Astronomy:19 Aquilae

From HandWiki
Short description: Star in the constellation Aquila
19 Aquilae
19 Aquilae, 2007-04-21.jpg
Image captured from Mount Laguna, California
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquila
Right ascension  19h 08m 59.90684s[1]
Declination +06° 04′ 23.4857″[1]
Apparent magnitude (V) 5.227[2]
Characteristics
Spectral type F0 III-IV[3]
Apparent magnitude (U) 5.59±0.010[4]
Apparent magnitude (B) 5.57±0.007[5]
Apparent magnitude (V) 5.23±0.009[5]
U−B color index +0.020[2]
B−V color index +0.345[2]
Variable type suspected γ Dor[6]
Astrometry
Radial velocity (Rv)−46.7[7] km/s
Proper motion (μ) RA: −5.485[1] mas/yr
Dec.: −73.785[1] mas/yr
Parallax (π)22.9563 ± 0.2397[1] mas
Distance142 ± 1 ly
(43.6 ± 0.5 pc)
Absolute magnitude (MV)1.94[8]
Details
Mass1.54[9] M
Radius2.50+0.25
−0.05
[1] R
Luminosity12.8±0.2[1] L
Surface gravity (log g)4.13[3] cgs
Temperature6,784±53[9] K
Metallicity [Fe/H]+0.03[3] dex
Rotational velocity (v sin i)57.0[10] km/s
Age2.25[9] Gyr
Other designations
19 Sge, BD+5°4040, FK5 3530, HD 178596, HIP 94068, HR 7266, SAO 124318[11]
Database references
SIMBADdata

19 Aquilae is a single[12] star located 142 light-years (44 parsecs) away from the Sun in the equatorial constellation of Aquila. 19 Aquilae is the Flamsteed designation. It is visible to the naked eye as a dim, yellow-white hued star with an apparent visual magnitude of 5.23.[2] The star is moving closer to the Earth with a heliocentric radial velocity of −46.7 km/s.[7]

This object has a stellar classification of F0 III-IV,[3] with the luminosity class matching an evolving star transitioning from the subgiant to a giant stage. Poretti et al. (2003) list it as a suspected Gamma Doradus variable, and it is located near the cooler end of the instability strip on the Hertzsprung–Russell diagram.[6] These spatial coordinates are a source of X-ray emission, which is most likely coming from the star.[13]

19 Aquilae is an estimated 2.25[9] billion years old with a moderately high rate of spin, showing a projected rotational velocity of 57.0 km/s.[10] It has 1.54[9] times the mass of the Sun and 2.50[1] times the Sun's radius. The star is radiating 12.8[1] times the luminosity of the Sun from its photosphere at an effective temperature of 6,784 K.[9]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 1.8 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. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Oja, T. (1986). "UBV photometry of stars whose positions are accurately known. III". Astronomy and Astrophysics Supplement Series 65 (2): 405–4. Bibcode1986A&AS...65..405O. 
  3. 3.0 3.1 3.2 3.3 Balachandran, Suchitra (May 1, 1990). "Lithium depletion and rotation in main-sequence stars". Astrophysical Journal, Part 1 354: 310–332. doi:10.1086/168691. Bibcode1990ApJ...354..310B. 
  4. Oja, T. (1984). "UBV photometry of stars whose positions are accurately known". Astronomy and Astrophysics Supplement Series 57: 357. Bibcode1984A&AS...57..357O. 
  5. 5.0 5.1 Oja, T. (September 1993). "UBV photometry of stars whose positions are accurately known. VII". Astronomy and Astrophysics Supplement Series 100 (3): 591–592. ISSN 0365-0138. Bibcode1993A&AS..100..591O. 
  6. 6.0 6.1 Poretti, E. et al. (2003). "Preparing the COROT space mission: Incidence and characterisation of pulsation in the lower instability strip". Astronomy and Astrophysics 406: 203–211. doi:10.1051/0004-6361:20030711. Bibcode2003A&A...406..203P. 
  7. 7.0 7.1 Wielen, R. et al. (1999). "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions". Veröffentlichungen Astronomisches Rechen-Institut Heidelberg (Astronomisches Rechen-Institut Heidelberg) 35 (35): 1. Bibcode1999VeARI..35....1W. 
  8. Holmberg, J. et al. (July 2009). "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics". Astronomy and Astrophysics 501 (3): 941–947. doi:10.1051/0004-6361/200811191. Bibcode2009A&A...501..941H. 
  9. 9.0 9.1 9.2 9.3 9.4 9.5 Luck, R. Earle (2015). "Abundances in the Local Region. I. G and K Giants". Astronomical Journal 150 (3): 88. doi:10.1088/0004-6256/150/3/88. Bibcode2015AJ....150...88L. 
  10. 10.0 10.1 Schröder, C.; Reiners, Ansgar; Schmitt, Jürgen H. M. M. (January 2009), "Ca II HK emission in rapidly rotating stars. Evidence for an onset of the solar-type dynamo", Astronomy and Astrophysics 493 (3): 1099–1107, doi:10.1051/0004-6361:200810377, Bibcode2009A&A...493.1099S, http://goedoc.uni-goettingen.de/goescholar/bitstream/handle/1/9690/aa10377-08.pdf?sequence=2 [yes|permanent dead link|dead link}}]
  11. "19 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=19+Aql. 
  12. 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. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E. 
  13. Haakonsen, Christian Bernt; Rutledge, Robert E. (September 2009). "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources". The Astrophysical Journal Supplement 184 (1): 138–151. doi:10.1088/0067-0049/184/1/138. Bibcode2009ApJS..184..138H.