TW Hydrae

TW Hydrae

Inner region of TW Hydrae protoplanetary disc
Credit: S. Andrews, B. Saxton, ALMA (see description)
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Hydra
Right ascension 11h 01m 51.9054s[1]
Declination −34° 42′ 17.0316″[1]>
Apparent magnitude (V) 11.27 ± 0.09[2]
Characteristics
Evolutionary stage Pre-main-sequence
Spectral type K6[2]
U−B color index -0.33[3]
B−V color index 0.67[2]
J−H color index 0.659[2]
J−K color index 0.92[2]
Variable type T Tauri
Astrometry
Radial velocity (Rv)13.40 ± 0.8[2] km/s
Proper motion (μ) RA: −68.389 ± 0.054[1] mas/yr
Dec.: −14.016 ± 0.059[1] mas/yr
Parallax (π)16.6428 ± 0.0416 mas[1]
Distance196.0 ± 0.5 ly
(60.1 ± 0.2 pc)
Details
Mass0.8[4] M
Radius1.11[5] R
Luminosity (bolometric)0.28[note 1] L
Temperature4,000[5] K
Age8[5] Myr
Other designations
TWA 1, TW Hya, CD−34° 7151, HIP 53911
Database references
SIMBADdata

TW Hydrae is a T Tauri star approximately 196 light-years away[1] in the constellation of Hydra (the Sea Serpent). TW Hydrae is about 80% of the mass of the Sun, but is only about 5-10 million years old. The star appears to be accreting from a protoplanetary disk of dust and gas, oriented face-on to Earth, which has been resolved in images from the ALMA observatory. TW Hydrae is accompanied by about twenty other low-mass stars with similar ages and spatial motions, comprising the "TW Hydrae association" or TWA, one of the closest regions of recent "fossil" star-formation to the Sun.

  1. ^ a b c d e f Cite error: The named reference Gaia DR2 was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  3. ^ Cite error: The named reference Mermilliod1991+2006 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Chunhua2013 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Rheeetal2007 was invoked but never defined (see the help page).


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