V723 Monocerotis
Observation data Epoch J2000.0 Equinox J2000.0 | |
---|---|
Constellation | Cetus |
Right ascension | 06h 29m 04.659s[2] |
Declination | −05° 34′ 20.23″[2] |
Apparent magnitude (V) | 8.3[3] |
Characteristics | |
Spectral type | G0II[4] |
Astrometry | |
Proper motion (μ) | RA: −1.513[2] mas/yr Dec.: 15.840[2] mas/yr |
Parallax (π) | 2.175 ± 0.033[1] mas |
Distance | 1,500 ± 20 ly (460 ± 7 pc) |
Orbit[1] | |
Period (P) | 59.9398 d |
Eccentricity (e) | 0 (fixed) |
Inclination (i) | 87.0+1.7 −1.4° |
Argument of periastron (ω) (secondary) | 0 (fixed)° |
Details[1] | |
Giant star | |
Mass | 1.00±0.07 M☉ |
Radius | 24.9±0.7 R☉ |
Luminosity | 173±8 L☉ |
Surface gravity (log g) | 1.7±0.1 cgs |
Temperature | 4,570±60 K |
Metallicity [Fe/H] | −0.9±0.1 dex |
Rotational velocity (v sin i) | 19.1±1 km/s |
Age | 5.4+5.1 −2.6 Gyr |
Dark companion | |
Mass | 3.04±0.06 M☉ |
Radius | 3×10−6 R☉ |
Other designations | |
Database references | |
SIMBAD | data |
V723 Monocerotis is a variable star in the constellation Monoceros. It is proposed to be a binary system including a lower mass gap black hole candidate nicknamed "The Unicorn".[1] Located 1,500 light years from Earth, it may be the closest black hole to our planet, and among the smallest ever found.[6][7]
Located in the Monoceros constellation, V723 Monocerotis is an eighth-magnitude ellipsoidal variable yellow giant star roughly the mass of the Sun, but 25 times its diameter. Its accompanying black hole is believed to have a mass 2.6 times the mass of the Sun, corresponding to a Schwarzschild radius of 7.68 kilometers.[8][9]
See also[]
References[]
- ^ a b c d e Jayasinghe, T.; et al. (2021-01-01). "A unicorn in monoceros: The 3 M⊙ dark companion to the bright, nearby red giant V723 Mon is a non-interacting, mass-gap black hole candidate". Monthly Notices of the Royal Astronomical Society. 504 (2): 2577–2602. arXiv:2101.02212. doi:10.1093/mnras/stab907.
- ^ a b c Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ Høg, E.; Fabricius, C.; Makarov, V. V.; Urban, S.; Corbin, T.; Wycoff, G.; Bastian, U.; Schwekendiek, P.; Wicenec, A. (2000). "The Tycho-2 catalogue of the 2.5 million brightest stars". Astronomy and Astrophysics. 355. Bibcode:2000A&A...355L..27H.
- ^ Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey, 5, Bibcode:1999MSS...C05....0H.
- ^ "V723 Mon". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2021-11-27.
- ^ "Newfound black hole may be the closest to Earth". Science. 2021-04-29. Retrieved 2021-08-09.
- ^ "A black hole dubbed 'the Unicorn' may be galaxy's smallest one". Reuters. 2021-04-22. Retrieved 2021-08-09.
- ^ "Is the "Unicorn" the Closest Black Hole?". Sky & Telescope. 2021-04-23. Retrieved 2021-08-09.
- ^ "Where is the nearest black hole to Earth?". BBC Sky at Night Magazine. Retrieved 2021-08-09.
Further reading[]
- Masuda, Kento; Hirano, Teruyuki (April 2021). "Tidal Effects on the Radial Velocities of V723 Mon: Additional Evidence for a Dark 3 M⊙ Companion". The Astrophysical Journal Letters. 910 (2): 10. arXiv:2103.05216. Bibcode:2021ApJ...910L..17M. doi:10.3847/2041-8213/abecdc. S2CID 232168389. L17.
Categories:
- Monoceros (constellation)
- G-type bright giants
- Stellar black holes
- Binary stars
- Objects with variable star designations
- Hipparcos objects
- Variable star stubs
- Giant-star stubs