AA Tauri
 Artist's impresion of AA Tauri and possible substellar companion | |
| Observation data Epoch J2000.0 Equinox J2000.0 | |
|---|---|
| Constellation | Taurus |
| Right ascension | 04h 34m 55.42s |
| Declination | +24° 28′ 53.2″ |
| Apparent magnitude (V) | 12.82 |
| Characteristics | |
| Spectral type | K7V |
| Variable type | T Tauri-type? |
| Astrometry | |
| Distance | ≈456.4 ly (≈140 pc) |
| Details | |
| Mass | 0.76[1] M☉ |
| Radius | 1.81[1] R☉ |
| Luminosity | 0.8[1] L☉ |
| Temperature | 4060[1] K |
| Age | 2.4[1] million years |
| Other designations | |
| Database references | |
| SIMBAD | data |
AA Tauri is a young star in the constellation of Taurus, located in the young Taurus-Auriga Star Forming Region, roughly at 460 light years away from the Sun.
A possible planetary system
In their paper of 2003, Grinin et al. invoke the possible presence of a substellar object to explain peculiar and periodic eclipses occurring to the young star every 8.3 days.[2] They infer a mass of 20 times that of Jupiter for the perturbing object and an orbital separation of 0.08 Astronomical Units.
In 2011, AA Tauri suddenly faded from its original brightness of V = 12.5 mag to 10.5 mag and has not changed since. Bouvier's research on this strange occurrence concluded that AA Tauri's sudden dimming was caused by an increase in dust in our line of sight to the star. They theorised that the root cause of this dimness is a warp in the galaxy's disk, located at a distance of 7.7 AU or more from the centre, that was brought into the line of sight by its elliptical motion around the central star.[3]
| Companion (in order from star) |
Mass | Semimajor axis (AU) |
Orbital period (days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | ≤20 MJ | 0.08 | 8.5 | 0 | — | — |
References
- 1 2 3 4 5 Güdel; et al. (2007). "The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)". Astronomy and Astrophysics. 468 (2): 353–377. Bibcode:2007A&A...468..353G. arXiv:astro-ph/0609160
. doi:10.1051/0004-6361:20065724. - ↑ Bouvier; et al. (2003). "Eclipses by circumstellar material in the T Tauri star AA Tau. II. Evidence for non-stationary magnetospheric accretion". Astronomy and Astrophysics. 409: 169–192. Bibcode:2003A&A...409..169B. arXiv:astro-ph/0306551 . doi:10.1051/0004-6361:20030938.
- ↑ Bouvier, J., K. Grankin, L. E. Ellerbroek, H. Bouy, and D. Barrado. (2013). "AA Tauri’s Sudden and Long-lasting Deepening: Enhanced Extinction by Its Circumstellar Disk." Astronomy & Astrophysics. 557:A77. doi:10.1051/0004-6361/201321389.