A further study of superoutbursts and superhumps in SU UMa stars by the Kepler light curves of V1504 Cygni and V344 Lyrae

作者：Osaki Yoji^*; Kato Taichi

来源：Publications of the Astronomical Society of Japan, 2014, 66(1): 15.

DOI：10.1093/pasj/pst015

• accretion, accretion disks
• novae, cataclysmic variables
• stars: dwarf novae
• stars: individual (V1504 Cygni, V344 Lyrae)

We made a supplementary study of the superoutbursts and superhumps in SU UMa stars by using the recently released Kepler public data of V1504 Cyg and V344 Lyr. One of the superoutbursts in V1504 Cyg was preceded by a precursor normal outburst which was well separated from the main superoutburst. The superhump first appeared during the descending branch of the precursor normal outburst and it continued into its quiescence (the deep dip between the precursor and the main superoutburst), and it began to grow in amplitude with the development of the main superoutburst after the quiescence ended. A similar phenomenon was also observed in V344 Lyr. This observation very clearly demonstrates that the superoutburst was triggered by the superhump (i.e., by the tidal instability), supporting the thermal tidal instability model. Smak (2013, Acta Astron., 63, 109) criticized our previous paper (Osaki & Kato, 2013, PASJ, 65, 50) and challenged our main conclusion that various lines of observational evidence of V1504 Cyg support the thermal tidal instability model for the superoutbursts of SU UMa stars. We present our detailed accounts to all of his criticisms by offering clear explanations. We conclude that the thermal tidal instability model is, after all, only the viable model for the superoutbursts and superhumps in SU UMa stars.

• 出版日期2014-2