AA Tauri

AA Tauri

A visual band light curve for AA Tauri, adapted from Bouvier et al. (2013).[1] The main plot shows the long term variation, and the inset plot shows the periodic variation after the dramatic dimming in 2011.
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Taurus
Right ascension 04h 34m 55.42019s[2]
Declination +24° 28′ 53.0336″[2]
Apparent magnitude (V) 12.2 to 16.1[3]
Characteristics
Spectral type K7Ve[4]
Variable type T Tauri-type?[4]
Astrometry
Radial velocity (Rv)16.98±0.04[5] km/s
Proper motion (μ) RA: +5.323 mas/yr[2]
Dec.: −20.680 mas/yr[2]
Parallax (π)7.4255 ± 0.0868 mas[2]
Distance439 ± 5 ly
(135 ± 2 pc)
Details
Mass0.76[6] M☉
Radius1.81[6] R☉
Luminosity0.8[6] L☉
Temperature4,060[6] K
Rotational velocity (v sin i)12.8±1.1[5] km/s
Age2.4[6] Myr
Other designations
AA Tau, GCRV 55202, XEST 25-026, AN 196.1930, GSC 01833-00851, 2MASS J04345542+2428531, CSI+24-04319, MHA 259-17, 2E 0431.8+2422, IRAS 04318+2422, UBV 4396, 2E 1098, IRAS F04318+2422, XEST 25-OM-003[7]
Database references
SIMBADdata

AA Tauri is a young variable star in the equatorial constellation of Taurus, located in the Taurus-Auriga star-forming region. It is too faint to view with the naked eye, having an apparent visual magnitude that varies from 12.2 down to 16.1.[3] The star is located approximately 439 light-years (135 parsecs) away from the Sun based on parallax, and is drifting further away with a radial velocity of +17 km/s.[5]

The stellar classification for this object is K7Ve,[4] matching a K-type main-sequence star that displays emission features. It is an eruptive variable of the T Tauri type[3] with an estimated age of 2.4 million years. The object has 76% of the mass of the Sun, 181% of the Sun's radius,[6] and is spinning with a projected rotational velocity of 13 km/s.[5] AA Tauri is radiating 80% of the luminosity of the Sun at an effective temperature of 4,060 K.[6]

  1. ^ Cite error: The named reference bouvier2013 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference GaiaDR3 was invoked but never defined (see the help page).
  3. ^ a b c Samus, N. N.; et al. (2017). "General Catalogue of Variable Stars". Astronomy Reports. 5.1. 61 (1): 80–88. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085. S2CID 125853869.
  4. ^ a b c Herbig, G. H. (1977). "Radial velocities and spectral types of T Tauri stars". Astrophysical Journal. 214: 747–758. Bibcode:1977ApJ...214..747H. doi:10.1086/155304.
  5. ^ a b c d Nguyen, Duy Cuong; et al. (February 2012). "Close Companions to Young Stars. I. A Large Spectroscopic Survey in Chamaeleon I and Taurus-Auriga". The Astrophysical Journal. 745 (2): 25. arXiv:1112.0002. Bibcode:2012ApJ...745..119N. doi:10.1088/0004-637X/745/2/119. S2CID 119265730. 119.
  6. ^ a b c d e f g Güdel; et al. (2007). "The XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST)". Astronomy and Astrophysics. 468 (2): 353–377. arXiv:astro-ph/0609160. Bibcode:2007A&A...468..353G. doi:10.1051/0004-6361:20065724. S2CID 8846597.
  7. ^ "AA Tau". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2019-08-10.