RS Canum Venaticorum
| Observation data Epoch J2000.0 Equinox J2000.0 | ||
|---|---|---|
| Constellation | Canes Venatici | |
| Right ascension | 13h 10m 36.908s[2] | |
| Declination | +35° 56′ 05.58″[2] | |
| Apparent magnitude (V) | 7.93[3] to 9.14 (secondary: 8.19)[4] | |
| Characteristics | ||
| A | ||
| Evolutionary stage | Main-sequence[5]
| |
| Spectral type | F6IV[6] or F5V[5] | |
| B−V color index | 0.46[7] | |
| B | ||
| Evolutionary stage | Subgiant[5] | |
| Spectral type | G8IV[6] or K2IV[5] | |
| B−V color index | 0.91[7] | |
| Variable type | Algol and RS CVn[4] | |
| Absolute magnitude (MV) | 2.95[9] | |
Semi-amplitude (K1)(primary) | 90.2±0.1 km/s | |
| Semi-amplitude (K2) (secondary) | 84.3 km/s | |
| Details Rotational velocity (v sin i)42±3 km/s | | |
| Database references | ||
| SIMBAD | data | |
RS Canum Venaticorum is a
light years from the Sun based on parallax,[2] but is drifting closer with a net radial velocity of −14 km/s.[8] Olin J. Eggen (1991) included this system as a member of the IC 2391 supercluster,[7] but it was later excluded.[12]
Variability
The variable nature of RS Canum Venaticorum was discovered by the Russian astronomer
eclipsing binary. Some of the brightness variations are caused by large spots on the surface of the star. Similar variable stars are known as RS Canum Venaticorum variables.[10]
Some RS Canum Venaticorum variables, including this star, also undergo eclipses. The primary eclipse minimum decreases the visual brightness of the system by 1.21 magnitudes, while the secondary minimum decreases it by 0.26 magnitudes.[3] The exact magnitudes vary somewhat due to the inherent variability of the secondary. The General Catalogue of Variable Stars lists magnitude 8.19 for the secondary minimum and 9.14 for the primary minimum.[4]
Components
The primary component is a relatively inactive
projected rotational velocity of about 11 km/s. That rate is slower than expected if the rotation of the star were locked with its orbital period. It has an estimated age of 2.5 billion years.[5]
The secondary component is a
Sun's radius and a relatively high rotation rate with a projected rotational velocity of 42 km/s.[10] This rapid spin was likely driven by interaction with the primary, and it generates the surface magnetic activity that makes the star variable.[14] As with the Sun, it is undergoing differential rotation.[10]
Lower temperature
starspots cover a significant fraction of the secondary's surface, causing light variation as the star rotates.[15] These are found at several active latitudes on the star below 70°, and appear to migrate at the rate of 0.1° per day.[10] The total amount of spots varies in intensity with a cycle of 19.7±1.9 years, ranging from 17% to 37% coverage of the surface.[1] The luminosity also varies slightly (0.01) due to proximity and reflection from the primary star.[5] X-ray emission has been detected from this star with a luminosity of 2.14×1031 erg s−1.[10] It has also been detected in the radio band.[16]
References
- ^ Bibcode:1995A&A...301...75R
- ^ .
- ^ hdl:10995/73280
- ^ S2CID 125853869
- ^ S2CID 117824595
- ^ Bibcode:1990A&A...230..389S
- ^ doi:10.1086/116025
- ^ S2CID 15290475
- S2CID 119257644
- ^
- ^ "RS CVn". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2020-11-05.
- doi:10.1086/117734
- Bibcode:1930CoPri..11...21S
- ISBN 9781139463287
- doi:10.1086/116717
- S2CID 119455647
Further reading
- Rodonò, M.; et al. (May 2001), "On the determination of the light curve parameters of detached active binaries. I. The prototype RS Canum Venaticorum", Astronomy and Astrophysics, 371: 174–185,
- Heckert, Paul A.; Ordway, James I. (May 1995), "Long Term SPOT Activity on Eclipsing RS CVn Stars: RS CVn, SS Boo, and MM HER", Astronomical Journal, 109: 2169, doi:10.1086/117442
- Hall, D. S. (1994), "The active dynamo stars RS Cvn, BY Dra, FK Com, Algol, W UMa and T Tau.", Memorie della Societa Astronomica Italiana, 65: 73–82, Bibcode:1994MmSAI..65...73H
- Reglero, V.; Gimenez, A.; Estela, A. (May 1990), "The active eclipsing binary RS Canum Venaticorum", Astronomy and Astrophysics, 231: 375–382, Bibcode:1990A&A...231..375R
- Srivastava, J. B.; Kandpal, C. D. (January 1990), "UBV observations of RS canum venaticorum", Astrophysics and Space Science, 163 (2): 217–222, S2CID 120290630
- Gimenez, A.; et al. (July 1990), "Ultraviolet to near-infrared continuum flux distribution in the active binary RS canum venaticorum", Astrophysics and Space Science, 169 (1–2): 233–236, S2CID 120407496
- Drake, Stephen A.; et al. (December 1989), "A Survey of the Radio Continuum Emission of RS Canum Venaticorum and Related Active Binary Systems", Astrophysical Journal Supplement, 71: 905, doi:10.1086/191402
- Srivastava, R. K. (October 1987), "Photoelectric Observations and the Wave Minimum of Rs-Canum", Astrophysics and Space Science, 137 (1): 63–72, S2CID 120691917
- Kang, Y. W.; Wilson, R. E. (June 1984), "Starspot Cycle of RS CVn", Bulletin of the American Astronomical Society, 16: 726, Bibcode:1984BAAS...16..726K
- Evren, S.; et al. (January 1980), "New Light Curves of RS CVn", Information Bulletin on Variable Stars, 1732: 1, Bibcode:1980IBVS.1732....1E
- Eaton, J. A.; et al. (November 1980), "A Sudden Acceleration in the Migration Rate of RS CVn", Information Bulletin on Variable Stars, 1862: 1, Bibcode:1980IBVS.1862....1E
- Naftilan, S. A.; Drake, S. A. (October 1980), "The spectrum of RS CVn.", Publications of the Astronomical Society of the Pacific, 92: 675–681, doi:10.1086/130728
- Pfeiffer, R. J. (August 1979), "Intrinsic linear polarization of the eclipsing binary RS Canum Venaticorum.", Astrophysical Journal, 232: 181–189, doi:10.1086/157277
- Rhombs, C. G.; Fix, J. D. (September 1977), "Spectrophotometry of RS Canum Venaticorum, AR Lacertae, and UX Arietis.", Astrophysical Journal, 216: 503–507, doi:10.1086/155491
- Rhombs, C. G.; Fix, J. D. (1976), "A spectrophotometric investigation of the wave of RS CVn.", Acta Astronautica, 26: 301–304, Bibcode:1976AcA....26..301R
- Oliver, J. P. (October 1975), "Comments on the tilted ring model for the eclipsing binary RS CVn", Publications of the Astronomical Society of the Pacific, 87: 695–697, doi:10.1086/129829
- Catalano, S.; Rodonò, M. (August 1974), "On the Orbital Period and Light Curve Variations of the Binary System RS Canum Venaticorum", Publications of the Astronomical Society of the Pacific, 86 (512): 390, doi:10.1086/129620
- Arnold, C. N.; Hall, D. S. (October 1973), "On the Period Variations in RS CVn and SS Cam", Information Bulletin on Variable Stars, 843: 1, Bibcode:1973IBVS..843....1A
- Hall, Douglas S. (April 1972), "A T Tauri-Like Star in the Eclipsing Binary RS Canum Venaticorum", Publications of the Astronomical Society of the Pacific, 84 (498): 323, S2CID 123585929
- Nelson, Burt; Duckworth, Edwin (October 1968), "Variations in the Light Curves of RS Canum Venticorum and SV Camelopardalis", Publications of the Astronomical Society of the Pacific, 80 (476): 562, doi:10.1086/128686
- Popper, Daniel M. (January 1961), "Rediscussion of Eclipsing Binaries. V. RS Canum Venaticorum", Astrophysical Journal, 133: 148, doi:10.1086/147011
- Plavec, M.; Smetanová, M. (1959), "Period variations of the eclipsing binary RS Canum Venaticorum", Bulletin of the Astronomical Institute of Czechoslovakia, 10: 192, Bibcode:1959BAICz..10..192P
- Keller, G.; Limber, D. N. (May 1951), "A Photoelectric Study of the Eclipsing Stars RS Canum Venaticorum and YY Sagittarii", Astrophysical Journal, 113: 637, doi:10.1086/145433
- Joy, A. H. (July 1930), "The spectrographic orbit of RS Canum Venaticorum", Astrophysical Journal, 72: 41–45, doi:10.1086/143258
- Schilt, J. (March 1927), "The short-period variable star RV Canum Venaticorum", Astrophysical Journal, 65: 124–129, doi:10.1086/143030
- Joy, A. H. (August 1922), "Spectroscopic Observations of R S Canum Venaticorum", Publications of the Astronomical Society of the Pacific, 34 (200): 221, doi:10.1086/123207
- Sitterly, B. W. (January 1921), "Provisional elements of the eclipsing system RS Canum Venaticorum", Astrophysical Journal, 53: 99–104, doi:10.1086/142586
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