Jump to content

38 Arietis

From Wikipedia, the free encyclopedia
(Redirected from HR 812)
38 Arietis

Four visual band light curves for 38 Arietis, adapted from Valtier et al. (1974)[1]
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 02h 44m 57.57945s[2]
Declination +12° 26′ 44.7297″[2]
Apparent magnitude (V) +5.178[3]
Characteristics
Spectral type A7 III-IV[4]
U−B color index +0.121[3]
B−V color index +0.235[3]
Variable type δ Sct[5]
Astrometry
Radial velocity (Rv)-1.5[6] km/s
Proper motion (μ) RA: +120.49[2] mas/yr
Dec.: -85.78[2] mas/yr
Parallax (π)27.52 ± 0.40 mas[2]
Distance119 ± 2 ly
(36.3 ± 0.5 pc)
Absolute magnitude (MV)2.22[7]
Details
Radius2.1[8] R
Luminosity11[7] L
Surface gravity (log g)4.04[7] cgs
Temperature7,638[7] K
Rotational velocity (v sin i)86[9] km/s
Age0.58[10] Gyr
Other designations
UV Arietis, BD+11° 377, HD 17093, HIP 12832, HR 812, SAO 93083.[11]
Database references
SIMBADdata

38 Arietis (abbreviated 38 Ari) is a variable star in the northern constellation of Aries. 38 Arietis is the Flamsteed designation. It was once designated 88 Ceti,[12] forming part of the neighboring constellation of Cetus. With an apparent visual magnitude of +5.18,[3] it is bright enough to be viewed with the naked eye. The measured annual parallax shift of 27.52 mas[2] is equivalent to a distance of approximately 119 light-years (36 parsecs) from Earth.

The spectrum of this star matches a stellar classification of A7 III-IV,[4] with the luminosity class of III-IV indicating it shows traits part way between the subgiant and giant star stages of its evolution. It is a Delta Scuti variable with a period of 0.0355 days (51 minutes) and a magnitude change of 0.040.[5] This star is larger than the Sun, with more than double the Sun's radius and 11 times the luminosity.[7] This energy is being radiated into outer space from the atmosphere at an effective temperature of 7,638 K,[7] giving it the white-hued glow of an A-type star.

References

[edit]
  1. ^ Valtier, J. C.; Sareyan, J. P.; Le Contel, J. M.; Zribi, G. (January 1974). "Photometric observations of delta Scuti stars. II. HR 432, HR 515, HR 812". Astronomy & Astrophysics Supplement Series. 18: 235–249. Retrieved 28 October 2021.
  2. ^ a b c d e f van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
  3. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), "A System of photometric standards", Publications of the Department of Astronomy University of Chile, 1, Publicaciones Universidad de Chile, Department de Astronomy: 1–17, Bibcode:1966PDAUC...1....1G.
  4. ^ a b Cowley, A.; et al. (April 1969), "A study of the bright A stars. I. A catalogue of spectral classifications", Astronomical Journal, 74: 375–406, Bibcode:1969AJ.....74..375C, doi:10.1086/110819.
  5. ^ a b Rodríguez, E.; López-González, M. J.; López de Coca, P. (June 2000), "A revised catalogue of delta Sct stars", Astronomy and Astrophysics Supplement Series, 144 (3): 469–474, Bibcode:2000A&AS..144..469R, doi:10.1051/aas:2000221, hdl:10261/226673.
  6. ^ Wilson, R. E. (1953), "General Catalogue of Stellar Radial Velocities", Carnegie Institute Washington D.C. Publication, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W.
  7. ^ a b c d e f Paunzen, E.; et al. (September 2002), "On the Period-Luminosity-Colour-Metallicity relation and the pulsational characteristics of lambda Bootis type stars", Astronomy and Astrophysics, 392 (2): 515–528, arXiv:astro-ph/0207494, Bibcode:2002A&A...392..515P, doi:10.1051/0004-6361:20020854, S2CID 54666586.
  8. ^ Pasinetti Fracassini, L. E.; Pastori, L.; Covino, S.; Pozzi, A. (February 2001). "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third edition - Comments and statistics". Astronomy and Astrophysics. 367 (2): 521–524. arXiv:astro-ph/0012289. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. S2CID 425754.
  9. ^ 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, arXiv:astro-ph/0205255, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943, S2CID 14070763.
  10. ^ Vican, Laura (June 2012), "Age Determination for 346 Nearby Stars in the Herschel DEBRIS Survey", The Astronomical Journal, 143 (6): 135, arXiv:1203.1966, Bibcode:2012AJ....143..135V, doi:10.1088/0004-6256/143/6/135, S2CID 118539505.
  11. ^ "38 Ari". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-18.
  12. ^ Wagman, M. (August 1987), "Flamsteed's Missing Stars", Journal for the History of Astronomy, 18 (3): 215, Bibcode:1987JHA....18..209W, doi:10.1177/002182868701800305, S2CID 118445625.
[edit]