UX Tauri
Binary star system in the constellation Taurus
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UX Tauri, abbreviated as UX Tau, is a binary star system approximately 450 light-years away in the constellation of Taurus (the Bull). It is notable for the fact that, despite its recent (in stellar terms) creation, the Spitzer Space Telescope discovered that its protoplanetary disk contains a gap. The dust, which normally accumulates in an expanding ring starting right next to the star at such a young age, is either very thin or nonexistent at a range of 0.2 to 56 AU from the star. Typically, this means that the early ancestors of planets may be forming from the disk, though the star only ignited about 1 million years ago.[10] In contrast, Earth was formed approximately 4.54 billion years ago, placing its formation about sixty million years after the Sun's ignition around 4.6 billion years ago.
An artist's conception of a circumstellar disk around UX Tauri A, along with several hypothetical protoplanets | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Taurus[1] |
| Right ascension | 04h 30m 03.99626s[2] |
| Declination | +18° 13′ 49.4355″[2] |
| Apparent magnitude (V) | 10.5 - 13.9[3] |
| Characteristics | |
| Spectral type | K2Ve + M1Ve[4] |
| Variable type | T Tau[5] |
| Astrometry | |
| Radial velocity (Rv) | 22.90[6] km/s |
| Proper motion (μ) | RA: 17.18[2] mas/yr Dec.: -21.91[2] mas/yr |
| Parallax (π) | -3.70[2]±5.73 mas |
| Distance | 450 ly (138 pc) |
| Details[7] | |
| UX Tauri A | |
| Mass | 1.25 M☉ |
| Luminosity | 1.3 L☉ |
| Surface gravity (log g) | 4.0 cgs |
| Temperature | 4,460 K |
| Age | 3 Myr |
| UX Tauri B | |
| Mass | 0.4 M☉ |
| Luminosity | 0.5 L☉ |
| Surface gravity (log g) | 3.5 cgs |
| Temperature | 3,500 K |
| Age | 1 Myr |
| Other designations | |
| UX Tau, HD 285846, HIP 20990, WDS J04301+1814AB, CCDM J04301+1814AB, 1RXS J043004.5+181342[8] | |
| Database references | |
| SIMBAD | data |
