Eta Crateris

Eta Crateris, Latinized from η Crateris, is a solitary[9] star in the southern constellation of Crater. It marks the lip of the tilted bowl on the left side in the constellation. Eta Crateris lies in the sky NE of Zeta Crateris and NNW of 31 Crateris, the three stars forming an almost perfect right triangle with Eta at the right angle and 31 and Zeta the ends of the hypotenuse. Eta Crateris also lies to the right (west) of the bright star Gamma Corvi.

η Crateris
Location of η Crateris (circled)
Observation data
Epoch J2000.0      Equinox J2000.0 (ICRS)
Constellation Crater
Right ascension  11h 56m 00.95323s[1]
Declination −17° 09′ 02.9781″[1]
Apparent magnitude (V) 5.17[2]
Characteristics
Spectral type A0 V[3]
U−B color index −0.06[2]
B−V color index −0.03[2]
Astrometry
Radial velocity (Rv)+15.0±4.2[4] km/s
Proper motion (μ) RA: −49.74[1] mas/yr
Dec.: −7.58[1] mas/yr
Parallax (π)12.97 ± 0.23[1] mas
Distance251 ± 4 ly
(77 ± 1 pc)
Absolute magnitude (MV)+1.00[5]
Details
Radius2.7[6] R☉
Luminosity48.5[7] L☉
Temperature9,687[7] K
Rotational velocity (v sin i)65[3] km/s
Age350[5] Myr
Other designations
η Crt, 30 Crateris, BD−16°3358, FK5 1309, HD 103632, HIP 58188, HR 4567, SAO 156988[8]
Database references
SIMBADdata

This star is faintly visible to the naked eye with an apparent visual magnitude of 5.17.[2] With an annual parallax shift of 12.97 mas as seen from Earth,[1] it is located around 280 light years from the Sun. At that distance, the visual magnitude is diminished by an extinction factor of 0.08 due to interstellar dust.[5] The star is receding from the Sun with a radial velocity of +15 km/s.[4]

Eta Crateris is an ordinary A-type main sequence star with a stellar classification of A0 V.[3] It is about 2.7[6] times the radius of the Sun and radiates 48.5 times the solar luminosity from its outer atmosphere at an effective temperature of 9,687 K.[7] It 350[5] million years old and is spinning with a projected rotational velocity of 65 km/s.[3]

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.
  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 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.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. Royer, F.; et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics, 463 (2): 671–682, arXiv:astro-ph/0610785, Bibcode:2007A&A...463..671R, doi:10.1051/0004-6361:20065224.
  4. de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, A61.
  5. Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv:1606.09028, Bibcode:2012AstL...38..694G, doi:10.1134/S1063773712110035.
  6. Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics (3rd ed.), 367: 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451.
  7. McDonald, I.; et al. (2012), "Fundamental Parameters and Infrared Excesses of Hipparcos Stars", Monthly Notices of the Royal Astronomical Society, 427 (1): 343–57, arXiv:1208.2037, Bibcode:2012MNRAS.427..343M, doi:10.1111/j.1365-2966.2012.21873.x.
  8. "eta Crt". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-02-26.
  9. 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.
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