24 Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 18m 50.94332s[1] |
| Declination | 00° 20′ 20.4817″[1] |
| Apparent magnitude (V) | 6.423[2] |
| Characteristics | |
| Spectral type | K0 IIIa[3] |
| U−B color index | +0.770[2] |
| B−V color index | +1.050[2] |
| Astrometry | |
| Radial velocity (Rv) | -28.5[4] km/s |
| Proper motion (μ) | RA: +15.96[1] mas/yr Dec.: +8.77[1] mas/yr |
| Parallax (π) | 7.87 ± 0.49[1] mas |
| Distance | 410 ± 30 ly (127 ± 8 pc) |
| Absolute magnitude (MV) | +0.64[3] |
| Details | |
| Mass | 2.2[3] M☉ |
| Luminosity | 63[3] L☉ |
| Surface gravity (log g) | 2.48[5] cgs |
| Temperature | 4,810[5] K |
| Metallicity [Fe/H] | –0.19 ± 0.06[5] dex |
| Age | 0.5[3] Gyr |
| Other designations | |
24 Aquilae (abbreviated 24 Aql) is a star in the equatorial constellation of Aquila. 24 Aquilae is its Flamsteed designation. It is at a distance of around 410 light-years (130 parsecs)[1] from Earth and has an apparent visual magnitude of 6.4.[2] According to the Bortle Dark-Sky Scale, this star is just visible to the naked eye in dark rural skies.
This is a so-called mild barium star, as identified by the mild presence of an absorption line of singly-ionized barium atoms at a wavelength of 455.4 nm. Such stars display an atmospheric overabundance of carbon and the heavy elements produced by the s-process, which was most likely transferred into the atmosphere by a wide binary stellar companion. However, in the case of 24 Aquilae, the abundances of heavy elements are near normal.[3]
At an estimated age of a half billion years,[3] 24 Aquilae is a giant star with a stellar classification of K0 IIIa.[3] It has more than double the mass of the Sun and shines with 63[3] times the Sun's luminosity. It is radiating this energy into space from its outer atmosphere at an effective temperature of 4,810 K.[5] This heat is what gives it the cool orange hue characteristic of a K-type star.[7]
References
- 1 2 3 4 5 6 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.
- 1 2 3 4 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.
- 1 2 3 4 5 6 7 8 9 Smiljanic, R.; Porto de Mello, G. F.; da Silva, L. (June 2007), "Abundance analysis of barium and mild barium stars", Astronomy and Astrophysics 468 (2): 679–693, arXiv:astro-ph/0702421, Bibcode:2007A&A...468..679S, doi:10.1051/0004-6361:20065867.
- ↑ Wilson, Ralph Elmer (1953), General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, Bibcode:1953QB901.W495......
- 1 2 3 4 Soubiran, C.; Le Campion, J.-F.; Cayrel de Strobel, G.; Caillo, A. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, arXiv:1004.1069, Bibcode:2010A&A...515A.111S, doi:10.1051/0004-6361/201014247.
- ↑ "24 Aql -- Star in double system", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), retrieved 2012-07-25.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16
External links
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