Y Lyncis
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Lynx |
| Right ascension | 07h 28m 11.61802s[1] |
| Declination | +45° 59′ 26.2366″[1] |
| Apparent magnitude (V) | 6.2 - 8.9[2] |
| Characteristics | |
| Spectral type | M6S Ib[3] |
| Variable type | SRc[3] |
| Astrometry | |
| Radial velocity (Rv) | 5.50 ± 0.6 km/s |
| Proper motion (μ) | RA: 0.23 ± 1.17[1] mas/yr Dec.: −3.41 ± 0.60[1] mas/yr |
| Parallax (π) | 3.95 ± 0.95[1] mas |
| Distance | approx. 800 ly (approx. 250 pc) |
| Details | |
| Mass | 1.5 - 2.0[2] M☉ |
| Radius | 580[2] R☉ |
| Luminosity | 10,765[4] L☉ |
| Surface gravity (log g) | 0.0[5] cgs |
| Temperature | 3,200[5] K |
| Metallicity [Fe/H] | −0.19[5] dex |
| Other designations | |
Y Lyncis is a semiregular variable star in the constellation Lynx. It is an asymptotic giant branch star of spectral type M6S, with a luminosity class of Ib, indicating a supergiant luminosity. It is around 800 light years away.
Y Lyncis ranges in brightness from magnitude 6.8 to 8.9. Its changes in brightness are complex with at least two different periods showing. The General Catalogue of Variable Starslists a period of 110 days.[6] More recent studies show a primary pulsation period of 133 days, with and a long secondary period with an amplitude of 0.2 magnitudes and duration 1,300 days. The long secondary period variations are possibly caused by long-lived convection cells.[7]
Y Lyncis has a mass around 1.5-2.0 M☉ and a luminosity around 10,000 L☉. It is a thermally pulsing asymptotic giant branch star, an evolved star with a carbon-oxygen core that is fusing helium in a shell and hydrogen in a separate shell.[8] It is also an S-type star, where third dredge-ups have brought some carbon to the surface, but not enough to create a carbon star.[4]
References
- 1 2 3 4 5 van Leeuwen, F. (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. - 1 2 3 Szatmary, Karoly; Vinko, Jozsef (1992). "Periodicities of the light curve of the semiregular variable star Y Lyncis". Monthly Notices of the Royal Astronomical Society. 256 (2): 321–28. Bibcode:1992MNRAS.256..321S. doi:10.1093/mnras/256.2.321.
- 1 2 Kiss, L. L.; Szabó, Gy. M.; Bedding, T. R. (2006). "Variability in red supergiant stars: Pulsations, long secondary periods and convection noise". Monthly Notices of the Royal Astronomical Society. 372 (4): 1721. arXiv:astro-ph/0608438. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x.
- 1 2 Guandalini, R.; Busso, M. (2008). "Infrared photometry and evolution of mass-losing AGB stars. II. Luminosity and colors of MS and S stars". Astronomy and Astrophysics. 488 (2): 675. arXiv:0806.4591. Bibcode:2008A&A...488..675G. doi:10.1051/0004-6361:200809932.
- 1 2 3 Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497.
- ↑ Samus, N. N.; Durlevich, O. V.; 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.
- ↑ Percy, John R.; Sato, Hiromitsu (2009). "Long Secondary Periods in Pulsating Red Supergiant Stars". Journal of the Royal Astronomical Society of Canada. 103: 11. Bibcode:2009JRASC.103...11P.
- ↑ Guandalini, R.; Busso, M. (2008). "Infrared photometry and evolution of mass-losing AGB stars". Astronomy and Astrophysics. 488 (2): 675. doi:10.1051/0004-6361:200809932.