HR 1099
HR 1099 is a triple star system in the equatorial constellation of Taurus, positioned 11′ to the north of the star 10 Tauri.[15] This system has the variable star designation V711 Tauri, while HR 1099 is the star's identifier from the Bright Star Catalogue. It ranges in brightness from a combined apparent visual magnitude of 5.71 down to 5.94,[6] which is bright enough to be dimly visible to the naked eye. The distance to this system is 96.6 light years based on parallax measurements,[1] but it is drifting closer with a radial velocity of about −15 km/s.
This system was discovered to be a double star by F. G. W. Struve in 1822, with the components A and B having an angular separation of 5.4″. (The separation was measured at 6.7″ in 2016.)[16] R. E. Wilson in 1953 determined that the brighter member of this pair, component A, has a variable radial velocity. In 1963, O. C. Wilson noted that the same component shows very high emission cores in the calcium H and K absorption lines.[17] Follow-up observations by O. C. Wilson in 1964 showed that the hydrogen–α line of component A is fully in emission and it displays moderate broadening due to rotation. He found a stellar classification of K3 V for component B, matching an ordinary K-type main-sequence star.[18]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/V711TauLightCurve.png/220px-V711TauLightCurve.png)
Observations during 1974–1975 demonstrated that component A is a spectroscopic binary star system of the RS Canum Venaticorum variable class. Given its average magnitude of around 5.9, it is one of the brighter known variables of this type.[20] No eclipses were observed, but an orbital period of 2.838 days was determined. Most of the emission was found to be coming from the more massive member of this pair.[21] Radio emission from the binary was detected by F. N. Owen in 1976.[22] It was shown to be a soft X-ray source in 1978 using the HEAO 1 satellite.[23]
This double-lined spectroscopic binary system consists of an evolving K-type subgiant and an ordinary G-type main sequence star. The two stars are orbiting so close to each other that their tidal effects are giving them an elliptical shape. The subgiant is filling about 80% of its Roche lobe.[5] The chromosphere of the subgiant is one of the most active known, with a deep convective zone powering the magnetic dynamo.[24][4] The G-type companion has a shallow convection zone and is less active.[5]
In 1980, significant variations were found in some spectral features related to surface temperature, suggesting the presence of starspots.[25] Doppler imaging confirmed these starspots are associated with the K subgiant. (It was the first cool star to have its surface Doppler imaged.[26]) The evidence suggests that the spots first appear at low latitude then migrated toward the poles.[20] These spots are much larger than they are on the Sun.[5] About 70% of all spots have been observed at latitudes higher than 50°, particularly around the polar region.[9][24] A polar spot has persisted for at least twenty years.[5]
The baseline apparent magnitudes of the two stars, after subtracting the effects of starspots, is 5.80 and 7.20.[5] Long term monitoring indicates the subgiant has two activity cycles, similar to the 11-year solar cycle. A 5.3±0.1 year cycle is associated with symmetrical flip-flopping of the spotted area between hemispheres. The longer 15–16 year cycle is a periodic variation in the total spot area. The global magnetic field of the star may be precessing with respect to the axis of rotation.[26]
See also
[edit]References
[edit]- ^ a b c d e f 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 d Freund, S.; Robrade, J.; Schneider, P. C.; Schmitt, J. H. M. M. (2018), "The stellar content of the XMM-Newton slew survey", Astronomy and Astrophysics, 614: A125, arXiv:1712.07410, Bibcode:2018A&A...614A.125F, doi:10.1051/0004-6361/201732009, S2CID 59396964.
- ^ a b c d e f 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 Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc—The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637, S2CID 119476992.
- ^ a b c d e f g h i j Lanza, A. F.; et al. (August 2006), "Long-term starspot evolution, activity cycle, and orbital period variation of V711 Tauri (HR 1099)", Astronomy and Astrophysics, 455 (2): 595–606, Bibcode:2006A&A...455..595L, doi:10.1051/0004-6361:20064847.
- ^ a b Samus, N. N.; et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1, 61 (1): 80–88, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
- ^ Strassmeier, K. G.; Bartus, J. (February 2000), "Doppler imaging of stellar surface structure. XII. Rapid spot changes on the RS CVn binary V711 Tauri = HR 1099", Astronomy and Astrophysics, 354: 537–550, Bibcode:2000A&A...354..537S.
- ^ a b c d e Donati, J. -F. (January 1999), "Magnetic cycles of HR 1099 and LQ Hydrae", Monthly Notices of the Royal Astronomical Society, 302 (3): 457–481, Bibcode:1999MNRAS.302..457D, doi:10.1046/j.1365-8711.1999.02096.x.
- ^ a b c Donati, J. -F.; et al. (November 2003), "Dynamo processes and activity cycles of the active stars AB Doradus, LQ Hydrae and HR 1099", Monthly Notices of the Royal Astronomical Society, 345 (4): 1145–1186, Bibcode:2003MNRAS.345.1145D, doi:10.1046/j.1365-2966.2003.07031.x.
- ^ a b Soubiran, Caroline; et al. (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.
- ^ a b c d e Stassun K.G.; et al. (October 2019), "The revised TESS Input Catalog and Candidate Target List", The Astronomical Journal, 158 (4): 138, arXiv:1905.10694, Bibcode:2019AJ....158..138S, doi:10.3847/1538-3881/ab3467, S2CID 166227927.
- ^ Luck, R. Earle (January 2017), "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants", The Astronomical Journal, 153 (1): 19, arXiv:1611.02897, Bibcode:2017AJ....153...21L, doi:10.3847/1538-3881/153/1/21, S2CID 119511744, 21.
- ^ "HD 22468A". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-04.
- ^ "HD 22468B". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2023-01-04.
- ^ Sinnott, Roger W.; Perryman, Michael A. C. (1997), Millennium Star Atlas, vol. 1, Sky Publishing Corporation and the European Space Agency, p. 260, ISBN 0-933346-84-0.
- ^ Mason, Brian D.; et al. (2001), "The Washington Double Star Catalog", The Astronomical Journal, 122 (6): 3466, Bibcode:2001AJ....122.3466M, doi:10.1086/323920.
- ^ Wilson, O. C. (October 1963), "A Probable Correlation Between Chromospheric Activity and Age in Main-Sequence Stars", Astrophysical Journal, 138: 832, Bibcode:1963ApJ...138..832W, doi:10.1086/147689.
- ^ Wilson, O. C. (August 1964), "Chromospheric Activity and Lithium", Publications of the Astronomical Society of the Pacific, 76 (451): 238, Bibcode:1964PASP...76..238W, doi:10.1086/128091, S2CID 111386087.
- ^ "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. Retrieved 22 January 2023.
- ^ a b Vogt, S. S.; Penrod, G. D. (September 1983), "Doppler imaging of spotted stars : application to the RS Canum Venaticorum star HR 1099", Publications of the Astronomical Society of the Pacific, 95: 565–576, Bibcode:1983PASP...95..565V, doi:10.1086/131208, S2CID 123206530.
- ^ a b Bopp, B. W.; Fekel, F. Jr. (September 1976), "HR 1099: a new bright RS CVn variable", Astronomical Journal, 81: 771–774, Bibcode:1976AJ.....81..771B, doi:10.1086/111951, hdl:2152/34302.
- ^ Owen, F. N. (March 1976), Marsden, B. G. (ed.), "HR 1099", IAU Circular, 2929: 2, Bibcode:1976IAUC.2929....2O.
- ^ Walter, F.; Charles, P.; Bowyer, S. (August 1978), "Discovery of quiescent X-ray emission from HR 1099, RS CVn", Nature, 274 (5671): 569–570, Bibcode:1978Natur.274R.569W, doi:10.1038/274569b0, S2CID 4206226.
- ^ a b Petit, P.; et al. (March 2004), "Magnetic topology and surface differential rotation on the K1 subgiant of the RS CVn system HR 1099", Monthly Notices of the Royal Astronomical Society, 348 (4): 1175–1190, arXiv:astro-ph/0312238, Bibcode:2004MNRAS.348.1175P, doi:10.1111/j.1365-2966.2004.07420.x, S2CID 119463091.
- ^ Ramsey, L. W.; Nations, H. L. (August 1980), "HR 1099 and the starspot hypothesis for RS CVn binaries", Astrophysical Journal, 239: L121–L124, Bibcode:1980ApJ...239L.121R, doi:10.1086/183306.
- ^ a b Berdyugina, Svetlana V.; Henry, Gregory W. (April 2007), "Butterfly Diagram and Activity Cycles in HR 1099", Astrophysical Journal, 659 (2): L157–L160, arXiv:astro-ph/0703530, Bibcode:2007ApJ...659L.157B, doi:10.1086/517881, S2CID 14242208.
Further reading
[edit]- Perdelwitz, V.; et al. (August 2018), "Long-term variations in the X-ray activity of HR 1099", Astronomy & Astrophysics, 616: A161, arXiv:1806.03033, Bibcode:2018A&A...616A.161P, doi:10.1051/0004-6361/201732222, S2CID 55130058, A161.
- Osten, Rachel A.; et al. (July 2004), "A Multiwavelength Perspective of Flares on HR 1099: 4 Years of Coordinated Campaigns", Astrophysical Journal Supplement Series, 153 (1): 317–362, arXiv:astro-ph/0402613, Bibcode:2004ApJS..153..317O, doi:10.1086/420770, S2CID 119522693.
- Ransom, R. R.; et al. (June 2002), "Possible Corotation of the Milliarcsecond Radio Structure of the Close Binary HR 1099", Astrophysical Journal, 572 (1): 487–502, Bibcode:2002ApJ...572..487R, doi:10.1086/340300, S2CID 120225374.
- Ayres, Thomas R.; et al. (March 2001), "Chandra, EUVE, HST, and VLA Multiwavelength Campaign on HR 1099: Instrumental Capabilities, Data Reduction, and Initial Results", Astrophysical Journal, 549 (1): 554–577, Bibcode:2001ApJ...549..554A, doi:10.1086/319051, S2CID 15938906.
- Brinkman, A. C.; et al. (January 2001), "First light measurements with the XMM-Newton reflection grating spectrometers: Evidence for an inverse first ionisation potential effect and anomalous Ne abundance in the Coronae of HR 1099", Astronomy and Astrophysics, 365: L324–L328, arXiv:astro-ph/0011018, Bibcode:2001A&A...365L.324B, doi:10.1051/0004-6361:20000047, S2CID 15848464.
- Audard, M.; et al. (January 2001), "The XMM-Newton view of stellar coronae: Flare heating in the coronae of HR 1099", Astronomy and Astrophysics, 365: L318–L323, Bibcode:2001A&A...365L.318A, doi:10.1051/0004-6361:20000085.
- Vogt, Steven S.; et al. (April 1997), "Doppler Imagery of the Spotted RS CVn Star HR 1099 (= V711 Tau) from 1981 - 1992", Astrophysical Journal Supplement Series, 121: 547, arXiv:astro-ph/9704191, Bibcode:1997astro.ph..4191V, doi:10.1086/313195, S2CID 119515171.
- Trigilio, C.; et al. (February 1993), "VLBI observations of a strong radio flare in HR 1099", Monthly Notices of the Royal Astronomical Society, 260 (4): 903–907, Bibcode:1993MNRAS.260..903T, doi:10.1093/mnras/260.4.903.
- Donati, J. -F.; et al. (November 1992), "Photospheric imaging of the RS CVn system HR 1099.", Astronomy and Astrophysics, 265: 682–700, Bibcode:1992A&A...265..682D.
- Donati, J. -F.; et al. (June 1990), "Detection of a magnetic region of HR 1099", Astronomy and Astrophysics, 232: L1–L4, Bibcode:1990A&A...232L...1D.
- Rodono, M.; et al. (April 1987), "Rotational modulation and flares on RS CVn and BY DRA stars. III. IUEobserations of V711 Tau = (HR 1099), II Peg and AR Lac", Astronomy and Astrophysics, 176: 267–284, Bibcode:1987A&A...176..267R.
- Lestrade, J. F.; et al. (July 1984), "Detection of a sub-milliarcsecond radio component in the RS CVn system HR 1099", Astrophysical Journal, 282: L23–L26, Bibcode:1984ApJ...282L..23L, doi:10.1086/184296.
- Fekel, F. C. Jr. (May 1983), "Spectroscopy of V711 Tauri (= HR 1099) : fundamental properties and evidence for starspots", Astrophysical Journal, 268: 274–281, Bibcode:1983ApJ...268..274F, doi:10.1086/160952.
- Dorren, J. D.; et al. (April 1981), "Starspots on V711 Tauri (HR 1099)", Astronomical Journal, 86: 572–582, Bibcode:1981AJ.....86..572D, doi:10.1086/112918.
- Brown, R. L.; Crane, P. C. (December 1978), "On the rapidly variable circular polarization of HR 1099 at radio frequencies", Astronomical Journal, 83: 1504–1509, Bibcode:1978AJ.....83.1504B, doi:10.1086/112352.
- Feldman, P. A.; et al. (December 1978), "Discovery of a strong radio flaring from HR 1099", Astronomical Journal, 83: 1471–1484, Bibcode:1978AJ.....83.1471F, doi:10.1086/112346.
- Bopp, B. W.; Talcott, J. C. (December 1978), "Survey of Halpha emission in V711 Tau (HR 1099) and related Ca II emission binaries", Astronomical Journal, 83: 1517–1521, Bibcode:1978AJ.....83.1517B, doi:10.1086/112355.
- Gibson, D. M.; et al. (December 1978), "VLA observations of HR 1099 during the 1977 international campaign", Astronomical Journal, 83: 1495–1498, Bibcode:1978AJ.....83.1495G, doi:10.1086/112350.
- Weiler, E. J.; et al. (August 1980), "Coordinated ultraviolet, optical, and radio observations of HR 1099 and UX Arietis", Astrophysical Journal, 239: L121–L124, Bibcode:1980ApJ...239L.121R, doi:10.1086/183306.
- Owen, F. N.; et al. (November 1976), "The detection of radio emission from the RS CVn binary HR 1099", Astrophysical Journal, 210: L27–L30, Bibcode:1976ApJ...210L..27O, doi:10.1086/182295.