DH Tauri
Star in the constellation Taurus
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DH Tauri, also known as DH Tau, is a type M star, located 140 parsecs (456.619 light years) away. It forms a binary system with DI Tauri 15″ away, and has a substellar companion, either a brown dwarf or massive exoplanet.
DH Tauri and the b companion (lower left) with the Very Large Telescope Credit: ESO VLT SPHERE; Van Holstein et al.; Processing: Meli_thev | |
| Observation data Epoch J2000.0 Equinox ICRS | |
|---|---|
| Constellation | Taurus |
| DI Tauri | |
| Right ascension | 04h 29m 42.472s[1] |
| Declination | +26° 32′ 49.13″[1] |
| DH Tauri | |
| Right ascension | 04h 29m 41.553s[2] |
| Declination | +26° 32′ 58.13″[2] |
| Apparent magnitude (V) | 13.1[3] |
| Characteristics | |
| Evolutionary stage | pre-main sequence[4] |
| Spectral type | M0-M1Ve(T)[5] |
| Variable type | T Tau[5] |
| Astrometry | |
| Proper motion (μ) | RA: 6.603[2] mas/yr Dec.: −20.871[2] mas/yr |
| Parallax (π) | 7.4936±0.0255 mas[2] |
| Distance | 435 ± 1 ly (133.4 ± 0.5 pc) |
| Details | |
| DI Tauri | |
| Radius | 1.21[6] R☉ |
| Luminosity | 0.357[6] L☉ |
| Temperature | 4,058[6] K |
| DH Tauri | |
| Mass | 0.41[7] M☉ |
| Radius | 1.26[7] R☉ |
| Luminosity | 0.22[7] L☉ |
| Temperature | 3,751[8] K |
| Age | 3.16[7] Myr |
| Other designations | |
| DH Tau, WDS J04297+2633B, IRAS 04267+2626, 2MASS J04294155+2632582 | |
| Database references | |
| SIMBAD | data |
Characteristics
DH Tauri is a type M, or red dwarf star, one of the most common types of star in the Milky Way.[9] It has an apparent magnitude of 13.71 and temperature of 3,751 K. DH Tauri has a mass of 0.41 M☉ and an estimated radius of 1.26 R☉, which is unusually large for a red dwarf.
The companion DH Tauri B or b has a mass estimated to be between eight MJ and 50 MJ, making it either a super-Jupiter or brown dwarf.[10][11] Other sources give a mass as high as 0.03 M☉, with a bolometric luminosity of 0.01 L☉.[12] The spectral type has been classified as M7.5[12] or M9.25.[13] The companion has detected water vapor and carbon monoxide in its atmosphere and has a rotational velocity of 9.6 ± 0.7 km/s. This is between 9 and 15% of the breakup speed of DH Tau B. This low rotation is in agreement with magnetic coupling to a circumplanetary disk in the late stages of accretion, which reduces angular momentum of the companion.[10] The companion, while its host star still having a protoplanetary disk, is still accreting material, being surrounded by a circumsubstellar disk (possibly a circumplanetary disk, depending on its formation history).[14] It is potentially orbited by a smaller candidate companion DH Tauri Bb (possibly an exomoon) with 1 MJ, and a mass ratio with respect to the brown dwarf of one-tenth.[15]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination (°) |
Radius |
|---|---|---|---|---|---|---|
| b | 8.4±1.1,[16] 11.3±2.2[17] MJ | 234+100 −41[17] |
— | 0.58+0.32 −0.26[17] |
— | 2.51±0.16[16] RJ |