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. 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. 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. 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. 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. 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