V830 Tauri is a T Tauri star located 425.2 light-years (130.4 pc) away from the Sun in the constellation Taurus.[6] This star is very young, with an age of only 2 million years,[6][7] compared to the Sun's age, which is 4.6 billion years. Typical for a young stars, it exhibits strong flare activity, with three flares detected during a 91-day observation period in 2016.[8]
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 33m 10.03006s[2] |
| Declination | +24° 33′ 43.2555″[2] |
| Apparent magnitude (V) | 12.08 - 12.37[3] |
| Characteristics | |
| Evolutionary stage | T Tau[4] |
| Spectral type | M0-1[5] |
| Variable type | BY Dra[3] |
| Astrometry | |
| Radial velocity (Rv) | 5.98±11.60[2] km/s |
| Proper motion (μ) | RA: 7.171±0.022 mas/yr[2] Dec.: −21.197±0.017 mas/yr[2] |
| Parallax (π) | 7.6704 ± 0.0165 mas[2] |
| Distance | 425.2 ± 0.9 ly (130.4 ± 0.3 pc) |
| Details[4] | |
| Mass | 1.00±0.05 M☉ |
| Radius | 2.0±0.2 R☉ |
| Luminosity | 1.2 L☉ |
| Temperature | 4,250±50 K |
| Rotation | 2.741 days |
| Rotational velocity (v sin i) | 30.5±0.5 km/s |
| Age | ~2 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
Characteristics
editV830 Tauri is an M-type star.[6] The star has a mass of roughly 1 solar mass, but has a radius of 2 solar radii,[6][7] due to the star's age, which means that it hasn't fully contracted yet to become a main-sequence star. (It will likely be on the main sequence portion of its lifetime for about 10 billion years, much like the Sun.) It has a surface temperature of 4,250 K.[6][7] For comparison, the Sun's surface temperature is 5,772 K.
V830 Tauri is a weak-lined T Tauri star, a pre-main sequence star that has a surrounding disc producing emission lines in its spectrum.[4] It is also classified as a BY Draconis variable, cool stars with starspots and chromospheric activity that vary in brightness as they rotate.[3] The variable period of 2.74 days matches the rotation period.[4]
Planetary system
edit| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (controversial) | 0.77±0.15 MJ | 0.057±0.001 | 4.93±0.05 | 0 | 55° | — |
On June 20, 2016, an exoplanet was found around V830 Tauri via radial velocity.[6][7] It is one of, if not the youngest exoplanet ever found, with an age of only about 2 million years.[9][10][11] The exoplanet has a mass of about 0.77 masses of Jupiter and is orbiting 0.057 AU away from its host star with a period of 4.93 d and an inclination of 55°.[6][7] However, a 2020 study was unable to confirm this planet.[12][13][note 1]
V830 Tauri b orbits its parent star every 4.93 days at a distance of 0.057 AU from its parent star.[14] This is about 7x closer to the host star than the planet Mercury is to the Sun. Its mass is about 70% that of Jupiter, and, because it is orbiting very close to its parent star, it is classified as a hot Jupiter.
Previously, before the discovery of V830 Tauri b (and a slightly older planet named K2-33b, with an age around 5-10 million years), TW Hya b was discovered and disproven and PTFO 8-8695 b / CVSO 30 b was discovered with an age equally young and an orbit even closer. The yet unconfirmed objects are pending confirmation.[4] The discovery of V830 Tauri b, K2-33b and PTFO 8-8695 b / CVSO 30 b suggests that the formation and migration of close-in giant planets can occur on a timescale of only a few million years. The new discoveries support planet-disc interactions as the most likely mechanism for efficiently producing young hot Jupiters.[4]
Notes
edit- ^ Works by Donati claims to detect 0.068km/s radial-velocity planetary signal embedded within 1.2km/s jitter, based only on 27 radial-velocity measurements.
References
edit- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 8 December 2021.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c Samus, N. N.; Durlevich, O. V.; et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 1. Bibcode:2009yCat....102025S.
- ^ a b c d e f g Donati, J. F.; Moutou, C.; Malo, L.; Baruteau, C.; Yu, L.; Hébrard, E.; Hussain, G.; Alencar, S.; Ménard, F.; Bouvier, J.; Petit, P.; Takami, M.; Doyon, R.; Cameron, A. Collier (2016). "A hot Jupiter orbiting a 2-million-year-old solar-mass T Tauri star". Nature. 534 (7609): 662–6. arXiv:1606.06236. Bibcode:2016Natur.534..662D. doi:10.1038/nature18305. PMID 27324847. S2CID 1046761.
- ^ Strassmeier, Klaus G. (2009). "Starspots". The Astronomy and Astrophysics Review. 17 (3): 251–308. Bibcode:2009A&ARv..17..251S. doi:10.1007/s00159-009-0020-6.
- ^ a b c d e f g "The Extrasolar Planet Encyclopaedia — V830 Tau b". Extrasolar Planets Encyclopaedia. Retrieved 2017-07-30.
- ^ a b c d e "V830 Tau b". exoplanetarchive.ipac.caltech.edu. Retrieved 2017-07-30.
- ^ Donati, J.-F.; Yu, L.; Moutou, C.; Cameron, A. C.; Malo, L.; Grankin, K.; Hébrard, E.; Hussain, G. A. J.; Vidotto, A. A.; Alencar, S. H. P.; Haywood, R. D.; Bouvier, J.; Petit, P.; Takami, M.; Herczeg, G. J.; Gregory, S. G.; Jardine, M. M.; Morin, J.; the MaTYSSE collaboration (2016), "The hot Jupiter of the magnetically active weak-line T Tauri star V830 Tau", Monthly Notices of the Royal Astronomical Society, 465 (3): 3343–3360, arXiv:1611.02055, doi:10.1093/mnras/stw2904
- ^ Newborn Giant Planet Grazes its Sun, IRAP / OMP Press Release, 2016 Jun 20
- ^ "'Hot Jupiter' planet orbiting newborn star surprises scientists" CBC News http://www.cbc.ca/news/technology/hot-jupiter-1.3419412
- ^ "Discovery of 'baby' planets sheds light on planet and solar system formation" The Guardian
- ^ Damasso, M.; et al. (October 2020). "The GAPS Programme at TNG. XXVII. Reassessment of a young planetary system with HARPS-N: is the hot Jupiter V830 Tau b really there?". Astronomy & Astrophysics. 642: A133. arXiv:2008.09445. Bibcode:2020A&A...642A.133D. doi:10.1051/0004-6361/202038864.
- ^ Planet V830 Tau b on exoplanet.eu
- ^ "V830 Tauri b". Retrieved 2016-06-22.