Theta Crateris

Theta Crateris
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Crater
Right ascension 11h 36m 40.91335s[1]
Declination −09° 48′ 08.0912″[1]
Apparent magnitude (V) 4.70[2]
Characteristics
Spectral type B9.5 Vn[3]
U−B color index −0.18[2]
B−V color index −0.08[2]
Astrometry
Radial velocity (Rv)+2.09±3.78[4] km/s
Proper motion (μ) RA: −59.38[1] mas/yr
Dec.: +2.55[1] mas/yr
Parallax (π)11.63 ± 0.23 mas[1]
Distance280 ± 6 ly
(86 ± 2 pc)
Absolute magnitude (MV)+0.63[5]
Details
Mass2.79[6] M☉
Radius3.1[7] R☉
Luminosity107[8] L☉
Surface gravity (log g)3.96±0.14[6] cgs
Temperature11,524±392[6] K
Rotational velocity (v sin i)212[3] km/s
Age117[6] Myr
Other designations
θ Crt, 21 Crateris, BD−08°3202, FK5 1299, HD 100889, HIP 56633, HR 4468, SAO 138296.[9]
Database references
SIMBADdata

Theta Crateris (θ Crateris) is a solitary[10] star in the southern constellation of Crater. It is a photometric-standard star[11] that is faintly visible to the naked eye with an apparent visual magnitude of 4.70.[2] With an annual parallax shift of 11.63 mas as seen from Earth, it is located around 280 light years from the Sun. At that distance, the visual magnitude of the star is diminished by an extinction factor of 0.07 because of interstellar dust.[5]

This is a B-type main sequence star with a stellar classification of B9.5 Vn,[3] where the 'n' suffix indicates "nebulous" absorption lines due to rapid rotation. It is spinning with a projected rotational velocity of 212 km/s,[3] giving the star an oblate shape with an equatorial bulge that is an estimated 7% larger than the polar radius.[12] The star has 2.79[6] times the mass of the Sun and around 3.1[7] times the Sun's radius. With an age of about 117 million years,[6] it is radiating 107[8] times the solar luminosity from its outer atmosphere at an effective temperature of 11,524 K.[6]

  1. ^ a b c d e Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Nicolet1978 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Becker2015 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Gontcharov2012 was invoked but never defined (see the help page).
  6. ^ a b c d e f g Cite error: The named reference David2015 was invoked but never defined (see the help page).
  7. ^ a b Cite error: The named reference PasinettiFracassini2001 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  9. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Stritzinger2005 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference belle2012 was invoked but never defined (see the help page).