Pi1 Octantis

Pi¹ Octantis (Pi¹ Oct), Latinized π¹ Octantis, is a solitary^[11] star in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude 5.64, and is estimated to be 387 light years away. However, it is receding with a heliocentric radial velocity of 14 km/s.^[5]

For other stars with this Bayer designation, see π Octantis.

π¹ Octantis

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Octans
Right ascension	15h 01m 50.7983s[1]
Declination	−83° 13′ 39.5303″[1]
Apparent magnitude (V)	5.64±0.01[2]
Characteristics
Spectral type	G8/K0 III[3]
U−B color index	+0.74[4]
B−V color index	+0.95[4]
Astrometry
Radial velocity (Rv)	13.6±0.4[5] km/s
Proper motion (μ)	RA: +18.954 mas/yr[1] Dec.: +52.520 mas/yr[1]
Parallax (π)	8.419±0.0349 mas[1]
Distance	387 ± 2 ly (118.8 ± 0.5 pc)
Absolute magnitude (MV)	+0.24[6]
Details[7]
Mass	2.74±0.15 M☉
Radius	11.62±0.21 R☉
Luminosity	76.2±1.7 L☉
Surface gravity (log g)	2.7±0.1 cgs
Temperature	5,002±36 K
Metallicity [Fe/H]	−0.01±0.03 dex
Rotational velocity (v sin i)	<1[8] km/s
Other designations
π1 Oct, 21 G. Octantis, CPD−82°629, FK5 3987, GC 20070, HD 130650, HIP 73540, HR 5525, SAO 258713[9][10]
Database references
SIMBAD	data

Pi¹ Oct has a stellar classification of G8/K0 III^[3] — intermediate between a G8 and K0 giant star. It has 2.74 times the mass of the Sun and an effective temperature of 5,002 k,^[7] giving a yellow hue. However, an enlarged radius of 11.62 R_☉ yields a luminosity 76 times that of the Sun.^[7] Pi¹ Oct has a metallicity^[7] around solar level and spins with a projected rotational velocity lower than 1 km/s.^[8]