QS Telescopii

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QS Telescopii
QSTelLightCurve.png
A visual band light curve for QS Telescopii, adapted from Rosen et al. (1996) [1]
Observation data
Epoch J2000.0        Equinox J2000.0
Constellation Telescopium
Right ascension 19h 38m 35.816s [2]
Declination −46° 12 57.11 [2]
Characteristics
Spectral type M4.5±0.5 [3]
Variable type AM Her [4]
Astrometry
Radial velocity (Rv)110 km/s
Proper motion (μ)RA: +35.150 mas/yr [2]
Dec.: −25.496 mas/yr [2]
Parallax (π)5.3378±0.0834  mas [2]
Distance 611 ± 10  ly
(187 ± 3  pc)
Orbit [5]
Period (P)2.33 h
Eccentricity (e)0.0
Details
White Dwarf
Mass 0.71 [6]   M
Temperature 17,500 [6]   K
Other designations
QS Tel, EUVE J1938-46.2, RE 1938-461, AAVSO 1931-46 [7]
Database references
SIMBAD data

QS Telescopii is a faint, well-studied [4] binary star system in the southern constellation Telescopium. [7] It is composed of a white dwarf and main sequence donor star, locked into a close, circular orbit facing one another. Known as polars, material from the donor star does not form an accretion disk around the white dwarf, but rather streams directly onto it. [6] This is due to the presence of the white dwarf's strong magnetic field. The pair undergo frequent shifts between a high and low accretion states, and it shifts between single and double accretion poles. The main pole is partially self-eclipsing. [4]

Contents

In 1991, David A. H. Buckley et al. discovered that the object (then called RE 1938-461) is a variable star. [8] It was given its variable star designation, QS Telescopii, in 1995. [9] The pair of stars orbit each other with a period of 2.33 [5]  hours in a circular orbit. The donor star is a small red dwarf with an estimated stellar classification of M4−5. [3] The white dwarf primary has 71% of the mass of the Sun and an effective temperature of 17,500 K. [6] It has a magnetic field strength of 50–80  MG. The system is a source for X-ray emission. [4]

See also

References

  1. Rosen, S. R.; Mittaz, J. P. D.; Buckley, D. A.; Layden, A. C.; Clayton, K. L.; McCain, C.; Wynn, G. A.; Sirk, M. M.; Osborne, J. P.; Watson, M. G. (June 1996). "Accretion mode changes in QS Tel (RE 1938 — 461): EUVE, ROSAT and optical observations". Monthly Notices of the Royal Astronomical Society. 280 (4): 1121–1142. Bibcode:1996MNRAS.280.1121R. doi: 10.1093/mnras/280.4.1121 . hdl: 2381/38963 .
  2. 1 2 3 4 5 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.
  3. 1 2 Knigge, Christian (December 2006). "The donor stars of cataclysmic variables". Monthly Notices of the Royal Astronomical Society. 373 (2): 484–502. arXiv: astro-ph/0609671 . Bibcode:2006MNRAS.373..484K. doi: 10.1111/j.1365-2966.2006.11096.x . S2CID   2616606.
  4. 1 2 3 4 Traulsen, I.; Reinsch, K.; Schwope, A. D.; Burwitz, V.; et al. (2011). "XMM-Newton observations of the X-ray soft polar QS Telescopii". Astronomy and Astrophysics. 529 (A116): 7. arXiv: 1103.4575 . Bibcode:2011A&A...529A.116T. doi:10.1051/0004-6361/201016352. S2CID   119187792.
  5. 1 2 Augusteijn, T.; et al. (June 2010). "Cataclysmic variables from the Calán-Tololo Survey - II. Spectroscopic periods". Monthly Notices of the Royal Astronomical Society. 405 (1): 621–637. Bibcode:2010MNRAS.405..621A. doi: 10.1111/j.1365-2966.2010.16487.x . hdl: 10533/144049 .
  6. 1 2 3 4 Gerke, Jill R.; et al. (2006). "Polars Changing State: Multiwavelength Long-Term Photometry and Spectroscopy of QS Telescopii, V834 Centauri, and BL Hydri". Publications of the Astronomical Society of the Pacific. 118 (843): 678–86. arXiv: astro-ph/0603097 . Bibcode:2006PASP..118..678G. doi:10.1086/503753. S2CID   14857705.
  7. 1 2 "QS Tel". SIMBAD . Centre de données astronomiques de Strasbourg . Retrieved 2021-11-25.
  8. Buckley, D. A.; O'Donoghue, D.; Hassall, B. J. M.; Kellett, B. J.; Mason, K. O.; Sekiguchi, K.; Watson, M. G.; Wheatley, P. J.; Chen, A. (May 1993). "Discovery of an EUV-bright polar in the period gap from the ROSAT Wide Field Camera sky survey". Monthly Notices of the Royal Astronomical Society. 262: 93–108. Bibcode:1993MNRAS.262...93B. doi: 10.1093/mnras/262.1.93 . Retrieved 30 August 2025.
  9. Kazarovets, E. V.; Samus, N. N. (January 1995). "The 72nd Name-List of Variable Stars" (PDF). Information Bulletin on Variable Stars. 4140: 1. Bibcode:1995IBVS.4140....1K . Retrieved 30 August 2025.

Further reading