Optical spectroscopic and photometric classification of the X-ray transient EP240309a (EP J115415.8−501810) as an intermediate polar

Potter, Stephen B; Buckley, David A H; Scaringi, S; Monageng, I M; Egbo, Okwudili D; Charles, Philip A; Erasmus, N; van Gend, Carel; Loubser, Egan; Titus, Keegan; Rosie, Kathryn; Gajjar, Hitesh; Worters, H L; Chandra, Sunil; Julie, R P M; Hlakola, Moloko

doi:10.1093/mnrasl/slae038

Optical spectroscopic and photometric classification of the X-ray transient EP240309a (EP J115415.8−501810) as an intermediate polar

Potter, Stephen B; Buckley, David A H; Scaringi, S; Monageng, I M; Egbo, Okwudili D; Charles, Philip A; Erasmus, N; van Gend, Carel; Loubser, Egan; Titus, Keegan; Rosie, Kathryn; Gajjar, Hitesh; Worters, H L; Chandra, Sunil; Julie, R P M; Hlakola, Moloko

Authors

Stephen B Potter

David A H Buckley

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

I M Monageng

Okwudili D Egbo

Philip A Charles

N Erasmus

Carel van Gend

Egan Loubser

Keegan Titus

Kathryn Rosie

Hitesh Gajjar

H L Worters

Sunil Chandra

R P M Julie

Moloko Hlakola

Abstract

We report on optical follow-up observations of an X-ray source initially detected by the Einstein Probe mission. Our investigations categorize the source as an intermediate polar, a class of magnetic cataclysmic variables, exhibiting an orbital period of 3.7614(4) h and a white dwarf spin period of 3.97 min. The orbital period was identified through TESS observations, while our high-speed photometric data, obtained using the 1.9m and Lesedi 1.0m telescopes at the South African Astronomical Observatory, revealed both the spin and beat periods. Additionally, we present orbitally phase-resolved spectroscopic observations using the 1.9m telescope, specifically centred on the H β emission line, which reveal two emission components that exhibit Doppler variations throughout the orbital cycle.

Citation

Potter, S. B., Buckley, D. A. H., Scaringi, S., Monageng, I. M., Egbo, O. D., Charles, P. A., …Hlakola, M. (2024). Optical spectroscopic and photometric classification of the X-ray transient EP240309a (EP J115415.8−501810) as an intermediate polar. Monthly Notices of the Royal Astronomical Society: Letters, 532(1), L21-L26. https://doi.org/10.1093/mnrasl/slae038

Journal Article Type	Article
Acceptance Date	Apr 29, 2024
Online Publication Date	May 6, 2024
Publication Date	May 20, 2024
Deposit Date	Jul 8, 2024
Publicly Available Date	Jul 8, 2024
Journal	Monthly Notices of the Royal Astronomical Society: Letters
Electronic ISSN	1745-3933
Publisher	Oxford University Press
Peer Reviewed	Peer Reviewed
Volume	532
Issue	1
Pages	L21-L26
DOI	https://doi.org/10.1093/mnrasl/slae038
Public URL	https://durham-repository.worktribe.com/output/2521659

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