±0.05 M☉ |
| Radius | 4.936 ± 0.016 R☉ |
| Surface gravity (log g) | 2.929 ±0.003 cgs |
| Temperature | 5212 ±80 K |
| Metallicity [Fe/H] | -2.56 ± 0.11 dex |
| Black hole | |
| Mass | 32.70±0.82 M☉ |
| Other designations | |
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Gaia BH3, 2MASS J19391872+1455542, Gaia DR3 4318465066420528000, LS II +14 13
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| Database references | |
| SIMBAD | data |
Gaia BH3 (Gaia DR3 4318465066420528000) is a binary system consisting of a metal-poor K2 star and a stellar-mass black hole. Gaia BH3 is located 1926 light years away (590.6±5.8 pc away) in the constellation of Aquila, making it as of 2024[update] the heaviest known black hole system second-closest to Earth. Gaia BH3 is the first black hole discovered from preliminary Gaia DR4 astrometric data.
The black hole and star orbit the system barycentre every 11.6 years, with an orbital distance ranging from 4.5–29 AU. The black hole's mass is 32.70 M☉, the heaviest known stellar black hole in the Milky Way.
The black hole Gaia BH3 is together with Cygnus X-1 the only black hole more massive than about 10 M☉. The mass of Gaia BH3 is quite similar to the mass of merging binary black holes found via gravitational waves. These massive black holes were suspected to be formed by metal-poor stars and the fact that Gaia BH3 has a metal-poor companion strengthens this conclusion.
Discovery
Gaia BH3 was originally found by astrometric observations with Gaia in 2015 and became a black hole binary candidate by the European Space Agency on 16 April, 2024.
