Tau8 Eridani

For other star systems with this Bayer designation, see Tau Eridani.
τ8 Eridani

A light curve for Tau8 Eridani, plotted from TESS data[1]
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 03h 53m 42.70302s[2]
Declination −24° 36′ 44.0309″[2]
Apparent magnitude (V) 4.63 - 4.65[3]
Characteristics
Spectral type B6 V[4]
U−B color index −0.48[5]
B−V color index −0.13[5]
Variable type SPB[3]
Astrometry
Radial velocity (Rv)+23[6] km/s
Proper motion (μ) RA: +31.28[2] mas/yr
Dec.: −7.49[2] mas/yr
Parallax (π)8.65 ± 0.30 mas[2]
Distance380 ± 10 ly
(116 ± 4 pc)
Absolute magnitude (MV)−0.67[7]
Orbit[8]
Period (P)459±4 d
Eccentricity (e)0.18±0.02
Periastron epoch (T)2450954±7 JD
Argument of periastron (ω)
(secondary)		106±5°
Semi-amplitude (K1)
(primary)		21.7±0.4 km/s
Details
τ8 Eri A
Mass5.0±0.1[9] M☉
Luminosity256[10] L☉
Surface gravity (log g)4.00[11] cgs
Temperature11,858[10] K
Rotational velocity (v sin i)30[4] km/s
Age32.8±9.9[9] Myr
Other designations
τ8 Eridani, τ8 Eri, 33 Eridani, CD−24°1945, HD 24587, HIP 18216, HR 1213, SAO 168925.[12]
Database references
SIMBADdata

Tau8 Eridani, Latinized from τ8 Eridani, is a binary star system in the constellation Eridanus. It is visible to the naked eye with a combined apparent visual magnitude of 4.65.[5] The distance to this system can be estimated via the parallax method, yielding a value of around 380 light years.[2]

This is a single-lined[13] spectroscopic binary star system with an orbital period of about 459 days and an eccentricity of 0.18.[8] The primary component is a B-type main sequence star with a stellar classification of B6 V.[4] It is a slowly pulsating B-type star that undergoes radial-velocity variation with a frequency of 1.1569 times per day.[13] The star has about five[9] times the mass of the Sun and shines with 256 times the Sun's luminosity.[10] The outer atmosphere has an effective temperature of 11,858[10] K and may possess a longitudinal magnetic field with a strength of −140±71 G.[14]

  1. ^ Cite error: The named reference MAST was invoked but never defined (see the help page).
  2. ^ a b c d e f Cite error: The named reference vanLeeuwen2007 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference magnitude was invoked but never defined (see the help page).
  4. ^ a b c Cite error: The named reference Abt2002 was invoked but never defined (see the help page).
  5. ^ a b c Cite error: The named reference Johnson1966 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference rgcrv was invoked but never defined (see the help page).
  7. ^ Cite error: The named reference Anderson2012 was invoked but never defined (see the help page).
  8. ^ a b Cite error: The named reference decat2000 was invoked but never defined (see the help page).
  9. ^ a b c Cite error: The named reference Tetzlaff2011 was invoked but never defined (see the help page).
  10. ^ a b c d Cite error: The named reference Mcdonald2012 was invoked but never defined (see the help page).
  11. ^ Cite error: The named reference Lefever2010 was invoked but never defined (see the help page).
  12. ^ Cite error: The named reference SIMBAD was invoked but never defined (see the help page).
  13. ^ a b Cite error: The named reference Szewczuk2015 was invoked but never defined (see the help page).
  14. ^ Cite error: The named reference Banulo2012 was invoked but never defined (see the help page).