38 Arietis

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38 Arietis
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 02h 44m 57.57945s[1]
Declination +12° 26′ 44.7297″[1]
Apparent magnitude (V) +5.178[2]
Spectral type A7 III-IV[3]
U−B color index +0.121[2]
B−V color index +0.235[2]
Variable type δ Sct[4]
Radial velocity (Rv) -1.5[5] km/s
Proper motion (μ) RA: +120.49[1] mas/yr
Dec.: -85.78[1] mas/yr
Parallax (π) 27.52 ± 0.40[1] mas
Distance 119 ± 2 ly
(36.3 ± 0.5 pc)
Absolute magnitude (MV) 2.22[6]
Radius 2.1[7] R
Luminosity 11[6] L
Surface gravity (log g) 4.04[6] cgs
Temperature 7,638[6] K
Rotational velocity (v sin i) 86[8] km/s
Age 0.58[9] Gyr
Other designations
UV Arietis, BD+11° 377, HD 17093, HIP 12832, HR 812, SAO 93083.[10]
Database references

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,[11] forming part of the neighboring constellation of Cetus. With an apparent visual magnitude of +5.18,[2] it is bright enough to be viewed with the naked eye. The measured annual parallax shift of 27.52 mas[1] 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,[3] 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.[4] This star is larger than the Sun, with more than double the Sun's radius and 11 times the luminosity.[6] This energy is being radiated into outer space from the atmosphere at an effective temperature of 7,638 K,[6] giving it the white-hued glow of an A-type star.


  1. ^ 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:0708.1752Freely accessible, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. 
  2. ^ a b c d Gutierrez-Moreno, Adelina; et al. (1966), A System of photometric standards, 1, Publicaciones Universidad de Chile, Department de Astronomy, pp. 1–17, Bibcode:1966PDAUC...1....1G. 
  3. ^ 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. 
  4. ^ 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, 144: 469–474, Bibcode:2000A&AS..144..469R, doi:10.1051/aas:2000221. 
  5. ^ Wilson, R. E. (1953), General Catalogue of Stellar Radial Velocities, Carnegie Institute of Washington D.C., Bibcode:1953GCRV..C......0W. 
  6. ^ 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: 515–528, arXiv:astro-ph/0207494Freely accessible, Bibcode:2002A&A...392..515P, doi:10.1051/0004-6361:20020854. 
  7. ^ 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/0012289Freely accessible. Bibcode:2001A&A...367..521P. doi:10.1051/0004-6361:20000451. 
  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, arXiv:astro-ph/0205255Freely accessible, Bibcode:2002A&A...393..897R, doi:10.1051/0004-6361:20020943. 
  9. ^ Vican, Laura (June 2012), "Age Determination for 346 Nearby Stars in the Herschel DEBRIS Survey", The Astronomical Journal, 143 (6): 135, arXiv:1203.1966Freely accessible, Bibcode:2012AJ....143..135V, doi:10.1088/0004-6256/143/6/135. 
  10. ^ "38 Ari". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2012-07-18. 
  11. ^ 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. 

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