Upsilon4 Eridani

For other star systems with this Bayer designation, see Upsilon Eridani.
υ4 Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 04h 17m 53.66241s[1]
Declination −33° 47′ 54.0569″[1]
Apparent magnitude (V) 3.56[2]
Characteristics
Spectral type B8V + B9.5V[3]
U−B color index −0.36[2]
B−V color index −0.12[2]
Astrometry
Radial velocity (Rv)+17.6[4] km/s
Proper motion (μ) RA: +62.52[1] mas/yr
Dec.: −7.24[1] mas/yr
Parallax (π)18.33 ± 0.15[1] mas
Distance178 ± 1 ly
(54.6 ± 0.4 pc)
Orbit[5]
Period (P)5.010315 ± 0.000012 days
Eccentricity (e)0.0001±0.0019
Periastron epoch (T)54407.2201 ± 0.0012 JD
Semi-amplitude (K1)
(primary)		62.68±0.17 km/s
Semi-amplitude (K2)
(secondary)		64.70±0.15 km/s
Details
υ4 Eri A
Mass3.85[6] M☉
Surface gravity (log g)4.23±0.14[6] cgs
Temperature12,930±440[6] K
Rotational velocity (v sin i)19[6] km/s
Age146[6] Myr
υ4 Eri B
Temperature12,250[5] K
Other designations
υ4 Eri, 41 Eridani, CD −34° 1614, HD 27376, HIP 20042, HR 1347, SAO 194902.[7]

Upsilon4 Eridani is a binary star system in the constellation Eridanus. It is visible to the naked eye with an apparent visual magnitude of 3.56.[2] Based upon parallax measurements, the pair are located around 54.6 parsecs (178 ly) from the Sun.[1]

This is a double-lined spectroscopic binary star system,[8] which means that the Doppler-shifted spectral lines of both components can be distinguished. The system is composed of two B-type main-sequence stars: one has a stellar classification of B8V and the other B9.5V.[3] Both stars show HgMn peculiarities in their spectrum.[5] It is possible that a nearby K-type star is also related.[3]

References

  1. 1 2 3 4 5 6 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
  2. 1 2 3 4 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV data, SIMBAD, Bibcode:1986EgUBV........0M.
  3. 1 2 3 Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878Freely accessible, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
  4. ↑ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, eds., "The Revision of the General Catalogue of Radial Velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, Bibcode:1967IAUS...30...57E.
  5. 1 2 3 Hubrig, S.; et al. (November 2012), "Magnetic fields of HgMn stars", Astronomy & Astrophysics, 547: 24, arXiv:1208.2910Freely accessible, Bibcode:2012A&A...547A..90H, doi:10.1051/0004-6361/201219778, A90.
  6. 1 2 3 4 5 David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154Freely accessible, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  7. ↑ "ups04 Eri -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2016-10-13.
  8. ↑ Chini, R.; et al. (2012), "A spectroscopic survey on the multiplicity of high-mass stars", Monthly Notices of the Royal Astronomical Society, 424 (3): 1925, arXiv:1205.5238Freely accessible, Bibcode:2012MNRAS.424.1925C, doi:10.1111/j.1365-2966.2012.21317.x.
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