Eta Gruis
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Grus |
| Right ascension | 22h 45m 37.88204s[1] |
| Declination | −53° 30′ 00.4353″[1] |
| Apparent magnitude (V) | 4.85[2] |
| Characteristics | |
| Spectral type | K2 III CNIV[3] |
| U−B color index | +1.17[2] |
| B−V color index | +1.18[2] |
| Astrometry | |
| Radial velocity (Rv) | +27.8±2.8[4] km/s |
| Proper motion (μ) | RA: +30.59[1] mas/yr Dec.: +17.37[1] mas/yr |
| Parallax (π) | 7.86 ± 0.23 mas[1] |
| Distance | 410 ± 10 ly (127 ± 4 pc) |
| Absolute magnitude (MV) | −0.68[5] |
| Details | |
| Luminosity | 275[5] L☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
Eta Gruis, Latinized from η Gruis, is a solitary,[7] orange-hued star in the southern constellation of Grus. It is visible to the naked eye with an apparent visual magnitude of 4.85.[2] Based upon an annual parallax shift of 7.86 mas as seen from the Earth,[1] the system is located about 410 light years from the Sun. This is an evolved K-type giant star with a stellar classification of K2 III CNIV,[3] indicating this is an intermediate CN star. It is a periodic microvariable with an amplitude of 0.0055 magnitude and a frequency of 0.36118 cycles per day.[8]
References
- ^ 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.
- ^ a b c d Johnson, H. L.; et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory, 4 (99), Bibcode:1966CoLPL...4...99J.
- ^ a b Houk, Nancy; Cowley, A. P. (1979), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 1, Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
- ^ Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
- ^ a b Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters, 38 (5): 331, arXiv:1108.4971, Bibcode:2012AstL...38..331A, doi:10.1134/S1063773712050015.
- ^ "eta Gru". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-06-28.
{{cite web}}: CS1 maint: postscript (link) - ^ 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.
- ^ Koen, Chris; Eyer, Laurent (2002), "New periodic variables from the Hipparcos epoch photometry", Monthly Notices of the Royal Astronomical Society, 331: 45, arXiv:astro-ph/0112194, Bibcode:2002MNRAS.331...45K, doi:10.1046/j.1365-8711.2002.05150.x.
