Upsilon4 Eridani

For other star systems with this Bayer designation, see Upsilon Eridani.
Upsilon4 Eridani
Location of Upsilon4 in Eridanus (circled)
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 mas[1]
Distance178 ± 1 ly
(54.6 ± 0.4 pc)
Absolute magnitude (MV)−0.20[5]
Orbit[6]
Period (P)5.0103250±0.0000008 d
Semi-major axis (a)1.902±0.006 mas
Eccentricity (e)0
Inclination (i)146.2±0.1°
Periastron epoch (T)2454407.7214 ± 0.002 JD
Semi-amplitude (K1)
(primary)		62.68±0.17[7] km/s
Semi-amplitude (K2)
(secondary)		64.70±0.15[7] km/s
Details[6]
υ4 Eri A
Mass3.17±0.07 M☉
Radius2.32±0.18 R☉
Luminosity100.6±4.3 L☉
Surface gravity (log g)4.21±0.07 cgs
Temperature12,930±440[8] K
Rotational velocity (v sin i)19[8] km/s
Age146[8] Myr
υ4 Eri B
Mass3.07±0.07 M☉
Radius2.32±0.18 R☉
Luminosity87.4±3.3 L☉
Surface gravity (log g)4.21±0.07 cgs
Temperature12,250 K
Other designations
υ4 Eri, 41 Eridani, CD−34° 1614, HD 27376, HIP 20042, HR 1347, SAO 194902.[9]
Database references
SIMBADdata

Upsilon4 Eridani is a close 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,[10] which means that the Doppler-shifted spectral lines of both components can be distinguished. The pair have a circular orbit with a period of five days. 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,[7] and their properties are nearly identical.[6] The spin rate of the two stars is synchronized to their orbital period.[6] It is possible that a nearby K-type star is also related.[3]

References

  1. ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  2. ^ a b c d 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. ^ a b c 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:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
  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, vol. 30, University of Toronto: International Astronomical Union, p. 57, Bibcode:1967IAUS...30...57E.
  5. ^ Hubrig, S.; et al. (June 2001), "Search for low-mass PMS companions around X-ray selected late B stars", Astronomy and Astrophysics, 372: 152–164, arXiv:astro-ph/0103201, Bibcode:2001A&A...372..152H, doi:10.1051/0004-6361:20010452, S2CID 17507782.
  6. ^ a b c d Hummel, Christian A.; Schöller, Markus; Duvert, Gilles; Le Bouquin, Jean-Baptiste; Hubrig, Swetlana (2016), "The orbit of the mercury-manganese binary 41 Eridani", in Malbet, Fabien; Creech-Eakman, Michelle J.; Tuthill, Peter G. (eds.), Optical and Infrared Interferometry and Imaging V, Proceedings of SPIE, vol. 9907, pp. 99070Q, arXiv:1703.07668, Bibcode:2016SPIE.9907E..0QH, doi:10.1117/12.2231859, S2CID 125160002
  7. ^ a b c Hubrig, S.; et al. (November 2012), "Magnetic fields of HgMn stars", Astronomy & Astrophysics, 547: 24, arXiv:1208.2910, Bibcode:2012A&A...547A..90H, doi:10.1051/0004-6361/201219778, S2CID 85520917, A90.
  8. ^ a b c 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:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146, S2CID 33401607.
  9. ^ "* ups04 Eri -- Spectroscopic binary". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-13.{{cite web}}: CS1 maint: postscript (link)
  10. ^ 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:1205.5238, Bibcode:2012MNRAS.424.1925C, doi:10.1111/j.1365-2966.2012.21317.x, S2CID 119120749.