Astronomy:HR 1099

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Short description: Triple star system in the constellation Taurus
HR 1099
Chart showing the position of the stars in the constellation Taurus
Red circle.svg
Location of HR 1099 (circled)
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| [[History:Epoch|Epoch J2000]]      [[Astronomy:Equinox (celestial coordinates)|Equinox J2000}}
Constellation Taurus
A
Right ascension  03h 36m 47.291s[1]
Declination 00° 35′ 15.94″[1]
Apparent magnitude (V) 5.91[2]
B
Right ascension  03h 36m 46.844s[3]
Declination 00° 35′ 15.93″[3]
Apparent magnitude (V) 8.79[2]
Characteristics
Spectral type K2:Vnk[4] (K1 IV + G5 V + K3 V)[5]
Variable type RS CVn[6]
Astrometry
A
Radial velocity (Rv)−21.24±6.62[1] km/s
Proper motion (μ) RA: −32.894[1] mas/yr
Dec.: −161.772[1] mas/yr
Parallax (π)33.7528 ± 0.0866[1] mas
Distance96.6 ± 0.2 ly
(29.63 ± 0.08 pc)
Absolute magnitude (MV)3.6[2]
B
Radial velocity (Rv)−15.34±0.18[3] km/s
Proper motion (μ) RA: −34.359 mas/yr
Dec.: −138.137 mas/yr
Parallax (π)33.8664 ± 0.0226[3] mas
Distance96.31 ± 0.06 ly
(29.53 ± 0.02 pc)
Absolute magnitude (MV)6.5[2]
Orbit[7]
Period (P)2.83774 d
Semi-major axis (a)10.3 R[8]
Eccentricity (e)0.00 (assumed)
Inclination (i)38[9]°
Periastron epoch (T)2,442,767.4 HJD
Argument of periastron (ω)
(secondary)
0.00 (assumed)°
Semi-amplitude (K1)
(primary)
52.6 km/s
Semi-amplitude (K2)
(secondary)
64.1 km/s
Details
Component Aa
Mass1.0[8] M
Radius3.7[8] R
Surface gravity (log g)3.30[5] cgs
Temperature4,750[5] K
Metallicity [Fe/H]−0.16[10] dex
Rotational velocity (v sin i)39[9] km/s
Component Ab
Mass0.8[8] M
Radius1.1[8] R
Surface gravity (log g)4.26[5] cgs
Temperature5,500[5] K
Component B
Mass0.78[11] M
Radius0.78[11] R
Luminosity0.30[11] L
Surface gravity (log g)4.55[11] cgs
Temperature4,829[11] K
Metallicity [Fe/H]+0.10[10] dex
Rotational velocity (v sin i)4.1[12] km/s
Age2.2[3] Gyr
Other designations
STF 422, V711 Tau, BD+00°616, GC 4311, HD 22468, HIP 16846, HR 1099, SAO 111291, PPM 146726, ADS 2644, WDS J03368+0035[13][14]
Database references
SIMBADdata

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]

A light curve for V711 Tauri, plotted from TESS data[19]

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

References

  1. 1.0 1.1 1.2 1.3 1.4 1.5 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 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, doi:10.1051/0004-6361/201732009, Bibcode2018A&A...614A.125F. 
  3. 3.0 3.1 3.2 3.3 3.4 Vallenari, A. et al. (2022). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy & Astrophysics. doi:10.1051/0004-6361/202243940  Gaia DR3 record for this source at VizieR.
  4. 4.0 4.1 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, doi:10.1086/504637, Bibcode2006AJ....132..161G. 
  5. 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8 5.9 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, doi:10.1051/0004-6361:20064847, Bibcode2006A&A...455..595L. 
  6. 6.0 6.1 Samus, N. N. et al. (2017), "General Catalogue of Variable Stars", Astronomy Reports, 5.1 61 (1): 80–88, doi:10.1134/S1063772917010085, Bibcode2017ARep...61...80S. 
  7. 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, Bibcode2000A&A...354..537S. 
  8. 8.0 8.1 8.2 8.3 8.4 Donati, J. -F. (January 1999), "Magnetic cycles of HR 1099 and LQ Hydrae", Monthly Notices of the Royal Astronomical Society 302 (3): 457–481, doi:10.1046/j.1365-8711.1999.02096.x, Bibcode1999MNRAS.302..457D. 
  9. 9.0 9.1 9.2 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, doi:10.1046/j.1365-2966.2003.07031.x, Bibcode2003MNRAS.345.1145D. 
  10. 10.0 10.1 Soubiran, Caroline et al. (2016), "The PASTEL catalogue: 2016 version", Astronomy & Astrophysics 591: A118, doi:10.1051/0004-6361/201628497, Bibcode2016A&A...591A.118S. 
  11. 11.0 11.1 11.2 11.3 11.4 Stassun K.G. (October 2019), "The revised TESS Input Catalog and Candidate Target List", The Astronomical Journal 158 (4): 138, doi:10.3847/1538-3881/ab3467, Bibcode2019AJ....158..138S. 
  12. Luck, R. Earle (January 2017), "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants", The Astronomical Journal 153 (1): 19, doi:10.3847/1538-3881/153/1/21, 21, Bibcode2017AJ....153...21L. 
  13. "HD 22468A". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+22468A. 
  14. "HD 22468B". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+22468B. 
  15. Sinnott, Roger W.; Perryman, Michael A. C. (1997), Millennium Star Atlas, 1, Sky Publishing Corporation and the European Space Agency, p. 260, ISBN 0-933346-84-0. 
  16. Mason, Brian D. et al. (2001), "The Washington Double Star Catalog", The Astronomical Journal 122 (6): 3466, doi:10.1086/323920, Bibcode2001AJ....122.3466M. 
  17. Wilson, O. C. (October 1963), "A Probable Correlation Between Chromospheric Activity and Age in Main-Sequence Stars", Astrophysical Journal 138: 832, doi:10.1086/147689, Bibcode1963ApJ...138..832W. 
  18. Wilson, O. C. (August 1964), "Chromospheric Activity and Lithium", Publications of the Astronomical Society of the Pacific 76 (451): 238, doi:10.1086/128091, Bibcode1964PASP...76..238W. 
  19. "MAST: Barbara A. Mikulski Archive for Space Telescopes". Space Telescope Science Institute. https://mast.stsci.edu/portal/Mashup/Clients/Mast/Portal.html. 
  20. 20.0 20.1 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, doi:10.1086/131208, Bibcode1983PASP...95..565V. 
  21. 21.0 21.1 Bopp, B. W.; Fekel, F., Jr. (September 1976), "HR 1099: a new bright RS CVn variable", Astronomical Journal 81: 771–774, doi:10.1086/111951, Bibcode1976AJ.....81..771B. 
  22. Owen, F. N. (March 1976), Marsden, B. G., ed., "HR 1099", IAU Circular 2929: 2, Bibcode1976IAUC.2929....2O. 
  23. Walter, F.; Charles, P.; Bowyer, S. (August 1978), "Discovery of quiescent X-ray emission from HR 1099, RS CVn", Nature 274 (5671): 569–570, doi:10.1038/274569b0, Bibcode1978Natur.274R.569W. 
  24. 24.0 24.1 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, doi:10.1111/j.1365-2966.2004.07420.x, Bibcode2004MNRAS.348.1175P. 
  25. Ramsey, L. W.; Nations, H. L. (August 1980), "HR 1099 and the starspot hypothesis for RS CVn binaries", Astrophysical Journal 239: L121–L124, doi:10.1086/183306, Bibcode1980ApJ...239L.121R. 
  26. 26.0 26.1 Berdyugina, Svetlana V.; Henry, Gregory W. (April 2007), "Butterfly Diagram and Activity Cycles in HR 1099", Astrophysical Journal 659 (2): L157–L160, doi:10.1086/517881, Bibcode2007ApJ...659L.157B. 

Further reading

  • Perdelwitz, V. et al. (August 2018), "Long-term variations in the X-ray activity of HR 1099", Astronomy & Astrophysics 616: A161, doi:10.1051/0004-6361/201732222, A161, Bibcode2018A&A...616A.161P. 
  • 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, doi:10.1086/420770, Bibcode2004ApJS..153..317O. 
  • 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, doi:10.1086/340300, Bibcode2002ApJ...572..487R. 
  • 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, doi:10.1086/319051, Bibcode2001ApJ...549..554A. 
  • 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, doi:10.1051/0004-6361:20000047, Bibcode2001A&A...365L.324B. 
  • 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, doi:10.1051/0004-6361:20000085, Bibcode2001A&A...365L.318A. 
  • 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, doi:10.1086/313195, Bibcode1997astro.ph..4191V. 
  • 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, doi:10.1093/mnras/260.4.903, Bibcode1993MNRAS.260..903T. 
  • Donati, J. -F. et al. (November 1992), "Photospheric imaging of the RS CVn system HR 1099.", Astronomy and Astrophysics 265: 682–700, Bibcode1992A&A...265..682D. 
  • Donati, J. -F. et al. (June 1990), "Detection of a magnetic region of HR 1099", Astronomy and Astrophysics 232: L1–L4, Bibcode1990A&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, Bibcode1987A&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, doi:10.1086/184296, Bibcode1984ApJ...282L..23L. 
  • Fekel, F. C., Jr. (May 1983), "Spectroscopy of V711 Tauri (= HR 1099) : fundamental properties and evidence for starspots", Astrophysical Journal 268: 274–281, doi:10.1086/160952, Bibcode1983ApJ...268..274F. 
  • Dorren, J. D. et al. (April 1981), "Starspots on V711 Tauri (HR 1099)", Astronomical Journal 86: 572–582, doi:10.1086/112918, Bibcode1981AJ.....86..572D. 
  • 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, doi:10.1086/112352, Bibcode1978AJ.....83.1504B. 
  • Feldman, P. A. et al. (December 1978), "Discovery of a strong radio flaring from HR 1099", Astronomical Journal 83: 1471–1484, doi:10.1086/112346, Bibcode1978AJ.....83.1471F. 
  • 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, doi:10.1086/112355, Bibcode1978AJ.....83.1517B. 
  • Gibson, D. M. et al. (December 1978), "VLA observations of HR 1099 during the 1977 international campaign", Astronomical Journal 83: 1495–1498, doi:10.1086/112350, Bibcode1978AJ.....83.1495G. 
  • Weiler, E. J. et al. (August 1980), "Coordinated ultraviolet, optical, and radio observations of HR 1099 and UX Arietis", Astrophysical Journal 239: L121–L124, doi:10.1086/183306, Bibcode1980ApJ...239L.121R. 
  • Owen, F. N. et al. (November 1976), "The detection of radio emission from the RS CVn binary HR 1099", Astrophysical Journal 210: L27–L30, doi:10.1086/182295, Bibcode1976ApJ...210L..27O.