77 Aquarii
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 22h 54m 45.47121s[1] |
| Declination | –16° 16′ 19.0392″[1] |
| Apparent magnitude (V) | 5.55[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.089[2] |
| B−V color index | +1.104[2] |
| Astrometry | |
| Radial velocity (Rv) | –36.3[4] km/s |
| Proper motion (μ) | RA: –219.73[1] mas/yr Dec.: –87.78[1] mas/yr |
| Parallax (π) | 24.28 ± 0.56 mas[1] |
| Distance | 134 ± 3 ly (41.2 ± 0.9 pc) |
| Details | |
| Radius | 6[5] R☉ |
| Luminosity | 13.5[5] L☉ |
| Surface gravity (log g) | 2.8[5] cgs |
| Temperature | 4,581[5] K |
| Metallicity [Fe/H] | +0.03[5] dex |
| Rotational velocity (v sin i) | 3.9[5] km/s |
| Other designations | |
77 Aquarii (abbreviated 77 Aqr) is a star in the equatorial constellation of Aquarius. 77 Aquarii is its Flamsteed designation. It has an apparent visual magnitude of 5.55[2] and is around 134 light-years (41 parsecs) from Earth. This is a giant star with a stellar classification of K1 III.[3] It has six times the radius of the Sun and shines with 13.5 times the Sun's luminosity. The outer atmosphere has an effective temperature of 4,581 K,[5] giving it the orange-hued glow of a K-type star.[7]
References
- ^ a b c d e van Leeuwen, F. (November 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 Jennens, P. A.; Helfer, H. L. (September 1975), "A new photometric metal abundance and luminosity calibration for field G and K giants.", Monthly Notices of the Royal Astronomical Society, 172: 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
{{citation}}: CS1 maint: unflagged free DOI (link) - ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1988mcts.book.....H.
- ^ Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington, D.C., Bibcode:1953GCRV..C......0W.
- ^ a b c d e f g Massarotti, Alessandro; et al. (January 2008), "Rotational and radial velocities for a sample of 761 HIPPARCOS giants and the role of binarity", The Astronomical Journal, 135 (1): 209–231, Bibcode:2008AJ....135..209M, doi:10.1088/0004-6256/135/1/209.
- ^ "77 Aqr -- Variable Star", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-15.
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-01-16
