Astronomy:28 Aquilae

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Short description: Star in the constellation Aquila
28 Aquilae
V1208AqlLightCurve.png
A light curve for V1208 Aquilae, plotted from Hipparcos data[1]
Observation data
Equinox J2000.0]] (ICRS)
Constellation Aquila
Right ascension  19h 19m 39.34802s[2]
Declination +12° 22′ 28.8457″[2]
Apparent magnitude (V) 5.51 - 5.56[3]
Characteristics
Spectral type F0 III[4]
U−B color index +0.182[5]
B−V color index +0.257[5]
Variable type δ Sct[3]
Astrometry
Radial velocity (Rv)+4.36[4] km/s
Proper motion (μ) RA: +4.249[2] mas/yr
Dec.: +16.199[2] mas/yr
Parallax (π)9.5836 ± 0.0768[2] mas
Distance340 ± 3 ly
(104.3 ± 0.8 pc)
Absolute magnitude (MV)+0.46[6]
Details
Mass2.4[2] M
Radius4.8[2] R
Luminosity54.20[6] L
Surface gravity (log g)3.41[7] cgs
Temperature7,250[4] K
Metallicity [Fe/H]−0.16[4] dex
Rotational velocity (v sin i)57[8] km/s
Age655[2] Myr
Other designations
28 Aql, V1208 Aql, BD+12°3879, HD 181333, HIP 94982, HR 7331, SAO 104722[9]
Database references
SIMBADdata

28 Aquilae, abbreviated 28 Aql, is a star in the equatorial constellation of Aquila. 28 Aquilae is its Flamsteed designation though it also bears the Bayer designation A Aquilae, and the variable star designation V1208 Aquilae. It has an apparent visual magnitude is 5.5,[4] making this a faint star that requires dark suburban skies to view (according to the Bortle Dark-Sky Scale). The annual parallax shift of 9.6 mas means this star is located at a distance of approximately 340 light-years (100 parsecs) from Earth.

The spectrum of this star matches a stellar classification of F0 III.[4] Despite consistent spectral classifications as a giant star,[10] models show that it is just reaching the end of its main sequence lifetime at an age of 655 million years.[2]

The variability of 28 Aquilae was discovered by Michel Breger in 1969. It was revealed to be a Delta Scuti-type pulsating variable star with at least two periods of pulsation. The known periods have frequencies of 6.68 and 7.12 cycles per day.[11] The outer atmosphere has an effective temperature of 7,250 K,[4] which lies in the range of a yellow-white hued F-type star.[12]

References

  1. Light Curve, ESA, https://www.cosmos.esa.int/web/hipparcos/java-tools/light-curve, retrieved 17 February 2022. 
  2. Jump up to: 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  3. Jump up to: 3.0 3.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode2017ARep...61...80S. 
  4. Jump up to: 4.0 4.1 4.2 4.3 4.4 4.5 4.6 Luck, R. Earle; Heiter, Ulrike (June 2007), "Giants in the Local Region", The Astronomical Journal 133 (6): 2464–2486, doi:10.1086/513194, Bibcode2007AJ....133.2464L. 
  5. Jump up to: 5.0 5.1 Breger, M. (March 1968), "UBV and narrow-band UVBY photometry of bright stars", Astronomical Journal 73: 84–85, doi:10.1086/110602, Bibcode1968AJ.....73...84B. 
  6. Jump up to: 6.0 6.1 Anderson, E.; Francis, Ch. (2012), "XHIP: An extended hipparcos compilation", Astronomy Letters 38 (5): 331, doi:10.1134/S1063773712050015, Bibcode2012AstL...38..331A. 
  7. Soubiran, C. et al. (June 2010), "The PASTEL catalogue of stellar parameters", Astronomy and Astrophysics 515: A111, doi:10.1051/0004-6361/201014247, Bibcode2010A&A...515A.111S. 
  8. Royer, F. et al. (October 2002), "Rotational velocities of A-type stars in the northern hemisphere. II. Measurement of v sin i", Astronomy and Astrophysics 393: 897–911, doi:10.1051/0004-6361:20020943, Bibcode2002A&A...393..897R. 
  9. "* 28 Aql". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=%2A+28+Aql. 
  10. Skiff, B. A. (2014), "VizieR Online Data Catalog: Catalogue of Stellar Spectral Classifications (Skiff, 2009–2016)", VizieR On-line Data Catalog, Bibcode2014yCat....1.2023S. 
  11. Dall, T. H.; Frandsen, S. (May 2002), "Mode characterisation in delta Scuti stars. I. rho Pup, GN And, V1208 Aql and AV Cet", Astronomy and Astrophysics 386 (3): 964–970, doi:10.1051/0004-6361:20020357, Bibcode2002A&A...386..964D. 
  12. "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16. 

External links