Physics & Astronomy Faculty Publications
Document Type
Article
Publication Date
5-6-2026
Abstract
We present the longest-term optical analysis of the AM CVn system KL Dra using ∼11 yr of monitoring from TESS and wide-field ground-based surveys. The continuous TESS coverage allows us to characterise its frequent outbursts with unprecedented detail, providing the first comprehensive study of an AM CVn during outbursts and enabling detailed modelling of these systems. The superoutbursts in KL Dra generally include a precursor and are followed by a series of rebrightenings after which a sequence of 3–4 large amplitude normal outbursts is observed. We fit parametric profiles to each superoutburst component (precursor, rise to plateau, plateau, and decay), to rebrightenings, and to normal outbursts, which let us quantify every high state feature and investigate correlations with the system’s long-term supercyle evolution. Our continuous coverage reveals an average value for the supercycles, superoutbursts, and normal outbursts of 60.4 ±0.1 d, 5.67 ±0.03 d and 1.17 ±0.01 d, respectively. The supercycle duration may be correlated with the rebrightenings duration and superoutburst amplitude, and anticorrelated with the plateau length. Within a supercycle, normal outbursts grow in amplitude and duration, and the first normal outburst is usually highly asymmetric, while subsequent normal outbursts are more symmetric. We detected superhumps in TESS superoutbursts but not in the rebrightenings or normal outbursts. We interpret the results within the disc instability model, considering additional effects, such as changes in the donor mass transfer rate.
Recommended Citation
Manzano, Luis E. Salazar, Liliana E. Rivera Sandoval, Jean-Marie Hameury, et al. 2026. “KL Dra as a Benchmark Laboratory for Accretion-Disk Physics: Constraints from TESS and Ground-Based Surveys.” Publications of the Astronomical Society of Australia 43 (January): e070. https://doi.org/10.1017/pasa.2026.10203.
Publication Title
Publications of the Astronomical Society of Australia
DOI
10.1017/pasa.2026.10203
Comments
© The Author(s), 2026. Published by Cambridge University Press on behalf of Astronomical Society of Australia This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution and reproduction, provided the original article is properly cited.