| |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h33m 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 | |
V830 Tauri, IRAS C04301+2427, 2MASS J04331003+2433433 | |
| Database references | |
| SIMBAD | data |
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]
V830 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]
| 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 periodof4.93 d and an inclinationof55°.[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]
