8 Aquilae

8 Aquilae is a star in the equatorial constellation of Aquila,[9] located 266 light years away from the Sun.[1] 8 Aquilae is the Flamsteed designation. It can be viewed with the naked eye in good seeing conditions, appearing as a dim, yellow-white hued star with an apparent visual magnitude of 6.08.[2] The star is moving further from the Earth with a heliocentric radial velocity of +12 km/s.[2]

8 Aquilae
Observation data
Epoch J2000      Equinox J2000
Constellation Aquila
Right ascension 18h 51m 22.15810s[1]
Declination –03° 19′ 04.2832″[1]
Apparent magnitude (V) 6.08[2]
Characteristics
Spectral type F0 IV[3] or F2 III[4]
U−B color index +0.06[5]
B−V color index +0.299±0.007[6]
Variable type δ Sct[4]
Astrometry
Radial velocity (Rv)+11.8[2] km/s
Proper motion (μ) RA: +2.128[1] mas/yr
Dec.: –21.533[1] mas/yr
Parallax (π)12.2584 ± 0.0631 mas
Distance266 ± 1 ly
(81.6 ± 0.4 pc)
Absolute magnitude (MV)1.27[4]
Details
Mass1.60[7] M☉
Luminosity18.89[6] L☉
Surface gravity (log g)3.88±0.14[7] cgs
Temperature7,395±251[7] K
Metallicity [Fe/H]0.14[4] dex
Rotational velocity (v sin i)105[8] km/s
Age959[7] Myr
Other designations
8 Aql, V1729 Aql, BD−03°4392, FK5 3500, HD 174589, HIP 92524, HR 7101, SAO 142706[9]
Database references
SIMBADdata

Abt and Morrell (1995) found a stellar classification of F0 IV[3] for this star, suggesting it is an F-type subgiant. In their 2010 study, Fox Machado et al. assigned a class of F2 III,[4] which matches an evolved giant star. It is a Delta Scuti variable with at least three overlapping pulsation frequencies.[4] The star is nearly a billion years old[7] with a relatively high rotation rate, showing a projected rotational velocity of 105 K.[8] It has 1.6[7] times the mass of the Sun and is radiating 19[6] times the Sun's luminosity from its photosphere at an effective temperature of about 7,395 K.[7]

References
  1. 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.
  2. Wielen, R.; et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, Astronomisches Rechen-Institut Heidelberg, Bibcode:1999VeARI..35....1W.
  3. Abt, Helmut A.; Morrell, Nidia I. (1995), "The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars", Astrophysical Journal Supplement, 99: 135, Bibcode:1995ApJS...99..135A, doi:10.1086/192182.
  4. Fox Machado, L.; et al. (July 2010), "Strömgren photometry and spectroscopy of the δ Scuti stars 7 Aql and 8 Aql", New Astronomy, 15 (5): 397–402, arXiv:0912.2808, Bibcode:2010NewA...15..397F, doi:10.1016/j.newast.2009.11.006.
  5. Cousins, A. W. J. (1965), "Photometric Data for Stars in the Equatorial Zone (Eighth List)", Monthly Notes of the Astronomical Society of Southern Africa, 24: 120, Bibcode:1965MNSSA..24..120C.
  6. 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.
  7. David, Trevor J.; Hillenbrand, Lynne A. (2015), "The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets", The Astrophysical Journal, 804 (2): 146, arXiv:1501.03154, Bibcode:2015ApJ...804..146D, doi:10.1088/0004-637X/804/2/146.
  8. Royer, F.; et al. (2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i in the northern hemisphere", Astronomy and Astrophysics, 393 (3): 897–911, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943.
  9. "8 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved April 25, 2019.
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