1 Centauri

"i centauri" redirects here. Not to be confused with j centauri, l Centauri, or ι Centauri.
1 Centauri
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Centaurus
Right ascension 13h 45m 41.24482s[1]
Declination −33° 02′ 37.3997″[1]
Apparent magnitude (V) +4.23[2]
Characteristics
Spectral type F2 V[3]
U−B color index +0.00[4]
B−V color index +0.38[4]
Astrometry
Radial velocity (Rv)−21.5±0.6[5] km/s
Proper motion (μ) RA: −462.49±0.18[1] mas/yr
Dec.: −146.49±0.16[1] mas/yr
Parallax (π)51.54 ± 0.19 mas[1]
Distance63.3 ± 0.2 ly
(19.40 ± 0.07 pc)
Absolute magnitude (MV)+2.81[6]
Orbit[7]
Period (P)9.94480±0.00441 d
Eccentricity (e)0.247±0.105
Periastron epoch (T)2,422,737.382 ± 3.35 JD
Argument of periastron (ω)
(secondary)		137.7±25.4°
Semi-amplitude (K1)
(primary)		6.00±0.75 km/s
Details
Mass1.35[6] M☉
Luminosity (bolometric)5.857[8] L☉
Surface gravity (log g)4.25±0.14[9] cgs
Temperature6,898±235[9] K
Metallicity [Fe/H]−0.09[8] dex
Rotation2.42±0.22[8]
Rotational velocity (v sin i)86[6] km/s
Age1.193[9] Gyr
Other designations
i Centauri, 1 Centauri, CD−32°9603, FK5 506, GC 18593, GJ 525.1, HD 119756, HIP 67153, HR 5168, SAO 204812[10]
Database references
SIMBADdata

1 Centauri, or i Centauri,[10] is a yellow-white-hued binary star[7] system in the southern constellation Centaurus. It can be seen with the naked eye, having an apparent visual magnitude of +4.23.[2] Based upon an annual parallax shift of 51.54 mas as seen from Earth's orbit, it is located 51.5 light-years from the Sun. The system is moving closer to the Sun with a radial velocity of −21.5 km/s.[5]

Spectrographic images taken at the Cape Observatory between 1921 and 1923 showed this star has a variable radial velocity, which indicated this is a single-lined spectroscopic binary star system. The pair have an orbital period of 9.94 days and an eccentricity of about 0.2.[7]

The primary component has received a number of different stellar classifications. For example, Jaschek et al. (1964) lists F0V, F2III, F4III and F4IV, thus ranging in evolutionary state from an ordinary F-type main-sequence star to a giant star.[11] More recently, Houk (1982) listed a class of F3 V,[12] matching an ordinary main-sequence star that is generating energy through hydrogen fusion at its core. The NStars project gives it a classification of F2 V.[3]

  1. ^ a b c d e Cite error: The named reference van Leeuwen2007 was invoked but never defined (see the help page).
  2. ^ a b Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Gray2006 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference hr was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference deBruijne2012 was invoked but never defined (see the help page).
  6. ^ a b c Cite error: The named reference aaa361_614 was invoked but never defined (see the help page).
  7. ^ a b c Cite error: The named reference Jones1928 was invoked but never defined (see the help page).
  8. ^ a b c Cite error: The named reference Montesinos2016 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference David2015 was invoked but never defined (see the help page).
  10. ^ a b "1 Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-02-09.
  11. ^ Cite error: The named reference Hauck1979 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference houk1979 was invoked but never defined (see the help page).