Periodicities in the K2 light curve of HP Librae

Solanki, Siddhant; Kupfer, Thomas; Blaes, Omer; Breedt, Elmé; Scaringi, Simone

doi:10.1093/mnras/staa3240

Periodicities in the K2 light curve of HP Librae

Solanki, Siddhant; Kupfer, Thomas; Blaes, Omer; Breedt, Elmé; Scaringi, Simone

Authors

Siddhant Solanki

Thomas Kupfer

Omer Blaes

Elmé Breedt

Dr Simone Scaringi simone.scaringi@durham.ac.uk
Associate Professor

Abstract

We analyse Kepler/K2 light-curve data of the AM CVn system HP Librae (HP Lib). We detect with confidence four photometric periodicities in the system: the orbital frequency, both positive and negative superhumps, and the positive apsidal precession frequency of the accretion disc. This is only the second time that the apsidal precession frequency has ever been directly detected in the photometry of a helium accreting system, after SDSS J135154.46-064309.0. We present phase-folded light curves and sliding power spectra of each of the four periodicities. We measure rates of change of the positive superhump period of ∼10−7 d. We also redetect a quasi-periodic oscillation (QPO) at ∼300 cyc d–1, a feature that has been stable over decades, and show that it is harmonically related to two other QPOs, the lowest of which is centred on the superhump/orbital frequency. The continuum power spectrum is consistent with a single power law with no evidence of any breaks within our observed frequency range.

Citation

Solanki, S., Kupfer, T., Blaes, O., Breedt, E., & Scaringi, S. (2021). Periodicities in the K2 light curve of HP Librae. Monthly Notices of the Royal Astronomical Society, 500(1), 1222-1230. https://doi.org/10.1093/mnras/staa3240

Journal Article Type	Article
Acceptance Date	Oct 15, 2020
Online Publication Date	Oct 20, 2020
Publication Date	2021-01
Deposit Date	Dec 31, 2020
Publicly Available Date	Jun 29, 2021
Journal	Monthly Notices of the Royal Astronomical Society
Print ISSN	0035-8711
Electronic ISSN	1365-2966
Publisher	Royal Astronomical Society
Peer Reviewed	Peer Reviewed
Volume	500
Issue	1
Pages	1222-1230
DOI	https://doi.org/10.1093/mnras/staa3240

Files

Published Journal Article (3 Mb)
PDF

Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©: 2020 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.