Astronomy:Eta Crateris
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| Observation data 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 |
| Distance | 251 ± 4 ly (77 ± 1 pc) |
| Absolute magnitude (MV) | +1.00[5] |
| Details | |
| Mass | 2.55±0.02[6] M☉ |
| Radius | 2.47[7] R☉ |
| Luminosity | 57±2[6] L☉ |
| Temperature | 9,930±90[6] K |
| Rotational velocity (v sin i) | 65[3] km/s |
| Age | 350[5] Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
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.
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 has 2.55 times the mass[6] and 2.47 times the radius of the Sun.[7] It radiates 57 times the solar luminosity from its outer atmosphere at an effective temperature of 9,930 K.[6] It is 350 million years old[5] and is spinning with a projected rotational velocity of 65 km/s.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 2.0 2.1 2.2 2.3 Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data (SIMBAD), Bibcode: 1986EgUBV........0M.
- ↑ 3.0 3.1 3.2 3.3 Royer, F. et al. (February 2007), "Rotational velocities of A-type stars. III. Velocity distributions", Astronomy and Astrophysics 463 (2): 671–682, doi:10.1051/0004-6361:20065224, Bibcode: 2007A&A...463..671R.
- ↑ 4.0 4.1 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, doi:10.1051/0004-6361/201219219, A61, Bibcode: 2012A&A...546A..61D.
- ↑ 5.0 5.1 5.2 5.3 Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters 38 (11): 694–706, doi:10.1134/S1063773712110035, Bibcode: 2012AstL...38..694G.
- ↑ 6.0 6.1 6.2 6.3 6.4 Zorec, J.; Royer, F. (2012-01-01), "Rotational velocities of A-type stars. IV. Evolution of rotational velocities", Astronomy and Astrophysics 537: A120, doi:10.1051/0004-6361/201117691, ISSN 0004-6361, Bibcode: 2012A&A...537A.120Z.
- ↑ 7.0 7.1 McDonald, I.; Zijlstra, A. A.; Watson, R. A. (2017-10-01), "Fundamental parameters and infrared excesses of Tycho-Gaia stars", Monthly Notices of the Royal Astronomical Society 471: 770–791, doi:10.1093/mnras/stx1433, ISSN 0035-8711, Bibcode: 2017MNRAS.471..770M. Eta Crateris' database entry at VizieR.
- ↑ "eta Crt". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=eta+Crt.
- ↑ 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
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