Pi2 Pegasi

For other stars with this Bayer designation see π Pegasi

π² Pegasi, Latinized as Pi² Pegasi, is a single^[8] star in the northern constellation Pegasus. It is yellow-white in hue and visible to the naked eye as a faint point of light with an apparent visual magnitude of +4.28.^[2] The distance to this object is approximately 263 light years based on parallax,^[1] and it is drifting further away with a radial velocity of +5 km/s.^[2] This star is an outlying member of the Ursa Major Moving Group.^[9]

π¹ Pegasi (right) and π² Pegasi (left) in optical light

π² Pegasi

Location of π2 Pegasi (circled)
Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Pegasus
Right ascension	22h 09m 59.24371s[1]
Declination	+33° 10′ 41.5976″ [1]
Apparent magnitude (V)	+4.28[2]
Characteristics
Spectral type	F5 III[3]
B−V color index	0.471±0.012[2]
Astrometry
Radial velocity (Rv)	+5.1±0.9[2] km/s
Proper motion (μ)	RA: −12.87±0.12[1] mas/yr Dec.: −18.95±0.16[1] mas/yr
Parallax (π)	12.40±0.17 mas[1]
Distance	263 ± 4 ly (81 ± 1 pc)
Absolute magnitude (MV)	0.21[4]
Details
Mass	2.48[5] M☉
Radius	8.5±0.8[6] R☉
Luminosity	102.9±2.6[6] L☉
Temperature	6,300+298 −263[6] K
Rotational velocity (v sin i)	139.7[4] km/s
Age	530[5] Myr
Other designations
π2 Peg, 29 Pegasi, BD+32°4352, FK5 835, HD 210459, HIP 109410, HR 8454, SAO 72077[7]
Database references
SIMBAD	data

This object has a stellar classification of F5 III,^[3] matching an aging giant star that has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. At present it has 8.5^[6] times the radius of the Sun. The star is 530^[5] million years old with 2.48^[5] times the Sun's mass. It shows a high rotation rate considering its evolutionary status, with a projected rotational velocity of 140 km/s.^[4] The star has been noted as a possible variable shell star.^[10] Pi² Pegasi is radiating 103 times the Sun's luminosity from its swollen photosphere at an effective temperature of 6,300 K.^[6]