P Eridani

p Eridani

Observation data Epoch J2000.0      Equinox J2000.0
Constellation	Eridanus
A
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	5.76
B
Right ascension	Template:RA
Declination	Template:DEC
Apparent magnitude (V)	5.87
Characteristics
Spectral type	K2V + K2V
U−B Template:Engvar	+0.59 / +0.53
B−V Template:Engvar	+0.90 / +0.87
Astrometry
A
Radial velocity (Rv)	km/s
Proper motion (μ)	RA: +262.615 mas/yr Dec.: +14.961 mas/yr
Parallax (π)	122.1088±0.0365 mas
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	6.25
B
Radial velocity (Rv)	km/s
Proper motion (μ)	RA: +309.230 mas/yr Dec.: +10.815 mas/yr
Parallax (π)	122.0035±0.0319 mas
Distance	Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc)
Absolute magnitude (MV)	6.27
Details
p Eri A
Mass	Template:Solar mass
Radius	Template:Solar radius
Luminosity	Template:Solar luminosity
Surface gravity (log g)	cgs
Temperature	K
Metallicity [Fe/H]	–0.24 dex
Rotation	30 days
Age	4.94 Gyr
p Eri B
Mass	Template:Solar mass
Radius	Template:Solar radius
Luminosity	Template:Solar luminosity
Surface gravity (log g)	cgs
Temperature	K
Metallicity [Fe/H]	–0.19 dex
Rotation	39 days
Age	1.96 Gyr
Other designations
Template:Odlist
p Eri A: Template:Odlist
p Eri B: Template:Odlist
Database references
SIMBAD	data
	p Eri A
	p Eri B

p Eridani is a binary star system in the constellation of Eridanus (the River) whose distance from the Sun is 26.7 light-years based upon parallax. It was found to be a double star in December 1825 by James Dunlop in Australia at his home at Paramatta, now spelt Parramatta. It is visible to the naked eye as a dim, orange-hued star. The system is moving further from the Earth with a heliocentric radial velocity of about .

This system consists of a pair of near identical K-type main-sequence stars with stellar classifications of K2V. Component A has visual magnitude 5.87, while component B is magnitude 5.76. They orbit each other with a period of 394 years, an eccentricity of 0.576, and a semimajor axis of .

Naming

The name "p Eridani", according to Nature, p. 589 (19 April 1883) has been "occasionally miscalled 6 Eridani, which would imply that it was one of Flamsteed's stars. Flamsteed, it is true has a star which he calls 6 Eridani. The designated letter 'p' was attached to a star by Lacaille in the catalogue at the end of his Coelum Australe Stelliferum. The number '6' is merely borrowed from Bode."

The use of Bode numbers was commonly used in the early 19th century, but this antiquated system has now fallen into disuse for more than a century.

See also

• List of star systems within 25–30 light-years
• List of nearest K-type stars
• Gliese 65
• Gliese 67