SZ Piscium

SZ Piscium

A visual band light curve for SZ Piscium, adapted from Eaton et al. (1982)[1]
Observation data
Epoch J2000.0      Equinox J2000.0
Constellation Pisces
Right ascension 23h 13m 23.778s[2]
Declination 02° 40′ 31.60″[2]
Apparent magnitude (V) 7.18[3]
Characteristics
Spectral type K1IV + F8V + ?[4]
Variable type EA/DS/RS[3]
Astrometry
Radial velocity (Rv)12.00±2[5] km/s
Proper motion (μ) RA: 23.624 mas/yr[2]
Dec.: 26.346 mas/yr[2]
Parallax (π)10.6705 ± 0.1864 mas[2]
Distance306 ± 5 ly
(94 ± 2 pc)
Orbit[4]
PrimaryK star
CompanionF star
Period (P)3.96566356 d
Semi-major axis (a)15.2 R☉[6]
Eccentricity (e)0 (fixed)
Inclination (i)69.75°
Semi-amplitude (K1)
(primary)		74.2 km/s
Semi-amplitude (K2)
(secondary)		103.98 km/s
Orbit[7]
PrimaryInner binary
CompanionThird star
Period (P)1,530±3 d
Eccentricity (e)0.325±0.013
Periastron epoch (T)2,452,235±13 HJD
Argument of periastron (ω)
(secondary)		3.0±1.7°
Semi-amplitude (K1)
(primary)		6.2±0.3 km/s
Semi-amplitude (K2)
(secondary)		25.3±0.8 km/s
Details
K star
Mass1.74[6] M☉
Radius6.0[6] R☉
Luminosity12.3[6] L☉
Temperature4,910[4] K
Rotational velocity (v sin i)3.0±0.6[4] km/s
F star
Mass1.33[6] M☉
Radius1.52[6] R☉
Luminosity3.98[6] L☉
Temperature6,090[4] K
Rotational velocity (v sin i)67.7±1.0[4] km/s
Other designations
SZ Psc, AG+02 2918, BD+01 4695, HD 219113, HIP 114639, SAO 128041, PPM 173881, WDS 23134+0241[8]
Database references
SIMBADdata

SZ Piscium is a triple star[7] system in the equatorial constellation of Pisces. The inner pair form a double-lined spectroscopic binary with an orbital period of 3.966 days.[9] It is a detached Algol-type eclipsing binary of the RS Canum Venaticorum class with a subgiant component. (This means the pair have a close but separated orbit with the stars eclipsing one another, and the primary component is an evolving star showing star spots and other magnetic activity.) The system is too faint to be readily visible to the naked eye with a combined apparent visual magnitude of 7.18.[3] It is located at a distance of approximately 306 light years based on parallax measurements.[2]

The variability of this star was reported by A. Jensch in 1934, who published the first elements.[10] In 1956 the spectrum of the system was examined by N. G. Roman, who found the cooler component is the brighter and more evolved.[11] The system was studied by G. A. Bakos and J. F. Heard in 1958, who found a magnitude of 7.72 for the primary eclipse minimum and 7.30 for the secondary. They refined the class estimates, finding the primary is probably a K1IV subgiant in close orbit with an F8V main sequence star.[12] In 1972, H. L. Atkins and D. S. Hall included it on a list of RS Canum Venaticorum type variable systems and showed it has an infrared excess.[13]

S. Jakate and associates in 1976 found that the period of luminosity variation is changing over time. They discovered strong emission in the H and K lines of the K star and noted that it showed intrinsic variability.[9] The system displayed unusual episodes of emission and variation in the Hα line, which was interpreted by astronomers as ejected material possibly forming a transient disk.[14] The orbital period of the system varies in a 56 year cycle with an amplitude of 4.3×10−4 d, which may be explained by influences of the stellar wind and magnetic activity.[4]

Significant star spot activity was found all over the K-type star, with variations in the total spot coverage observed over time.[6] It is estimated to be filling 85% of its Roche lobe due to the gravitational influence of the secondary. The rotation period of this star is several times slower than its orbital period, while the rotation of the F-type star is synchronous.[4] Changes in radial velocity of the system over time suggest it is a triple star system with the tertiary component having about 75% of the mass of the Sun and an orbital period of 1,530±3 days.[7]

References

  1. ^ Eaton, J. A.; Scaltriti, F.; Cerruti-Sola, M.; Sarma, M. B. K.; Ausekar, B. D.; Catalano, S.; Rodono, M. (March 1982). "Light curves of SZ Piscium for 1977 and 1978". Astrophysics and Space Science. 82 (2): 289–306. Bibcode:1982Ap&SS..82..289E. doi:10.1007/BF00651440. S2CID 120020249. Retrieved 24 June 2022.
  2. ^ a b c d e Brown, A. G. A.; et al. (Gaia collaboration) (2021). "Gaia Early Data Release 3: Summary of the contents and survey properties". Astronomy & Astrophysics. 649: A1. arXiv:2012.01533. Bibcode:2021A&A...649A...1G. doi:10.1051/0004-6361/202039657. S2CID 227254300. (Erratum: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  3. ^ a b c Samus', N. N; et al. (2017), "General catalogue of variable stars", Astronomy Reports, GCVS 5.1, 61 (1): 80, Bibcode:2017ARep...61...80S, doi:10.1134/S1063772917010085, S2CID 125853869.
  4. ^ a b c d e f g h Xiang, Yue; et al. (February 2016), "The first Doppler images of the eclipsing binary SZ Piscium", Monthly Notices of the Royal Astronomical Society, 456 (1): 314–322, arXiv:1511.02875, Bibcode:2016MNRAS.456..314X, doi:10.1093/mnras/stv2642.
  5. ^ Karataș, Yüksel; et al. (2004), "Kinematics of chromospherically active binaries and evidence of an orbital period decrease in binary evolution", Monthly Notices of the Royal Astronomical Society, 349 (3): 1069–1092, arXiv:astro-ph/0404219, Bibcode:2004MNRAS.349.1069K, doi:10.1111/j.1365-2966.2004.07588.x, S2CID 15290475.
  6. ^ a b c d e f g h Eaton, Joel A.; Henry, Gregory W. (March 2007), "The Distribution of Activity on the RS CVn-Type Star SZ Piscium", The Publications of the Astronomical Society of the Pacific, 119 (853): 259–273, Bibcode:2007PASP..119..259E, doi:10.1086/516603, S2CID 14758154.
  7. ^ a b c Xiang, Yue; et al. (2024), "Further Study of Starspot Activity and Measurement of Differential Rotation for SZ Piscium", The Astrophysical Journal, 976 (2): 217, arXiv:2410.17497, Bibcode:2024ApJ...976..217X, doi:10.3847/1538-4357/ad86bd.
  8. ^ "SZ Psc", SIMBAD, Centre de données astronomiques de Strasbourg, retrieved 2022-03-21.
  9. ^ a b Jakate, S.; et al. (April 1976), "Eclipsing binary system SZ Piscium", Astronomical Journal, 81: 250–256, Bibcode:1976AJ.....81..250J, doi:10.1086/111880.
  10. ^ Kang, Young Woon; et al. (October 2003), "Chromospheric activity and unique solution of SZ Psc", Monthly Notices of the Royal Astronomical Society, 344 (4): 1227–1232, Bibcode:2003MNRAS.344.1227K, doi:10.1046/j.1365-8711.2003.06909.x, S2CID 120782775.
  11. ^ Roman, Nancy G. (March 1956), "Spectral Types of Some Eclipsing Binaries", Astrophysical Journal, 123: 246, Bibcode:1956ApJ...123..246R, doi:10.1086/146155.
  12. ^ Bakos, G. A.; Heard, J. F. (February 1958), "The eclipsing system, SZ Psc", Astronomical Journal, 63: 302, Bibcode:1958AJ.....63Q.302B, doi:10.1086/107661.
  13. ^ Atkins, H. L.; Hall, D. S. (October 1972), "Infrared excesses in eclipsing binaries of the RS Canum Venaticorum type", Publications of the Astronomical Society of the Pacific, 84: 638, Bibcode:1972PASP...84..638A, doi:10.1086/129349, S2CID 121175598.
  14. ^ Ramsey, L. W.; Nations, H. L. (December 1981), "On the nature of H alf outbursts in the RS CVn binary SZ Psc", Publications of the Astronomical Society of the Pacific, 93: 732–734, Bibcode:1981PASP...93..732R, doi:10.1086/130917, S2CID 120698419.

Further reading

  • Cao, Dongtao; et al. (June 2020), "Further Investigation on Chromospheric and Prominence Activity of the RS Canum Venaticorum Star SZ Piscium", The Astronomical Journal, 159 (6): 15, Bibcode:2020AJ....159..292C, doi:10.3847/1538-3881/ab8f90, S2CID 219969221, 292.
  • Cao, Dongtao; et al. (January 2019), "Prominence activation, optical flare, and post-flare loops on the RS Canum Venaticorum star SZ Piscium", Monthly Notices of the Royal Astronomical Society, 482 (1): 988–998, arXiv:2401.02590, Bibcode:2019MNRAS.482..988C, doi:10.1093/mnras/sty2768.
  • Drake, S. A.; et al. (2015), "The Swift Detection of a Large Flare from the RS CVn Binary SZ Psc", GRB Coordinates Network, Circular Service, vol. 17304, no. 1, p. 1, Bibcode:2015GCN.17304....1D.
  • Cao, Dong-Tao; Gu, Sheng-Hong (February 2012), "New observations of chromospheric and prominence activity on the RS CVn-type binary SZ Piscium", Astronomy & Astrophysics, 538: 4, Bibcode:2012A&A...538A.130C, doi:10.1051/0004-6361/201118184, S2CID 119931636, A130.
  • Negoro, H.; et al. (November 2011), "MAXI/GSC detection of a possible flare from the RS CVn type star SZ Psc", The Astronomer's Telegram, 3737: 1, Bibcode:2011ATel.3737....1N.
  • Wang, Xiao-Liang; et al. (June 2010), "Orbital Period Change of the Eclipsing Binary System SZ Piscium", Publications of the Astronomical Society of Japan, 62 (3): 671–674, Bibcode:2010PASJ...62..671W, doi:10.1093/pasj/62.3.671.
  • Zhang, L. -Y.; Gu, S. -H. (August 2008), "Chromospheric activity on the RS Canum Venaticorum binary SZ Piscium", Astronomy and Astrophysics, 487 (2): 709–716, Bibcode:2008A&A...487..709Z, doi:10.1051/0004-6361:200809688.
  • Lanza, A. F.; et al. (September 2001), "Long-term starspot evolution, activity cycle and orbital period variation of SZ Piscium", Astronomy and Astrophysics, 376 (3): 1011–1030, Bibcode:2001A&A...376.1011L, doi:10.1051/0004-6361:20011038.
  • Antonopoulou, E.; et al. (November 1995), "Photoelectric Observations of SZ Psc During 1993-1994", Information Bulletin on Variable Stars, 4262 (1): 1, Bibcode:1995IBVS.4262....1A.
  • Kalimeris, A.; et al. (January 1995), "An orbital period study of SZ Piscium", Astronomy and Astrophysics, 293: 371–376, Bibcode:1995A&A...293..371K.
  • Doyle, J. G.; et al. (November 1994), "Surface inhomogeneities on SZ Piscium", Astronomy and Astrophysics, 291: 135–142, Bibcode:1994A&A...291..135D.
  • Doyle, J. G.; et al. (March 1994), "Ultraviolet flare activity on the eclipsing binary SZ Piscium", Astronomy and Astrophysics, 283: 522–524, Bibcode:1994A&A...283..522D.
  • Danezis, E.; et al. (January 1992), "The Ultraviolet Spectrum of the Binary System Sz-Piscium", Astrophysics and Space Science, 187 (2): 307–318, Bibcode:1992Ap&SS.187..307D, doi:10.1007/BF00643397, S2CID 189850636.
  • Thompson, K. (December 1987), "Photometric Observations on SZ Psc", Information Bulletin on Variable Stars, 3119 (1): 1, Bibcode:1987IBVS.3119....1T.
  • Bakos, Gustav; Tremko, Josef (November 1987), "The Light Curve Analysis of SZ PISCIUM", Bulletin of the Astronomical Institute of Czechoslovakia, 38: 356, Bibcode:1987BAICz..38..356B.
  • Scaltriti, F.; et al. (December 1985), "Some Comments on the Minima of the RS CVn Type Eclipsing Binaries CQ Aur, RU Cnc, VV Mon and SZ Psc", Information Bulletin on Variable Stars, 2841 (1): 1, Bibcode:1985IBVS.2841....1S.
  • Percy, J. R. (June 1985), "A note on two RS Canum Venaticorum stars : LX Persei and SZ Piscium", Journal of the Royal Astronomical Society of Canada, 79: 113–118, Bibcode:1985JRASC..79..113P.
  • Antonopoulou, E.; Williams, P. M. (June 1984), "Infrared photometry of the RS CVn binaries. IV. SZ Piscium", Astronomy and Astrophysics, 135: 61–65, Bibcode:1984A&A...135...61A.
  • Huenemoerder, D. P.; Ramsey, L. W. (April 1984), "Hydrogen-alpha observations of RS Canum Venaticorum stars. III. The eclipsing systems AR Lacertae and SZ Piscium", Astronomical Journal, 89: 549–558, Bibcode:1984AJ.....89..549H, doi:10.1086/113547.
  • Tumer, O.; et al. (February 1980), "B V Light Curves of SZ Psc", Information Bulletin on Variable Stars, 1741 (1): 1, Bibcode:1980IBVS.1741....1T.
  • Okazaki, Akira (February 1979), "Photoelectric Observations of SZ Piscium", Information Bulletin on Variable Stars, 1560 (1): 1, Bibcode:1979IBVS.1560....1O.
  • Catalano, S.; et al. (May 1978), "The Orbital Period Variation of SZ Psc", Information Bulletin on Variable Stars, 1427 (1): 1, Bibcode:1978IBVS.1427....1C.
  • Eaton, J. A. (July 1977), "Further Light Curve Variations of SZ Piscium", Information Bulletin on Variable Stars, 1297 (1): 1, Bibcode:1977IBVS.1297....1E.
  • Jensch, A. (August 1934), "Ergebnisse photographischer und visueller Beobachtungen an 7 Veräderlichen", Astronomische Nachrichten, 252 (24): 393, Bibcode:1934AN....252..393J, doi:10.1002/asna.19342522403. As '35.1934 Piscium'.