FU Tauri
 FU Tauri and its companion (lower left) Credit: Image Credit: NASA/ESA/CSA JWST; Ya-Lin Wu et al.; processing: Meli_thev | |
| Observation data Epoch J2000 Equinox ICRS | |
|---|---|
| Constellation | Taurus |
| A | |
| Right ascension | 04h 23m 35.391s |
| Declination | +25° 03′ 02.75″ |
| B | |
| Right ascension | 04h 23m 35.746s |
| Declination | +25° 02′ 59.64″ |
| Characteristics | |
| A | |
| Evolutionary stage | pre-main sequence |
| Spectral type | M7.25 |
| Apparent magnitude (G) | 15.23 + 20.45 |
| Variable type | T Tau |
| B | |
| Evolutionary stage | brown dwarf |
| Spectral type | M9.25 |
| Apparent magnitude (G) | 20.45 |
| Astrometry | |
| A | |
| Radial velocity (Rv) | +19.67±0.01 km/s |
| Proper motion (μ) | RA: +6.901 mas/yr Dec.: −21.252 mas/yr |
| Parallax (π) | 7.8354±0.0754 mas |
| Distance | 416 ± 4 ly (128 ± 1 pc) |
| B | |
| Proper motion (μ) | RA: +1.5 mas/yr Dec.: −24.2 mas/yr |
| Parallax (π) | 7.4750±1.1221 mas |
| Distance | approx. 440 ly (approx. 130 pc) |
| Details | |
| A | |
| Mass | 0.05 M☉ |
| Luminosity | 0.2 L☉ |
| Rotation | 3.93±0.10 days |
| Rotational velocity (v sin i) | 17.4±0.3 km/s |
| Age | <1 Myr |
| B | |
| Mass | 0.015 M☉ |
| Luminosity | 0.039 L☉ |
| Age | <1 Myr |
| Other designations | |
| WDS J04236+2503A, 2MASS J04233539+2503026, Gaia DR2 149629483705467008 | |
| Database references | |
| SIMBAD | A |
| B | |
FU Tauri is a binary brown dwarf in the constellation of Taurus. Based on parallax measurements, it is about 416 light years away.
Variability
FU Tauri varies in brightness. The primary is a T Tauri variable, a type of irregular pre-main-sequence star. Its brightness has been observed to vary from a photovisual magnitude of 16.0 to fainter than 17.0. Its photographic magnitude has been measured to vary between magnitude 15.1 and below magnitude 17.6.
Characteristics
The primary and secondary, FU Tauri A and B, have spectral types of M7.25 and M9.25, which are suggestive of masses of 0.05 and 0.015 solar masses (M☉). The system is very young, only ~1 million years old. Both brown dwarfs have infrared emission that indicates the presence of circumstellar disks. The binary system has a projected separation of 5.7″, which is equivalent to a projected separation of 800 AU at the system's distance.
