Astronomy:42 Aquilae

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Short description: Star in the constellation Aquila
42 Aquilae
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquila
Right ascension  19h 37m 47.31770s[1]
Declination −04° 38′ 51.5072″[1]
Apparent magnitude (V) 5.45[2]
Characteristics
Spectral type F3 IV/V[3]
B−V color index 0.429±0.003[2]
Astrometry
Radial velocity (Rv)−37.6±1.8[4] km/s
Proper motion (μ) RA: +105.381[1] mas/yr
Dec.: –53.557[1] mas/yr
Parallax (π)31.1671 ± 0.1422[1] mas
Distance104.6 ± 0.5 ly
(32.1 ± 0.1 pc)
Absolute magnitude (MV)2.98[5]
Details
Mass1.26[6] M
Luminosity5.76[2] L
Surface gravity (log g)4.00[6] cgs
Temperature6,749±80[4] K
Metallicity [Fe/H]0.17[4] dex
Rotational velocity (v sin i)87.0±4.4[5] km/s
Age1.283[6] Gyr
Other designations
42 Aql, BD−04° 4861, HD 185124, HIP 96556, HR 7460, SAO 143621[7]
Database references
SIMBADdata

42 Aquilae, abbreviated 42 Aql, is a single[8] star in the equatorial constellation of Aquila. 42 Aquilae is its Flamsteed designation. It is a dim star but visible to the naked eye under suitable viewing conditions, having an apparent visual magnitude of 5.45.[2] 42 Aql is located some 104.6 light years away, as determined from its annual parallax shift of 31.2 mas.[1] it is moving closer to the Earth with a heliocentric radial velocity of −38 km/s,[4] and is predicted to come to within 52 light-years of the Sun in around 752,000 years.[2]

The stellar classification of this star is F3 IV/V,[3] which matches an F-type star with blended spectral traits of a main sequence star and a subgiant star. It is around 1.3[6] billion years old with a relatively high rate of rotation, having a projected rotational velocity of 87 km/s.[5] The star has 1.26[6] times the mass of the Sun and is radiating 5.76[2] times the Sun's luminosity from its photosphere at an effective temperature of 6,749 K.[4] These coordinates are a source of X-ray emission, which is most likely (99.3% chance) coming from the star.[9]

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 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. 
  2. 2.0 2.1 2.2 2.3 2.4 2.5 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Houk, N.; Swift, C. (1999), "Michigan catalogue of two-dimensional spectral types for the HD Stars", Michigan Spectral Survey 5, Bibcode1999MSS...C05....0H. 
  4. 4.0 4.1 4.2 4.3 4.4 Casagrande, L. et al. (June 2011), "New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey", Astronomy and Astrophysics 530: A138, doi:10.1051/0004-6361/201016276, Bibcode2011A&A...530A.138C. 
  5. 5.0 5.1 5.2 Ammler-von Eiff, Matthias; Reiners, Ansgar (June 2012), "New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?", Astronomy & Astrophysics 542: A116, doi:10.1051/0004-6361/201118724, Bibcode2012A&A...542A.116A. 
  6. 6.0 6.1 6.2 6.3 6.4 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, doi:10.1088/0004-637X/804/2/146, Bibcode2015ApJ...804..146D. 
  7. "42 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=42+Aql. 
  8. Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society 389 (2): 869–879, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode2008MNRAS.389..869E. 
  9. 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.