2 Ceti

2 Ceti
Observation data
Epoch J2000      Equinox J2000
Constellation Cetus
Right ascension 00h 03m 44.38784s[1]
Declination −17° 20′ 09.5719″[1]
Apparent magnitude (V) 4.483[2]
Characteristics
Spectral type B9 IVn[3]
U−B color index −0.12[4]
B−V color index −0.047±0.003[5]
Astrometry
Radial velocity (Rv)+8.0±4.6[6] km/s
Proper motion (μ) RA: +25.17[1] mas/yr
Dec.: −9.16[1] mas/yr
Parallax (π)11.98 ± 0.26 mas[1]
Distance272 ± 6 ly
(83 ± 2 pc)
Absolute magnitude (MV)−0.06[5]
Details
Mass2.68±0.11[7] M☉
Radius2.75[7] R☉
Luminosity119+6
−5[8] L☉
Surface gravity (log g)3.99±0.09[7] cgs
Temperature11,419±388[9] K
Metallicity [Fe/H]+0.00±0.24[3] dex
Rotational velocity (v sin i)116[8] or 237[10] km/s
Age217[9] Myr
Other designations
2 Cet, BD−18° 6417, FK5 905, HD 225132, HIP 301, HR 9098, SAO 147059[11]
Database references
SIMBADdata

2 Ceti is a single[12] star in the equatorial constellation of Cetus, near the border with Aquarius. It is visible to the naked eye with an apparent visual magnitude of 4.483.[2] The distance to 2 Ceti can be estimated from its annual parallax shift of 12.0 mas,[1] which yields a value of around 272 light years. It appears to be moving further from the Earth with a heliocentric radial velocity of about +8 km/s.[6]

The stellar classification for this star is B9 IVn,[3] matching a B-type subgiant star with "nebulous" absorption lines due to rapid rotation.[13] Estimates of the rotation rate range from 116[8] to 237[10] km/s, and this high rate of spin is giving the star an equatorial bulge that is 12% larger than the polar radius.[13] 2 Ceti is about 217[9] million years old with 2.7[7] times the mass of the Sun and 2.75[7] times the Sun's radius. It is radiating 119[8] times the Sun's luminosity from its photosphere at an effective temperature of 11,419 K.[9] An infrared excess has been detected around this star by the Akari satellite at a wavelength of 18μm, suggesting there is an orbiting debris disk.[14]

  1. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference TYC2 was invoked but never defined (see the help page).
  3. ^ a b c Cite error: The named reference Wu was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference UBV was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference RV was invoked but never defined (see the help page).
  7. ^ a b c d e Cite error: The named reference AllendePrieto was invoked but never defined (see the help page).
  8. ^ a b c d Cite error: The named reference zorec2012 was invoked but never defined (see the help page).
  9. ^ a b c d Cite error: The named reference David2015 was invoked but never defined (see the help page).
  10. ^ a b Cite error: The named reference Royer2007 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference chini2012 was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference vanBelle2012 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Ishihara2017 was invoked but never defined (see the help page).