Skip to content
DraconiticResearch
Search Sources API
194,230 studies31 sourcesUpdated 56 min ago
Peer-reviewedCC BY 4.0Monthly Notices of the Royal Astronomical Society

Accretion geometry and variability in QS Telescopii from multi-epoch observations

  • L Booi1,2
  • S B Potter2,3
  • Z N Khangale1,2
  • V Moloi1,2
  • P A Woudt1
  1. 1Department of Astronomy, University of Cape Town , Private Bag X1, Rondebosch 7701 ,
  2. 2South African Astronomical Observatory, Observatory Road , Observatory, 7925 Cape Town ,
  3. 3Department of Physics, University of Johannesburg , PO Box 524, Auckland Park 2006 ,
Open at sourcePDFDOICite

Abstract

We present phase-resolved photometry, spectroscopy, photopolarimetry, and circular spectropolarimetry of the polar QS Telescopii, obtained between 2017 and 2025 using the South African Astronomical Observatory (SAAO) 1.0-m and 1.9-m telescopes, the Transiting Exoplanet Survey Satellite (TESS), Asteroid Terrestrial-impact Last Alert System (ATLAS), and the Southern African Large Telescope (SALT). From ground-based photometry, we report the first detection of quasi-periodic oscillations (QPOs) in QS Tel, with time-scales ranging between 2 and 11 min. This makes QS Tel one of only seven polars to show QPOs. The average spectra of QS Tel show broad and strong Balmer (Hδ, Hγ, Hβ, and Hα) and He ii 4686 Å emission lines, along with weaker emission from He i at (6678, 5017, 4921, 4712, 4471, and 4387 Å) and the Bowen fluorescence complex C iii/N iii at 4650 Å. For the first time detailed Doppler tomography of the Hα and He ii 4686 Å lines are presented which reveal emission from the irradiated face of the secondary star, the ballistic stream, the threading region, and complex magnetically confined flows. The magnetically confined accretion stream splits into two distinct components coming from the same stream. One component appears near the threading region and the other component is seen along the high velocity in the magnetically confined accretion stream closer to the white dwarf. Broad-band photopolarimetry reveals circular polarization reaching levels of +8 per cent, however more detailed circular spectropolarimetry shows polarization ranging from −10 per cent to +25 per cent, associated with two broad, phase-dependent cyclotron humps centred at ∼4800 and ∼6300 Å, consistent with a magnetic field strength of ∼53 MG.

Related

  1. Multi-scale variability in the optical afterglow of GRB 251013C from high-cadence LAST observations
    R. Konno, E. O. Ofek, S. Garrappa +8
    arXivPreprintarXiv licenceFull textHigh-energy astrophysicsarXiv
  2. BlackHoleWeather – Spin-coupled chaotic cold accretion across the meso scale: Kinematics and variability
    Olmo Piana, Massimo Gaspari, Vieri Cammelli +10
    Astronomy & AstrophysicsPeer-reviewedPublisher termsSolar & stellar physicsCrossref
  3. XMM-Newton observations of the highest field polar AR UMa. An extreme case of soft-blobby accretion
    K.G. Pradeep, A.D. Schwope
    Astronomy & AstrophysicsPeer-reviewedPublisher termsSolar & stellar physicsCrossref
  4. 3D simulations of magnetospheric accretion in T Tauri stars I. Disk truncation, stellar torques, and application to observations
    G. Pantolmos, C. Zanni, J. Bouvier
    Astronomy & AstrophysicsPeer-reviewedPublisher termsSolar & stellar physicsCrossref
  5. Impact of accretion variability on the CO emission of a disk around a very low-mass star with JWST
    C. Bergez-Casalou, B. Tabone, Y. Aoyama +14
    Astronomy & AstrophysicsPeer-reviewedPublisher termsSolar & stellar physicsCrossref

Cite

BibTeXRIS
BibTeX
@article{booi2026accretion,
  title = {{Accretion geometry and variability in QS Telescopii from multi-epoch observations}},
  author = {L Booi and S B Potter and Z N Khangale and V Moloi and P A Woudt},
  journal = {Monthly Notices of the Royal Astronomical Society},
  year = {2026},
  month = oct,
  doi = {10.1093/mnras/stag1877},
  url = {https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1877/8869236},
  note = {CC BY 4.0},
}
RIS
TY  - JOUR
TI  - Accretion geometry and variability in QS Telescopii from multi-epoch observations
AU  - L Booi
AU  - S B Potter
AU  - Z N Khangale
AU  - V Moloi
AU  - P A Woudt
PY  - 2026
DA  - 2026/10/06
JO  - Monthly Notices of the Royal Astronomical Society
DO  - 10.1093/mnras/stag1877
UR  - https://academic.oup.com/mnras/article/doi/10.1093/mnras/stag1877/8869236
AB  - We present phase-resolved photometry, spectroscopy, photopolarimetry, and circular spectropolarimetry of the polar QS Telescopii, obtained between 2017 and 2025 using the South African Astronomical Observatory (SAAO) 1.0-m and 1.9-m telescopes, the Transiting Exoplanet Survey Satellite (TESS), Asteroid Terrestrial-impact Last Alert System (ATLAS), and the Southern African Large Telescope (SALT). From ground-based photometry, we report the first detection of quasi-periodic oscillations (QPOs) in QS Tel, with time-scales ranging between 2 and 11 min. This makes QS Tel one of only seven polars to show QPOs. The average spectra of QS Tel show broad and strong Balmer (Hδ, Hγ, Hβ, and Hα) and He ii 4686 Å emission lines, along with weaker emission from He i at (6678, 5017, 4921, 4712, 4471, and 4387 Å) and the Bowen fluorescence complex C iii/N iii at 4650 Å. For the first time detailed Doppler tomography of the Hα and He ii 4686 Å lines are presented which reveal emission from the irradiated face of the secondary star, the ballistic stream, the threading region, and complex magnetically confined flows. The magnetically confined accretion stream splits into two distinct components coming from the same stream. One component appears near the threading region and the other component is seen along the high velocity in the magnetically confined accretion stream closer to the white dwarf. Broad-band photopolarimetry reveals circular polarization reaching levels of +8 per cent, however more detailed circular spectropolarimetry shows polarization ranging from −10 per cent to +25 per cent, associated with two broad, phase-dependent cyclotron humps centred at ∼4800 and ∼6300 Å, consistent with a magnetic field strength of ∼53 MG.
SN  - 0035-8711
SN  - 1365-2966
ER  -