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 |
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 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]