Upsilon2 Centauri

For other stars with this Bayer designation, see υ Centauri.
Upsilon2 Centauri
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Centaurus
Right ascension 14h 01m 43.49909 s[1]
Declination −45° 36′ 12.2767″[1]
Apparent magnitude (V) +4.33[2]
Characteristics
Spectral type F7 II/III[3]
U−B color index +0.26[2]
B−V color index +0.61[2]
Variable type None[4]
Astrometry
Radial velocity (Rv)−7.8±7.4[5] km/s
Proper motion (μ) RA: +8.64±1.09[1] mas/yr
Dec.: −16.25±0.88[1] mas/yr
Parallax (π)2.57 ± 1.05 mas[1]
Distanceapprox. 1,300 ly
(approx. 400 pc)
Absolute magnitude (MV)−3.51[4]
Orbit[6]
Period (P)207.357 d
Eccentricity (e)0.55
Periastron epoch (T)2423880.5 JD
Argument of periastron (ω)
(secondary)		88°
Semi-amplitude (K1)
(primary)		12.7 km/s
Details
Mass6.86±0.39[7] M☉
Luminosity (bolometric)3,919[7] L☉
Surface gravity (log g)2.00[8] cgs
Temperature6,495[7] K
Rotational velocity (v sin i)0.0[8] km/s
Age45.9±4.0[9] Myr
Other designations
υ2 Cen, CD−44° 9040, GC 18939, HD 122223, HIP 68523, HR 5260, SAO 224621[10]
Database references
SIMBADdata

Upsilon2 Centauri (υ2 Centauri) is a binary star[6] system in the southern constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude of +4.33.[2] Based upon an annual parallax shift of just 2.57 mas as seen from Earth,[1] this star is located roughly 1,300 light years from the Sun. Relative to its neighbors, the system has a peculiar velocity of 39.2+8.8
−15.2 km/s and it may form a runaway star system.[9]

This is a single-lined spectroscopic binary star system with an orbital period of 207.357 days and an eccentricity of 0.55.[6] The primary component has the spectrum of an evolved F-type giant/bright giant hybrid with a stellar classification of F7 II/III.[3] It is around 46[9] million years old with 6.9 times the mass of the Sun. The star is radiating 3,919 times the Sun's luminosity from its photosphere at an effective temperature of 6,495 K.[7]

  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 c d Cite error: The named reference fernie1983 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Eggen1985 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference Pourbaix was invoked but never defined (see the help page).
  7. ^ a b c d Cite error: The named reference Hohle2010 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference Mallik2003 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).