Pi2 Columbae

π² Columbae, Latinized as Pi² Columbae, is a binary star^[9] system in the southern constellation of Columba, near the southern constellation border with Pictor. It is white-hued and dimly visible to the naked eye with a combined apparent visual magnitude of 5.50.^[2] Based upon an annual parallax shift of 12.8 mas as seen from Earth,^[1] this system is located about 254 light years from the Sun. They are receding with a heliocentric radial velocity of +31 km/s.^[4]

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

Pi² Columbae

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Columba
Right ascension	06h 07m 52.86009s[1]
Declination	−42° 09′ 14.5488″[1]
Apparent magnitude (V)	5.50[2]
Characteristics
Spectral type	A0 V + A[3]
B−V color index	+0.00[2]
Astrometry
Radial velocity (Rv)	+31.0±3.7[4] km/s
Proper motion (μ)	RA: −10.612[1] mas/yr Dec.: −16.928[1] mas/yr
Parallax (π)	12.8296±0.1132 mas[1]
Distance	254 ± 2 ly (77.9 ± 0.7 pc)
Absolute magnitude (MV)	+1.17[5]
Details[6]
Mass	2.64 M☉
Luminosity	31[7] L☉
Surface gravity (log g)	4.38±0.14 cgs
Temperature	11,223±382 K
Rotational velocity (v sin i)	274 km/s
Age	98 Myr
Other designations
π2 Col, CD−42° 2351, HD 42303, HIP 29064, HR 2181, SAO 217730[8]
Database references
SIMBAD	data

The pair have an angular separation of 0.1^[3] arc seconds with the primary being an A-type main-sequence star of spectral class A0 V,^[3] while the secondary component is a similar A-type star.^[9] The primary is 98 million years old with 2.6 times the mass of the Sun and is spinning rapidly with a projected rotational velocity of 274 km/s.^[6] It is radiating 31^[7] times the luminosity of the Sun from its photosphere at an effective temperature of 11,223 K. The system is a source of X-ray emission with a luminosity of 184.3×10²⁰ W, which is considered unusual since A-type stars are not expected to display magnetic activity.^[3]