Y Carinae (Y Car) is a Classical Cepheid variable, a type of variable star, in the constellation Carina. Its apparent magnitude varies from 7.53 to 8.48.
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Carina |
| Right ascension | 10h 33m 10.85133s[2] |
| Declination | −58° 29′ 55.0959″[2] |
| Apparent magnitude (V) | 8.16[3] (7.53 – 8.48[4]) |
| Characteristics | |
| Spectral type | F0/3[5] + B9V[6] |
| B−V color index | +0.59[3] |
| Variable type | Classical Cepheid[4] |
| Astrometry | |
| Radial velocity (Rv) | −12.90[7] km/s |
| Proper motion (μ) | RA: −5.83[2] mas/yr Dec.: 3.21[2] mas/yr |
| Parallax (π) | 0.3011 ± 0.0358 mas[8] |
| Distance | approx. 11,000 ly (approx. 3,300 pc) |
| Absolute magnitude (MV) | −3.0[9] |
| Orbit[9] | |
| Primary | A |
| Companion | B |
| Period (P) | 1006.9 days |
| Eccentricity (e) | 0.437 |
| Semi-amplitude (K1) (primary) | 10.0 km/s |
| Details | |
| A | |
| Mass | 4.9[10] M☉ |
| Luminosity | 1,250[9] L☉ |
| Surface gravity (log g) | 1.800[3] cgs |
| Temperature | 5,800[9] K |
| Metallicity | −0.230[3] |
| Other designations | |
| Database references | |
| SIMBAD | data |
The primary Cepheid pulsation period is 3.6 days, but it also pulsates with a secondary period of 2.56 days. It is known as a double-mode Cepheid, or a beat Cepheid since the two periods interfere to produce slow variations at a beat frequency.[9]
The variable primary star is in a triple system with a very close pair of hot main sequence stars. The period of the outer pair is 2.76 years. The inner pair are constrained to orbit in less than 31 days, but the exact nature of the orbit is unknown. The existence of the close binary pair throws into doubt previous calculations of the mass of the pulsating star. The existence of high numbers of triple systems and short period Cepheids suggests that some at least of the short period Cepheids may have formed by mergers.[11]
References
edit- ^ "Hipparcos Tools Interactive Data Access". Hipparcos. ESA. Retrieved 8 December 2021.
- ^ a b c d 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. S2CID 18759600.
- ^ a b c d Soubiran, C.; Le Campion, J.-F.; Cayrel De Strobel, G.; Caillo, A. (2010). "The PASTEL catalogue of stellar parameters". Astronomy and Astrophysics. 515: A111. arXiv:1004.1069. Bibcode:2010A&A...515A.111S. doi:10.1051/0004-6361/201014247. S2CID 118362423.
- ^ a b 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.
- ^ Houk, Nancy (1975). Michigan catalogue of two-dimensional spectral types for the HD stars. Vol. 1. Ann Arbor, Michigan: Dept. of Astronomy, University of Michigan. Bibcode:1975MSS...C01....0H.
- ^ Evans, Nancy R. (1992). "The Luminosity of the Double-Mode Cepheid y Carinae". The Astrophysical Journal. 385: 680. Bibcode:1992ApJ...385..680E. doi:10.1086/170974.
- ^ Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; Levato, H.; Morrell, N. I.; Torres, G.; Udry, S. (2004). "SB9: The ninth catalogue of spectroscopic binary orbits". Astronomy and Astrophysics. 424 (2): 727–732. arXiv:astro-ph/0406573. Bibcode:2004A&A...424..727P. doi:10.1051/0004-6361:20041213. S2CID 119387088.
- ^ Brown, A. G. A.; et al. (Gaia collaboration) (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics. 616. A1. arXiv:1804.09365. Bibcode:2018A&A...616A...1G. doi:10.1051/0004-6361/201833051. Gaia DR2 record for this source at VizieR.
- ^ a b c d e Bohm-Vitense, E.; Evans, N. R.; Carpenter, K.; Morgan, S.; Beck-Winchatz, B.; Robinson, R. (1997). "The dynamical mass of the beat cepheid Y carinae and stellar opacities". The Astronomical Journal. 114: 1176. Bibcode:1997AJ....114.1176B. doi:10.1086/118549.
- ^ Evans, Nancy Remage; Berdnikov, Leonid; Lauer, Jennifer; Morgan, Douglas; Nichols, Joy; Günther, H. Moritz; Gorynya, Natalya; Rastorguev, Alexey; Moskalik, Pawel (2015). "Binary Properties from Cepheid Radial Velocities (CRaV)". The Astronomical Journal. 150 (1): 13. arXiv:1505.05823. Bibcode:2015AJ....150...13E. doi:10.1088/0004-6256/150/1/13. S2CID 54943097.
- ^ Evans, Nancy Remage; Carpenter, Kenneth G.; Robinson, Richard; Kienzle, Francesco; Dekas, Anne E. (2005). "High-Mass Triple Systems: The Classical Cepheid Y Carinae". The Astronomical Journal. 130 (2): 789–793. arXiv:astro-ph/0504169. Bibcode:2005AJ....130..789E. doi:10.1086/430458. S2CID 119342828.