P Eridani

Not to be confused with ρ Eridani.
p Eridani
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Eridanus
A
Right ascension 01h 39m 47.813s[1]
Declination −56° 11′ 35.94″[1]
Apparent magnitude (V) 5.76[2]
B
Right ascension 01h 39m 47.565s[3]
Declination −56° 11′ 47.21″[3]
Apparent magnitude (V) 5.87[2]
Characteristics
Spectral type K2V + K2V[4]
U−B color index +0.59 / +0.53[2]
B−V color index +0.90 / +0.87[2]
Astrometry
A
Radial velocity (Rv)+21.74±0.12[1] km/s
Proper motion (μ) RA: 262.615[1] mas/yr
Dec.: 14.961[1] mas/yr
Parallax (π)122.1088 ± 0.0365 mas[1]
Distance26.710 ± 0.008 ly
(8.189 ± 0.002 pc)
Absolute magnitude (MV)6.25[5]
B
Radial velocity (Rv)+20.15±0.12[3] km/s
Proper motion (μ) RA: 309.230[3] mas/yr
Dec.: 10.815[3] mas/yr
Parallax (π)122.0035 ± 0.0319 mas[3]
Distance26.733 ± 0.007 ly
(8.196 ± 0.002 pc)
Absolute magnitude (MV)6.27[5]
Orbit[6]
Period (P)475.2 yr
Semi-major axis (a)7.826″
Eccentricity (e)0.5344
Inclination (i)140.5°
Longitude of the node (Ω)13.7°
Periastron epoch (T)1811.90
Argument of periastron (ω)
(secondary)		18.6°
Details
p Eri A
Mass0.78[7] M☉
Radius0.75[1] R☉
Luminosity0.339[8] L☉
Surface gravity (log g)4.63[7] cgs
Temperature5,077[7] K
Metallicity [Fe/H]–0.24[7] dex
Rotation30[9] days
Age4.94[7] Gyr
p Eri B
Mass0.77[7] M☉
Radius0.77[3] R☉
Luminosity0.311[3] L☉
Surface gravity (log g)4.65[7] cgs
Temperature5,117[7] K
Metallicity [Fe/H]–0.19[7] dex
Rotation39[9] days
Age1.96[7] Gyr
Other designations
DUN 5, p Eri, CD−56°328, GJ 66, HIP 7751, SAO 232490, WDS 01398-5612
p Eri A: HD 10360, HR 486, LTT 903
p Eri B: HD 10361, HR 487, LTT 902
Database references
SIMBADdata
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 +20 km/s.

This system consists of a pair of near identical K-type main-sequence stars with stellar classifications of K2V.[4] Component A has visual magnitude 5.87, while component B is magnitude 5.76.[2] They orbit each other with a period of 475.2 years, an eccentricity of 0.53, and a semimajor axis of 7.8″.[6]

  1. ^ a b c d e f g Cite error: The named reference dr3a was invoked but never defined (see the help page).
  2. ^ a b c d e Cite error: The named reference hr was invoked but never defined (see the help page).
  3. ^ a b c d e f g h Cite error: The named reference dr3b was invoked but never defined (see the help page).
  4. ^ a b Cite error: The named reference gray was invoked but never defined (see the help page).
  5. ^ a b Cite error: The named reference Holmberg2009 was invoked but never defined (see the help page).
  6. ^ a b Cite error: The named reference Hartkopf2006 was invoked but never defined (see the help page).
  7. ^ a b c d e f g h i j Cite error: The named reference ag2018 was invoked but never defined (see the help page).
  8. ^ Cite error: The named reference Hinkel2017 was invoked but never defined (see the help page).
  9. ^ a b Cite error: The named reference mnras284_803 was invoked but never defined (see the help page).