Astronomy:69 Aquilae
| Observation data Equinox J2000.0]] (ICRS) | |
|---|---|
| Constellation | Aquila |
| Right ascension | 20h 29m 38.99995s[1] |
| Declination | −02° 53′ 07.9176″[1] |
| Apparent magnitude (V) | 4.91[2] |
| Characteristics | |
| Evolutionary stage | giant[3] |
| Spectral type | K1/2 III[4] |
| B−V color index | 1.162[3] |
| Astrometry | |
| Radial velocity (Rv) | −22.51±0.16[1] km/s |
| Proper motion (μ) | RA: +70.355[1] mas/yr Dec.: –21.523[1] mas/yr |
| Parallax (π) | 16.2388 ± 0.2271[1] mas |
| Distance | 201 ± 3 ly (61.6 ± 0.9 pc) |
| Absolute magnitude (MV) | 0.97[2] |
| Details[3] | |
| Mass | 1.54[5] M☉ |
| Radius | 11 R☉ |
| Luminosity | 45.7 L☉ |
| Surface gravity (log g) | 2.5 cgs |
| Temperature | 4,529±5 K |
| Metallicity [Fe/H] | 0.03 dex |
| Rotational velocity (v sin i) | 4.0 km/s |
| Age | 3.44[5] Gyr |
| Other designations | |
| Database references | |
| SIMBAD | data |
69 Aquilae, abbreviated 69 Aql, is a star in the equatorial constellation of Aquila. 69 Aquilae is its Flamsteed designation. It is visible to the naked eye with an apparent visual magnitude of 4.91.[2] Based upon an annual parallax shift of 16.2 mas,[1] it is located 201 light years away. The star is moving closer to the Earth with a heliocentric radial velocity of −22.5 km/s.[1]
The stellar classification of 69 Aquilae is K1/2 III,[4] which means this is an evolved giant star. It belongs to a sub-category called the red clump, indicating that it is on the horizontal branch and is generating energy through helium fusion at its core.[7] The star is about 3.4 billion years old with 1.54[5] times the mass of the Sun and has expanded to 11 times the Sun's radius.[3] It is radiating 45.7 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,529 K.[3]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 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.
- ↑ 2.0 2.1 2.2 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 3.2 3.3 3.4 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, doi:10.1088/0004-6256/135/1/209, Bibcode: 2008AJ....135..209M.
- ↑ 4.0 4.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode: 1999MSS...C05....0H.
- ↑ 5.0 5.1 5.2 Luck, R. Earle (2015), "Abundances in the Local Region. I. G and K Giants", Astronomical Journal 150 (3): 23, doi:10.1088/0004-6256/150/3/88, Bibcode: 2015AJ....150...88L.
- ↑ "69 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=69+Aql.
- ↑ Alves, David R. (August 2000), "K-Band Calibration of the Red Clump Luminosity", The Astrophysical Journal 539 (2): 732–741, doi:10.1086/309278, Bibcode: 2000ApJ...539..732A.
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