Pi Eridani

Pi Eridani, Latinized from π Eridani, is a star in the constellation Eridanus. It has an apparent visual magnitude of 4.40,^[2] which is bright enough to be seen on a dark, clear night. Based upon parallax measurements, it is located roughly 480 light years from the Sun.

π Eridani

Observation data Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation	Eridanus
Right ascension	03h 46m 08.53581s[1]
Declination	−12° 06′ 05.7282″[1]
Apparent magnitude (V)	4.40[2] (4.38 - 4.44[3])
Characteristics
Evolutionary stage	asymptotic giant branch[4]
Spectral type	M1 III[5]
U−B color index	+1.96[2]
B−V color index	+1.61[2]
Variable type	Lb?[3]
Astrometry
Radial velocity (Rv)	45.2±0.1[6] km/s
Proper motion (μ)	RA: +55.98[1] mas/yr Dec.: +59.28[1] mas/yr
Parallax (π)	6.78±0.53 mas[1]
Distance	480 ± 40 ly (150 ± 10 pc)
Absolute magnitude (MV)	−1.40[7]
Details
Radius	77[8] R☉
Luminosity	1,123[9] L☉
Temperature	3,841[9] K
Other designations
π Eridani, π Eri, 26 Eridani, BD−12°707, HD 23614, HIP 17593, HR 1162, SAO 149158[10]
Database references
SIMBAD	data

This is an evolved red giant star with a stellar classification of M1 III,^[5] and is currently on the asymptotic giant branch.^[4] It is a slow irregular variable type LB that can increase in magnitude up to 4.38.^[3][11] The measured angular diameter of this star is 4.8±0.5 mas.^[12] At the estimated distance of Pi Eridani, this yields a physical size of about 77 times the radius of the Sun.^[8] It shines with 1,123^[9] times the luminosity of the Sun from an outer atmosphere at an effective temperature of 3,841 K.^[9]