Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Octans |
Right ascension | 22h 17m 50.5954s[1] |
Declination | −77° 30′ 41.599″[1] |
Apparent magnitude (V) | 5.47±0.01[2] |
Characteristics | |
Evolutionary stage | main sequence[1] |
Spectral type | F0IIp[3] (F4V:kA5)[4] |
U−B color index | +0.12[5] |
B−V color index | +0.31[5] |
Astrometry | |
Radial velocity (Rv) | 17.0±1.6[6] km/s |
Proper motion (μ) | RA: −37.392 mas/yr[1] Dec.: +13.788 mas/yr[1] |
Parallax (π) | 25.7575 ± 0.0505 mas[1] |
Distance | 126.6 ± 0.2 ly (38.82 ± 0.08 pc) |
Absolute magnitude (MV) | +2.56[7] |
Details | |
Mass | 1.49±0.07[8] M☉ |
Radius | 1.74±0.04[8] R☉ |
Luminosity | 7.82[7] L☉ |
Surface gravity (log g) | 4.13±0.05[8] cgs |
Temperature | 7,244[8] K |
Metallicity [Fe/H] | −0.04[9] dex |
Age | 1.41[9] Gyr |
Other designations | |
Database references | |
SIMBAD | data |
Psi Octantis, Latinized from ψ Octantis, is a solitary[12] star in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.47,[2] allowing it to be seen with the naked eye under ideal conditions. The star is relatively close at a distance of 126 light years[1] but is receding with a heliocentric radial velocity of 17 km/s.[6]
Psi Octantis has a spectral classification of F0IIp, suggesting that it is a bright giant but with peculiarities. Other assessments give a luminosity class of III (giant),[13] III-IV (intermediate between giant and subgiant),[14] or V: (approximately main sequence).[4] One paper gives a spectral class of F4V:kA5, indicating that it is a probable F-type main-sequence star with the calcium K-lines of an A5 star, including sharp absorption lines of metals.[4] Analysis of its evolutionary stage show it to be a somewhat evolved main sequence star.[1]
It has 149% the mass of the Sun and 1.74 times the radius of the Sun.[8] It shines at 7.82 times the luminosity of the Sun[7] from its photosphere at an effective temperature of 7,244 K,[8] giving it a yellowish white glow. Psi Octantis has an iron abundance 91% that of the Sun and is estimated to be 1.41 billion years old.[9]