Astronomy:81 Aquarii
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquarius |
| Right ascension | 23h 01m 23.64174s[1] |
| Declination | −07° 03′ 40.1556″[1] |
| Apparent magnitude (V) | 6.23[2] |
| Characteristics | |
| Spectral type | K5 III[3] |
| B−V color index | 1.418±0.005[2] |
| Astrometry | |
| Radial velocity (Rv) | +1.59±0.14[1] km/s |
| Proper motion (μ) | RA: −16.221±0.139[1] mas/yr Dec.: −7.911±0.087[1] mas/yr |
| Parallax (π) | 7.2372 ± 0.0691[1] mas |
| Distance | 451 ± 4 ly (138 ± 1 pc) |
| Absolute magnitude (MV) | 0.34[2] |
| Details | |
| Radius | 18.02+1.36 −2.45[1] R☉ |
| Luminosity | 102.3+1.3 −0.6[1] L☉ |
| Temperature | 4,324+329 −154[1] K |
| Other designations | |
| Database references | |
| SIMBAD | data |
81 Aquarii is a star in the constellation of Aquarius. It has an orange hue and is barely visible to the naked eye with an apparent visual magnitude of 6.23.[2] 81 Aquarii is its Flamsteed designation. The star is located at a distance of approximately 451 light years from the Sun based on parallax, and is drifting further away with a radial velocity of +1.6 km/s.[1] It is positioned near the ecliptic and thus is subject to lunar occultations.[5]
This is an aging giant star with a stellar classification of K5 III,[3] indicating it has exhausted the supply of hydrogen at its core then cooled and expanded off the main sequence. The stellar spectrum displays strong lines of cyanogen.[6] It presently has 18 times the radius of the Sun and is radiating 102 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,324 K.[1]
References
- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G. Gaia DR2 record for this source at VizieR.
- ↑ 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode: 2012AstL...38..331A.
- ↑ 3.0 3.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode: 1999MSS...C05....0H.
- ↑ "81 Aqr". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=81+Aqr.
- ↑ Evans, D. S.; Edwards, D. A. (August 1981), "Photoelectric observations of lunar occultations. XII", Astronomical Journal 86: 1277−1287, doi:10.1086/113008, Bibcode: 1981AJ.....86.1277E.
- ↑ Janes, K. A.; McClure, Robert D. (May 1971), "Strong-Cyanogen Stars: Photometry and Kinematics", Astrophysical Journal 165: 561, doi:10.1086/150921, Bibcode: 1971ApJ...165..561J.
| Stars |
| ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| |||||||||||
| |||||||||||
| |||||||||||
| Galaxies |
| ||||||||||
| |||||||||||
| |||||||||||
 |  |
