CAOSP abstracts, Volume: 49, No.: 2, year: 2019

Author(s): Pavlenko, E.; Niijima, K.; Mason, P.; Wells, N.; Sosnovskij, A.; Antonyuk, K.; Simon, A.; Pit, N.; Littlefield, C.; Itoh, H.; Kiyota, S.; Tordai, T.; Dubovsky, P.; Vanmunster, T.; Stone, G.; Kato, T.; Sergeev, A.; Godunova, V.; Lyumanov, E.; Antonyuk, O.; Baklanov, A.; Babina, Ju.; Isogai, K.; Romanyuk, Ya.; Troianskyi, V.; Kashuba, V.
Journal: Contributions of the Astronomical Observatory Skalnaté Pleso, vol. 49, no. 2, p. 204-216.
Date: 5/2019
Title: ASASSN-18fk: A new WZ Sge-type dwarf nova with multiple rebrightenings and a new candidate for a superhumping intermediate polar
Keyword(s): accretion, accretion disks, cataclysmic variables, stars: dwarf novae, stars: individual: ASASSN-18fk
Pages: 204 -- 216
License: This work is licensed under a Creative Commons Attribution 4.0 International License

Abstract: We present the result of a multi-longitude campaign on the photometric study of the dwarf nova ASASSN-18fk during its superoutburst in 2018. It was observed with 18 telescopes at 15 sites during ∼ 70 nights within a three-month interval. Observations covered the main outburst, six rebrightenings and 50-d decline to a near-quiescent state. We identify ASASSN-18fk as а WZ Sge-type dwarf nova with multiple rebrightenings and show the evolution of the 0.06-d superhump period over all stages of the superoutburst. A strong 22-min brightness modulation that superimposed on superhumps is found during rebrightenings and decline. Some evidence of this modulation in a form of a sideband signal is detected during the very onset of the outburst. We interpret the 22-min modulation as a spin period of the white dwarf and suggest that ASASSN-18fk is a good candidate for a superhumping intermediate polar.