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| Auteurs principaux: | , |
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| Format: | Preprint |
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2026
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| Accès en ligne: | https://arxiv.org/abs/2605.09340 |
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| _version_ | 1866913107924746240 |
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| author | Li, Xin Sun, Yongkang |
| author_facet | Li, Xin Sun, Yongkang |
| contents | Nova-like variables are high-accretion-rate cataclysmic variables (CVs) that, in contrast to dwarf novae, do not undergo outbursts caused by thermal-viscous instability. However, a small group of nova-likes, classified as AH Pic-type stars, show recurrent small-amplitude outbursts, which are unexpected by the classical disk instability model. The physical mechanisms underlying these outbursts are not clear. In this study, we present a comprehensive time-domain analysis of the CV candidate GSC 08227-00723 using photometric data from ASAS-SN and TESS. The long-term light curves reveal a sequence of low-amplitude, recurrent stunted outbursts with recurrence times ranging from 30 to 50 days. Notably, these outbursts are frequently preceded by precursor brightenings, a feature reminiscent of super-outbursts in SU UMa stars driven by tidal instability. Period analysis of high-cadence TESS data identifies a coherent periodic modulation at 0.297 d, likely the orbital period, and a persistent positive superhump signal at 0.352 d. The latter corresponds to an exceptionally large superhump excess of $ε^+ \approx 0.19$, surpassing typical values seen in CVs. Additionally, we detect short-timescale variability resembling quasi-periodic oscillations in the TESS light curves. Based on the outburst properties and photometric behavior, we classify GSC 08227-00723 as a new member of the AH Pic subclass of nova-like stars. We discuss how tidal effects may be involved in the observed behavior, although the exact mechanism is still unclear. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2605_09340 |
| institution | arXiv |
| publishDate | 2026 |
| record_format | arxiv |
| spellingShingle | GSC 08227-00723: An Unusually Large PSH Excess AH Pic Candidate Li, Xin Sun, Yongkang Solar and Stellar Astrophysics Nova-like variables are high-accretion-rate cataclysmic variables (CVs) that, in contrast to dwarf novae, do not undergo outbursts caused by thermal-viscous instability. However, a small group of nova-likes, classified as AH Pic-type stars, show recurrent small-amplitude outbursts, which are unexpected by the classical disk instability model. The physical mechanisms underlying these outbursts are not clear. In this study, we present a comprehensive time-domain analysis of the CV candidate GSC 08227-00723 using photometric data from ASAS-SN and TESS. The long-term light curves reveal a sequence of low-amplitude, recurrent stunted outbursts with recurrence times ranging from 30 to 50 days. Notably, these outbursts are frequently preceded by precursor brightenings, a feature reminiscent of super-outbursts in SU UMa stars driven by tidal instability. Period analysis of high-cadence TESS data identifies a coherent periodic modulation at 0.297 d, likely the orbital period, and a persistent positive superhump signal at 0.352 d. The latter corresponds to an exceptionally large superhump excess of $ε^+ \approx 0.19$, surpassing typical values seen in CVs. Additionally, we detect short-timescale variability resembling quasi-periodic oscillations in the TESS light curves. Based on the outburst properties and photometric behavior, we classify GSC 08227-00723 as a new member of the AH Pic subclass of nova-like stars. We discuss how tidal effects may be involved in the observed behavior, although the exact mechanism is still unclear. |
| title | GSC 08227-00723: An Unusually Large PSH Excess AH Pic Candidate |
| topic | Solar and Stellar Astrophysics |
| url | https://arxiv.org/abs/2605.09340 |