15 Arietis

15 Arietis
Observation data
Epoch J2000      Equinox J2000
Constellation Aries
Right ascension 02h 10m 37.59642s[1]
Declination +19° 30′ 01.2099″[1]
Apparent magnitude (V) 5.74[2]
Characteristics
Spectral type M3 III[3]
U−B color index +1.91[4]
B−V color index +1.64[4]
Variable type Pulsating
Astrometry
Radial velocity (Rv)+62.04 ± 0.22[5] km/s
Proper motion (μ) RA: +87.88[1] mas/yr
Dec.: -27.82[1] mas/yr
Parallax (π)5.84 ± 0.49[1] mas
Distance560 ± 50 ly
(170 ± 10 pc)
Details
Radius67[6] R☉
Other designations
AV Arietis, BD+18 277, FK5 1056, HD 13325, HIP 10155, HR 631, SAO 92822.[4]

15 Arietis (abbreviated 15 Ari) is a single[2] variable star in the northern constellation of Aries. 15 Arietis is the Flamsteed designation; it also bears the variable star designation AV Arietis. It has an apparent visual magnitude of 5.74,[2] which is just bright enough to be visible to the naked eye from dark suburban skies. An annual parallax shift of 5.84 mas[1] corresponds to a physical distance of approximately 560 light-years (170 parsecs) from Earth. At that distance, the star's brightness is reduced by 0.33[5] in magnitude because of extinction from interstellar gas and dust.

This is a red giant star with a stellar classification of M3 III.[3] The measured angular diameter of this star is 3.67 ± 0.11 mas.[7] At the estimated distance of Delta Ophiuchi,[1] this yields a physical size of about 67 times the radius of the Sun.[6] It is a pulsating variable; the first pulsation period is 18.1 days with an amplitude of 0.028 magnitudes, while the second is 21.9 days and 0.030 in magnitude.[3]

References

  1. 1 2 3 4 5 6 7 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.
  2. 1 2 3 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
  3. 1 2 3 Tabur, V.; et al. (December 2009), "Long-term photometry and periods for 261 nearby pulsating M giants", Monthly Notices of the Royal Astronomical Society 400 (4): 1945–1961, arXiv:0908.3228, Bibcode:2009MNRAS.400.1945T, doi:10.1111/j.1365-2966.2009.15588.x.
  4. 1 2 3 "AV Ari -- Semi-regular pulsating Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), retrieved 2012-07-18.
  5. 1 2 Famaey, B.; et al. (January 2005), "Local kinematics of K and M giants from CORAVEL/Hipparcos/Tycho-2 data. Revisiting the concept of superclusters", Astronomy and Astrophysics 430 (1): 165–186, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272.
  6. 1 2 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1.. The radius (R*) is given by:
    \begin{align} 2\cdot R_* & = \frac{(170\cdot 3.67\cdot 10^{-3})\ \text{AU}}{0.0046491\ \text{AU}/R_{\bigodot}} \\ & \approx 134\cdot R_{\bigodot} \end{align}
  7. ↑ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431: 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039.

External links

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