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 1,160 light years away.
 A visual band light curve for Y Lyncis, adapted from Percy et al. (2001).[1] The top panel shows the brightness variation over a period of several years, and the lower panel shows shorter time scale variations. | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Lynx |
| Right ascension | 07h 28m 11.61657s[2] |
| Declination | +45° 59′ 26.2295″[2] |
| Apparent magnitude (V) | 6.2 - 8.9[3] |
| Characteristics | |
| Spectral type | M6S Ib[4] |
| Variable type | SRc[4] |
| Astrometry | |
| Radial velocity (Rv) | 5.50±0.6[5] km/s |
| Proper motion (μ) | RA: −1.278[2] mas/yr Dec.: −4.067[2] mas/yr |
| Parallax (π) | 2.8068 ± 0.1138 mas[2] |
| Distance | 1,160 ± 50 ly (360 ± 10 pc) |
| Details | |
| Mass | 1.5 - 2.0[3] M☉ |
| Radius | 580[3] R☉ |
| Luminosity | 10,765[6] L☉ |
| Surface gravity (log g) | 0.0[7] cgs |
| Temperature | 3,200[7] K |
| Metallicity [Fe/H] | −0.19[7] dex |
| Other designations | |
| Database references | |
| SIMBAD | data |
Y Lyncis ranges in brightness from magnitude 6.2 to 8.9. Its changes in brightness are complex with at least two different periods showing. The General Catalogue of Variable Stars lists a period of 110 days.[8] 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.[9]
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.[10] 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.[6]
References
edit- ^ Percy, John R.; Wilson, Joseph B..; Henry, Gregory W. (August 2001). "Long-Term VRI Photometry of Small-Amplitude Red Variables. I. Light Curves and Periods". Publications of the Astronomical Society of the Pacific. 113 (786): 983–996. Bibcode:2001PASP..113..983P. doi:10.1086/322153. S2CID 14609175.
- ^ a b c d e Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c 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.
- ^ a b 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): 1721–1734. arXiv:astro-ph/0608438. Bibcode:2006MNRAS.372.1721K. doi:10.1111/j.1365-2966.2006.10973.x. S2CID 5203133.
- ^ Gontcharov, G. A. (November 2006). "Pulkovo Compilation of Radial Velocities for 35,495 Hipparcos stars in a common system". Astronomy Letters. 32 (11): 759–771. arXiv:1606.08053. Bibcode:2006AstL...32..759G. doi:10.1134/S1063773706110065. eISSN 1562-6873. ISSN 1063-7737. S2CID 119231169.
- ^ a b 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): 675–684. arXiv:0806.4591. Bibcode:2008A&A...488..675G. doi:10.1051/0004-6361:200809932. S2CID 14294870.
- ^ a b c Soubiran, Caroline; Le Campion, Jean-François; Brouillet, Nathalie; Chemin, Laurent (2016). "The PASTEL catalogue: 2016 version". Astronomy & Astrophysics. 591: A118. arXiv:1605.07384. Bibcode:2016A&A...591A.118S. doi:10.1051/0004-6361/201628497. S2CID 119258214.
- ^ 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 (1): 11. Bibcode:2009JRASC.103...11P.
- ^ Guandalini, R.; Busso, M. (2008). "Infrared photometry and evolution of mass-losing AGB stars". Astronomy and Astrophysics. 488 (2): 675–684. arXiv:0806.4591. Bibcode:2008A&A...488..675G. doi:10.1051/0004-6361:200809932. S2CID 14294870.