Short description: Single, variable star in the constellation Aries
15 Arietis (abbreviated 15 Ari) is a single[8] 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,[8] which is just bright enough to be visible to the naked eye from dark suburban skies. An annual parallax shift of 5.84 mas[2] 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.[1] The measured angular diameter of this star is 3.67 ± 0.11 mas.[9] At the estimated distance of Delta Ophiuchi,[2] this yields a physical size of about 67 times the radius of the Sun.[10] The radius determined from the observed brightness and colour of the star is 87 R☉.[6]
15 Arietis is a short period semiregular variable with the designation AV Arietis. The period given in the General Catalogue of Variable Stars is 5.032 days.[3] Longterm photometry finds that the strongest pulsation period is 18.1 days with an amplitude of 0.028 magnitudes, while a second is 21.9 days and 0.030 in magnitude.[1]
References
- ↑ 1.0 1.1 1.2 1.3 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, doi:10.1111/j.1365-2966.2009.15588.x, Bibcode: 2009MNRAS.400.1945T.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, doi:10.1051/0004-6361:20078357, Bibcode: 2007A&A...474..653V.
- ↑ 3.0 3.1 3.2 Samus, N. N. et al. (2009). "VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013)". VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S 1. Bibcode: 2009yCat....102025S.
- ↑ 4.0 4.1 Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode: 1986EgUBV........0M.
- ↑ 5.0 5.1 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, doi:10.1051/0004-6361:20041272, Bibcode: 2005A&A...430..165F.
- ↑ 6.0 6.1 6.2 6.3 Koen, Chris; Laney, Dave (2000). "Rapidly oscillating M giant stars?". Monthly Notices of the Royal Astronomical Society 311 (3): 636. doi:10.1046/j.1365-8711.2000.03127.x. Bibcode: 2000MNRAS.311..636K.
- ↑ 7.0 7.1 McDonald, I.; Zijlstra, A. A.; Boyer, M. L. (2012). "Fundamental parameters and infrared excesses of Hipparcos stars". Monthly Notices of the Royal Astronomical Society 427 (1): 343–357. doi:10.1111/j.1365-2966.2012.21873.x. Bibcode: 2012MNRAS.427..343M.
- ↑ 8.0 8.1 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, doi:10.1111/j.1365-2966.2008.13596.x, Bibcode: 2008MNRAS.389..869E.
- ↑ Richichi, A.; Percheron, I.; Khristoforova, M. (February 2005), "CHARM2: An updated Catalog of High Angular Resolution Measurements", Astronomy and Astrophysics 431 (2): 773–777, doi:10.1051/0004-6361:20042039, Bibcode: 2005A&A...431..773R.
- ↑ Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library, 1 (3rd ed.), Birkhäuser, ISBN 3-540-29692-1, https://books.google.com/books?id=OvTjLcQ4MCQC&pg=PA41. . The radius (R*) is given by:
- [math]\displaystyle{ \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} }[/math]
External links
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