Upsilon1 Eridani

Upsilon1 Eridani (υ1 Eri) is a single star in the constellation Eridanus. It has an apparent visual magnitude is 4.51,[2] which is bright enough to be faintly visible to the naked eye on a clear, dark night. The distance to this star, as determined using the parallax method,[1] is around 127 light years.

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

an

υ1 Eridani
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Eridanus
Right ascension 04h 33m 30.55236s[1]
Declination −29° 45′ 59.3725″[1]
Apparent magnitude (V) 4.51[2]
Characteristics
Spectral type K0 III-IV[3]
U−B color index +0.70[2]
B−V color index +0.98[2]
Astrometry
Radial velocity (Rv)+20.89±0.69[4] km/s
Proper motion (μ) RA: −114.78[1] mas/yr
Dec.: −271.79[1] mas/yr
Parallax (π)25.67 ± 0.24[1] mas
Distance127 ± 1 ly
(39.0 ± 0.4 pc)
Absolute magnitude (MV)1.60[4]
Details
Mass1.54[4] M☉
Radius7.3[5] R☉
Luminosity24[4] L☉
Surface gravity (log g)3.09[4] cgs
Temperature4,941[4] K
Metallicity [Fe/H]−0.16±0.08[4] dex
Rotational velocity (v sin i)2.15[6] km/s
Other designations
υ1 Eridani, υ1 Eri, 50 Eridani, CD−30° 1883, HD 29085, HIP 21248, HR 1453, SAO 169570.[7]
Database references
SIMBADdata

This is an evolved red clump[8] giant star with a stellar classification of K0III-IV.[3] The measured angular diameter, after correction for limb darkening, is 1.74±0.02 mas.[9] At an estimated distance of this star, this yields a physical size of about 7.3 times the radius of the Sun.[5] It has 154%[4] of the Sun's mass and radiates 24 times the solar luminosity from its outer atmosphere at an effective temperature of 4,941 K.[4]

References
  1. 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. Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.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. Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
  4. Luck, R. Earle; Heiter, Ulrike (June 2007), "Giants in the Local Region", The Astronomical Journal, 133 (6): 2464–2486, Bibcode:2007AJ....133.2464L, doi:10.1086/513194.
  5. Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1. The radius (R*) is given by:
  6. Hekker, S.; Meléndez, J. (2007). "Precise radial velocities of giant stars. III. Spectroscopic stellar parameters". Astronomy and Astrophysics. 475 (3): 1003. arXiv:0709.1145. Bibcode:2007A&A...475.1003H. doi:10.1051/0004-6361:20078233. S2CID 10436552.
  7. "* ups01 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2016-10-13.
  8. Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal, 539 (2): 732–741, arXiv:astro-ph/0003329, Bibcode:2000ApJ...539..732A, doi:10.1086/309278, S2CID 16673121.
  9. Richichi, A.; et al. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.