Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
---|---|
Constellation | Octans |
Right ascension | 18h 23m 36.44874s[1] |
Declination | −75° 02′ 39.3975″[1] |
Apparent magnitude (V) | 5.46±0.01[2] |
Characteristics | |
Spectral type | A0 V[3] |
U−B color index | +0.04[4] |
B−V color index | +0.02[4] |
Astrometry | |
Radial velocity (Rv) | 5.0±4.2[5] km/s |
Proper motion (μ) | RA: +4.621 mas/yr[1] Dec.: +19.730 mas/yr[1] |
Parallax (π) | 16.8258 ± 0.0636 mas[1] |
Distance | 193.8 ± 0.7 ly (59.4 ± 0.2 pc) |
Absolute magnitude (MV) | +1.60[6] |
Details | |
Mass | 2.86[7] M☉ |
Radius | 1.74±0.08[8] R☉ |
Luminosity | 21.1±0.1[1] L☉ |
Surface gravity (log g) | 4.48±0.14[7] cgs |
Temperature | 9,352±122[9] K |
Metallicity [Fe/H] | −0.22[10] dex |
Rotational velocity (v sin i) | 295[11] km/s |
Age | 7[7] Myr |
Other designations | |
Database references | |
SIMBAD | data |
Phi Octantis, Latinized from φ Octantis, is a solitary star[14] located in the southern circumpolar constellation Octans. It has an apparent magnitude of 5.46,[2] making it faintly visible to the naked eye if viewed under ideal conditions. The object is located relatively close at a distance of 194 light years based on Gaia DR3 parallax measurements,[1] but it is receding with a heliocentric radial velocity of approximately 5 km/s.[5] At its current distance, Phi Octantis' brightness is diminished by 0.26 magnitudes due to interstellar extinction and it has an absolute magnitude of +1.60.[6]
Phi Octantis has a stellar classification of A0 V,[3] indicating that it is an ordinary A-type main-sequence star that is generating energy via hydrogen fusion at is core. At present it has 2.7 times the mass of the Sun[7] and 1.74 times the radius of the Sun.[8] It radiates at 21.1 times the luminosity of the Sun[1] from its photosphere at an effective temperature of 9,352 K,[9] giving it a white hue when viewed in the night sky. Phi Octantis is a relatively young star with an age of only 7 million years[7] and it spins rapidly with a projected rotational velocity of 295 km/s.[11] It has a metallicity only 60% of the Sun's at [Fe/H] = −0.22.