19 Arietis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Aries |
| Right ascension | 02h 13m 03.30440s[1] |
| Declination | +15° 16′ 47.5005″[1] |
| Apparent magnitude (V) | 5.70[2] |
| Characteristics | |
| Spectral type | M0 III[3] |
| U−B color index | +1.95[2] |
| B−V color index | +1.55[2] |
| R−I color index | 0.97 |
| Variable type | Semiregular[4] |
| Astrometry | |
| Radial velocity (Rv) | 21.11 ± 0.26[5] km/s |
| Proper motion (μ) | RA: +97.95[1] mas/yr Dec.: -20.30[1] mas/yr |
| Parallax (π) | 6.81 ± 0.38[1] mas |
| Distance | 480 ± 30 ly (147 ± 8 pc) |
| Details | |
| Radius | 39[6] R☉ |
| Temperature | 3,690[7] K |
| Metallicity [Fe/H] | –0.02 ± 0.11[8] dex |
| Other designations | |
19 Arietis is the Flamsteed designation for a star in the northern constellation of Aries. It has an apparent visual magnitude of 5.70,[2] which means it is faintly visible to the naked eye. Based upon an annual parallax shift of 6.81 mas,[1] it is approximately 480 light-years (150 parsecs) away from Earth. At that distance, the brightness of the star is diminished by 0.21 in magnitude from extinction caused by interstellar gas and dust.[5]
This is a red giant star with a stellar classification of M0 III.[3] It is a semi-regular variable with periods of 32 and 275 days; the brightness of the star changes by an amplitude of 0.14 in magnitude during those intervals.[4] The measured angular diameter of this star, after correction for limb darkening, is 2.44 ± 0.03 mas.[10] At the estimated distance of Delta Ophiuchi,[1] this yields a physical size of about 39 times the radius of the Sun.[6] The effective temperature of the outer envelope is 3,690 K,[7] giving it the cool reddish glow of an M-type star.[11]
References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 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.
- ↑ 2.0 2.1 2.2 2.3 Johnson, H. L. et al. (1966), "UBVRIJKL photometry of the bright stars", Communications of the Lunar and Planetary Laboratory 4 (99), Bibcode:1966CoLPL...4...99J.
- ↑ 3.0 3.1 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, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x.
- ↑ 4.0 4.1 Yeşilyaprak, C.; Aslan, Z. (December 2004), "Period-luminosity relation for M-type semiregular variables from Hipparcos parallaxes", Monthly Notices of the Royal Astronomical Society 355 (2): 601–607, arXiv:0704.3150, Bibcode:2004MNRAS.355..601Y, doi:10.1111/j.1365-2966.2004.08344.x.
- ↑ 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, arXiv:astro-ph/0409579, Bibcode:2005A&A...430..165F, doi:10.1051/0004-6361:20041272.
- ↑ 6.0 6.1 Lang, Kenneth R. (2006), Astrophysical formulae, Astronomy and astrophysics library 1 (3 ed.), Birkhäuser, ISBN 3-540-29692-1.. The radius (R*) is given by:
- Failed to parse(unknown function '\begin'): {\begin{aligned}2\cdot R_{*}&={\frac {(147\cdot 2.44\cdot 10^{{-3}})\ {\text{AU}}}{0.0046491\ {\text{AU}}/R_{{\bigodot }}}}\\&\approx 77.2\cdot R_{{\bigodot }}\end{aligned}}
- ↑ 7.0 7.1 Wittkowski, M. et al. (December 2006), "Tests of stellar model atmospheres by optical interferometry. IV. VINCI interferometry and UVES spectroscopy of Menkar", Astronomy and Astrophysics 460 (3): 855–864, arXiv:astro-ph/0610150, Bibcode:2006A&A...460..855W, doi:10.1051/0004-6361:20066032.
- ↑ Taylor, B. J. (February 1999), "Catalogs of temperatures and [Fe/H] averages for evolved G and K stars", Astronomy and Astrophysics Supplement 134: 523–524, Bibcode:1999A&AS..134..523T, doi:10.1051/aas:1999153.
- ↑ "19 Ari -- Variable Star", SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), retrieved 2012-07-18.
- ↑ Richichi; 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.
- ↑ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, retrieved 2012-01-16
External links
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