Pelisoli, I., Marsh, T.R., Dhillon, V.S. et al. (9 more authors) (Submitted: 2021) Found : a rapidly spinning white dwarf in LAMOST J024048.51+195226.9. arXiv. (Submitted)
Abstract
We present optical photometry of the cataclysmic variable LAMOST J024048.51+195226.9 taken with the high-speed, five-band CCD camera HiPERCAM on the 10.4 m Gran Telescopio Canarias (GTC). We detect pulsations originating from the spin of its white dwarf, finding a spin period of 24.9328(38)s. The pulse amplitude is of the order of 0.2% in the g-band, below the detection limits of previous searches. This detection establishes LAMOST J024048.51+195226.9 as only the second white dwarf magnetic propeller system, a twin of its long-known predecessor, AE Aquarii. At 24.93s, the white dwarf in LAMOST J024048.51+195226.9 has the shortest known spin period of any cataclysmic variable star. The white dwarf must have a mass of at least 0.7MSun to sustain so short a period. The observed faintest u-band magnitude sets an upper limit on the white dwarf's temperature of ~25000K. The pulsation amplitudes measured in the five HiPERCAM filters are consistent with an accretion spot of ~30000K covering ~2% of the white dwarf's visible area, although much hotter and smaller spots cannot be ruled out.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2021 The Authors. |
Keywords: | binaries: general; stars: cataclysmic variables; binaries: close |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > Department of Physics and Astronomy (Sheffield) |
Funding Information: | Funder Grant number Science and Technology Facilities Council ST/R003424/1 Engineering and Physical Sciences Research Council 2263443 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 10 Sep 2021 07:19 |
Last Modified: | 23 Jan 2023 17:13 |
Status: | Submitted |
Identification Number: | 10.48550/arXiv.2108.11396 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:177952 |