77 Aquarii - Misplaced Pages

Star in the constellation of Aquarius

77 Aquarii
Observation data Epoch J2000 Equinox J2000
Constellation	Aquarius
Right ascension	22 54 45.47009
Declination	–16° 16′ 19.0505″
Apparent magnitude (V)	5.55
Characteristics
Evolutionary stage	giant
Spectral type	K1 III
U−B color index	+1.089
B−V color index	+1.104
Variable type	suspected
Astrometry

Radial velocity (R_v)	−34.59±0.16 km/s
Proper motion (μ)	RA: –222.505 mas/yr Dec.: –88.355 mas/yr
Parallax (π)	24.1777 ± 0.1211 mas
Distance	134.9 ± 0.7 ly (41.4 ± 0.2 pc)
Absolute magnitude (M_V)	2.46

Details

Mass	1.14 `M`_☉
Radius	5.79+0.22 −0.21 `R`_☉
Luminosity	13.347±0.085 `L`_☉
Surface gravity (log g)	2.8 cgs
Temperature	4,583+86 −83 K
Metallicity	+0.03 dex
Rotational velocity (v sin i)	3.9 km/s
Age	7.61 Gyr

Other designations
70 Aqr, NSV 14358, BD−17°6619, HD 216640, HIP 113148, HR 8711, SAO 165376
Database references
SIMBAD	data

77 Aquarii is a single star located 135 light years away from the Sun in the equatorial constellation of Aquarius. 77 Aquarii is its Flamsteed designation. It is visible to the naked eye as a dim star with a baseline apparent visual magnitude of 5.55. The star is moving closer to the Earth with a heliocentric radial velocity of −35 km/s.

At the estimated age of 7.61 billion years old, this is an aging giant star with a stellar classification of K1 III. It is a suspected variable star that ranges in brightness from a maximum of magnitude 5.53 down to 5.60. 77 Aquarii has 1.14 times the mass of the Sun and, after exhausting the hydrogen at its core, has expanded to six times the Sun's radius. It is radiating 13.3 times the Sun's luminosity from its photosphere at an effective temperature of 4,581 K, giving it the orange-hued glow of a K-type star.

References

^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
^ 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 (3): 667–679, Bibcode:1975MNRAS.172..667J, doi:10.1093/mnras/172.3.667.
^ 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.
^ Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
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, S2CID 119257644.
^ Wittenmyer, Robert A.; Liu, Fan; Wang, Liang; Casagrande, Luca; Johnson, John Asher; Tinney, C. G. (July 2016), "The Pan-Pacific Planet Search. V. Fundamental Parameters for 164 Evolved Stars", The Astronomical Journal, 152 (1): 15, arXiv:1605.00323, Bibcode:2016AJ....152...19W, doi:10.3847/0004-6256/152/1/19, S2CID 55991800, 19.
^ 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". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-15.
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, S2CID 14878976.
"The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on March 18, 2012, retrieved 2012-01-16

External links

Image 77 Aquarii

Constellation of Aquarius

Stars

Bayer	α (Sadalmelik) β (Sadalsuud) γ (Sadachbia) δ (Skat) ε (Albali) ζ η θ (Ancha) ι κ (Situla) λ (Hydor) μ ν ξ (Bunda) ο π ρ σ τ τ υ φ χ ψ (91) ψ ψ ω ω A A b b b c c c d e f g g h i i i k α PsA C
Flamsteed	1 4 5 7 8 9 10 11 12 14 15 16 17 18 19 20 21 24 26 28 29 30 32 35 36 37 39 40 41 42 44 45 47 49 50 51 54 56 58 60 61 64 65 67 70 72 74 75 77 78 81 82 84 85 87 94 96 97 100
Variable	R U AE DV EP EW EZ FO HK IL HU IZ LL LP
HR	8017 8056 8121 8263 8363 8453 8500 8507 8581 8612 8629 8645 8716 8783 8836 8856 8879 8924 9014
HD	206610 (Bosona) 210277 212771 (Lionrock) 215152 219617 220466 220689 222093 222582
Other	2MASS J21392676+0220226 BD−22 5866 Gliese 849 K2-21 K2-28 K2-58 K2-72 K2-138 LS IV-14 116 Sneden's Star TRAPPIST-1 WASP-6 (Márohu) WASP-47 WASP-69 WASP-75

Exoplanets	ψ Aquarii b Gliese 849 b Gliese 876 b c d e HD 206610 b HD 210277 b HD 212771 b (Victoriapeak) HD 221416 b HD 222582 b K2-66b K2-72b c d e K2-138b TRAPPIST-1b c d e f g h WASP-6b

Star clusters	Messier 2 Messier 72 Messier 73

Nebulae	Helix Nebula Saturn Nebula

Galaxies

NGC	6975 7001 7010 7047 7051 7065 7069 7077 7081 7184 7222 7252 7257 7301 7302 7393 7492 7585 7592 7600 7606 7723 7727 7759
Other	Aquarius Dwarf ESO 603-G21 Lyman-alpha blob 1 PGC 1228197 PHL 293B SMM J2135-0102 WISE J224607.57−052635.0 J2345-0449

Galaxy clusters	Abell 2597 RXC J2211.7-0350 XMMXCS 2215-1738

Astronomical events	SN 2213-1745