Pi2 Gruis

For other stars with this Bayer designation, see π Gruis.
Pi2 Gruis
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Grus
Right ascension 22h 23m 07.98704s[1]
Declination −45° 55′ 42.5582″[1]
Apparent magnitude (V) 5.622[2] (5.71 + 11.3)[3]
Characteristics
Spectral type F3 III-IV[4][3] or F0 V[5]
U−B color index +0.016[2]
B−V color index +0.365[2]
Astrometry
Radial velocity (Rv)3.0[6] km/s
Proper motion (μ) RA: +233.166[1] mas/yr
Dec.: −58.205[1] mas/yr
Parallax (π)25.1061 ± 0.1256 mas[1]
Distance129.9 ± 0.6 ly
(39.8 ± 0.2 pc)
Absolute magnitude (MV)2.62[7]
Details
π2 Gru A
Mass1.37[8] M☉
Radius1.93±0.07[1] R☉
Luminosity7.15±0.04[1] L☉
Surface gravity (log g)4.20[8] cgs
Temperature6788+138
−101[1] K
Metallicity [Fe/H]−0.06[6] dex
Age758[8] Myr
Other designations
π2 Gru, CD−46°14295, FK5 3786, HD 212132, HIP 110506, HR 8524, SAO 231111, WDS J22231-4556[9]
Database references
SIMBADdata

π2 Gruis, Latinised as Pi2 Gruis, is a binary star[3] system in the southern constellation of Grus. It is faintly visible to the naked eye as a yellow-white hued star with an apparent visual magnitude of 5.622.[2] Based upon an annual parallax shift of 25.1 mas as seen from the Earth,[1] the system is located 130 light years from the Sun.

The primary, component A, is an F-type star of uncertain luminosity class. Malaroda (1975) gave it a stellar classification of F3 III-IV,[4] which would indicate an evolving subgiant/giant star hybrid spectrum, whereas Houk (1978) listed it as class F0 V,[5] suggesting that it is an F-type main sequence star. It has been considered to be a chemically peculiar star,[10] but this is now considered doubtful.[11] It is 758[8] million years old with 1.4[8] times the mass of the Sun. The star is 1.9[1] times the Sun's radius and is radiating 7[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,788 K.[1]

The companion is a magnitude 11.3 star at an angular separation of 4.6 arc seconds.[3] Gaia Data Release 2 has measured a separate annual parallax for it of 25.3266±0.0871 mas, almost identical to the primary star, and indicates that it is a red dwarf.[12]

  1. ^ a b c d e f g h i j k l Cite error: The named reference GaiaDR2 was invoked but never defined (see the help page).
  2. ^ a b c d Cite error: The named reference Cousins1983 was invoked but never defined (see the help page).
  3. ^ a b c d Cite error: The named reference Eggleton2008 was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference Malaroda1975 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Houk1978 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Casagrande2011 was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  8. ^ a b c d e Cite error: The named reference David2015 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 devaucouleurs was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference renson was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference dr2b was invoked but never defined (see the help page).