Phi2 Orionis

For other stars with this Bayer designation, see Phi Orionis.
φ2 Orionis
φ2 (circled) in the constellation Orion
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Orion
Right ascension 05h 36m 54.389s[1]
Declination +09° 17′ 26.417″[1]
Apparent magnitude (V) 4.081[2]
Characteristics
Evolutionary stage Yellow giant
Spectral type G8 III-IV[3]
U−B color index +0.618[2]
B−V color index +0.966[2]
Astrometry
Radial velocity (Rv)99.03±0.18[1] km/s
Proper motion (μ) RA: +98.301 mas/yr[1]
Dec.: −305.022 mas/yr[1]
Parallax (π)28.6722 ± 0.1859 mas[1]
Distance113.8 ± 0.7 ly
(34.9 ± 0.2 pc)[1]
Absolute magnitude (MV)+1.33±0.07[4]
Details[5]
Mass1.07±0.04 M☉
Radius8.22±0.07[6] R☉
Luminosity29.8±0.04[6] L☉
Surface gravity (log g)3.00±0.02 cgs
Temperature4,703±11[6] K
Metallicity [Fe/H]−0.56±0.02 dex
Rotational velocity (v sin i)1.91±0.53 km/s
Age6.91±1.04 Gyr
Other designations
φ2 Ori, 40 Orionis, BD+09° 898, HD 37160, HIP 26366, HR 1907, SAO 112958[7]
Database references
SIMBADdata
Yellow φ2 Orionis with nebulosity east of φ1 Orionis and south-east of λ Orionis

Phi2 Orionis is a star in the constellation Orion, where it forms a small triangle on the celestial sphere with the nearby Meissa and Phi1 Orionis.[8] This star is visible to the naked eye with an apparent visual magnitude of 4.081.[2] Based upon an annual parallax shift of 28.67 mas,[6] it is located around 114 light-years from the Sun.

This is an evolved G-type star of stellar classification G8 III-IV,[3] which means that it is in an evolutionary stage between a subgiant (IV) and a giant star (III). It is estimated to be 6.9 billion years old, has 1.07 times the mass of the Sun,[5] but has expanded to 8 times the Sun's radius. The star shines with 30 times the solar luminosity from its outer atmosphere at an effective temperature of 4,700 K.[6]

  1. ^ a b c d e f Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  2. ^ a b c d Cite error: The named reference Cousins1984 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference Frasca2009 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference Charbonnel1998 was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference jofre2015 was invoked but never defined (see the help page).
  6. ^ a b c d e Cite error: The named reference npoi was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Kaler2012 was invoked but never defined (see the help page).