15 Aquilae
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aquila |
| Right ascension | 19h 04m 57.67233s[1] |
| Declination | –04° 01′ 53.1059″[1] |
| Apparent magnitude (V) | 5.41[2] |
| Characteristics | |
| Spectral type | K1 III[3] |
| U−B color index | +1.01[2] |
| B−V color index | +1.12[2] |
| Astrometry | |
| Radial velocity (Rv) | –23.17 ± 0.61[4] km/s |
| Proper motion (μ) | RA: +21.90[1] mas/yr Dec.: -26.05[1] mas/yr |
| Parallax (π) | 11.27 ± 0.36 mas[1] |
| Distance | 289 ± 9 ly (89 ± 3 pc) |
| Absolute magnitude (MV) | 0.414[5] |
| Details | |
| Radius | 14[4] R☉ |
| Luminosity | 83[4] L☉ |
| Surface gravity (log g) | 2.65[3] cgs |
| Temperature | 4,560[3] K |
| Metallicity [Fe/H] | –0.25[3] dex |
| Rotational velocity (v sin i) | 3.4[4] km/s |
| Age | 4.09 ± 2.07[5] Gyr |
| Other designations | |
15 Aquilae is the Flamsteed designation for a star in the equatorial constellation of Aquila. It has the Bayer designation h Aquilae. The apparent visual magnitude of this star is is 5.41,[2] meaning that it is faintly visible to the naked eye. It has a nearby optical companion, HD 177442.[7] The distance to 15 Aquilae can be estimated from its annual parallax shift of 11.27 mas,[1] yielding a range of approximately 289 light-years (89 parsecs) from Earth with a 9 light-year margin of error.
With a stellar classification of K1 III,[3] the spectrum of 15 Aquilae matches a giant star with an estimated age of roughly four billion years.[5] At this stage of its evolution, the outer atmosphere of the star has expanded to 14[4] times the radius of the Sun. It is radiating 83[4] times the Sun's luminosity into space at an effective temperature of 4,560 K.[3] This heat gives it the orange-hued glow of a K-type star.[8]
This star is most likely a member of the thin disk population of the Milky Way. It is orbiting through the galaxy with an eccentricity of 0.06, which carries it as close as 24.30 kilolight-years (7.45 kpc) to the Galactic Core, and as far away as 27.60 kilolight-years (8.46 kpc). The orbital inclination carries it no more than 196 ly (60 pc) from the galactic plane.[5]
References
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357.
{{citation}}: Unknown parameter|month=ignored (help) - ^ a b c d Cousins, A. W. J. (1964), "Photometric Data for Stars in the Equatorial Zone (Seventh List)", Monthly Notes of the Astronomical Society of Southern Africa, 23: 175, Bibcode:1964MNSSA..23..175C.
- ^ a b c d e f Frasca, A.; et al. (2009), "REM near-IR and optical photometric monitoring of pre-main sequence stars in Orion. Rotation periods and starspot parameters", Astronomy and Astrophysics, 508 (3): 1313–1330, Bibcode:2009A&A...508.1313F, doi:10.1051/0004-6361/200913327.
{{citation}}: Unknown parameter|month=ignored (help) - ^ a b c d e f Massarotti, Alessandro; et al. (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.
{{citation}}: Unknown parameter|month=ignored (help) - ^ a b c d Soubiran, C.; et al. (2008), "Vertical distribution of Galactic disk stars. IV. AMR and AVR from clump giants", Astronomy and Astrophysics, 480 (1): 91–101, Bibcode:2008A&A...480...91S, doi:10.1051/0004-6361:20078788.
- ^ "h Aql -- Star in double system", SIMBAD Astronomical Object Database, Centre de Données astronomiques de Strasbourg, retrieved 2012-07-22.
- ^ Eggleton, P. P.; Tokovinin, A. A. (2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society. 389 (2): 869–879. Bibcode:2008MNRAS.389..869E. doi:10.1111/j.1365-2966.2008.13596.x.
{{cite journal}}: Unknown parameter|month=ignored (help)CS1 maint: postscript (link) CS1 maint: unflagged free DOI (link) - ^ "The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, retrieved 2012-07-21.
