<i>TESS</i> and ground-based observations of WZ Sge-type dwarf novae in outburst

ABSTRACT Dwarf nova (DN) superoutbursts are accompanied by superhumps, which change their periods and profiles over a superoutburst. We present the TESS and ground-based observations of nine WZ Sge-type DNe and candidates in superoutburst. In TCP J23580961$+$5502508, ASASSN-23ba, PNV J19030433$-$3102187, V748 Hya, and ASASSN-25ci, we confirmed double-peaked oscillations called early superhumps, which are regarded as the unambiguous feature of WZ Sge-type DNe. On the other hand, the superhump and outburst properties of MO Psc and V1676 Her suggest that they may not be a member of WZ Sge-type DNe. The 2022 superoutburst of a confirmed WZ Sge-type DN TCP J05515391$+$6504346, however, lacked an early superhump phase. We find superhumps in a WZ Sge-type DN ASASSN-20mq during its rebrightening outburst. Due to the continuous coverage of TESS, we find the broken-power-law rise of the outburst light curve in V748 Hya and PNV J19030433$-$3102187, previously found in only one WZ Sge-type DN observed by Kepler. Early superhumps appeared when the system reached $\simeq 40$ per cent of the outburst peak flux. No orbital modulation from a hot spot is detected before and after this. This non-detection of orbital humps on the early rise of V748 Hya constrains that the corresponding mass transfer rate should be below $\simeq 1\times 10^{16}$ g s$^{-1}$, disfavouring an enhancement of a mass transfer rate by an order of magnitude or larger, even if it occurs. The contentious TESS observations also confirm the coexistence of early and ordinary superhumps during their transition and $\le$2-cycle duration of stage A–B superhump transition in V748 Hya.

Authors

Institutions

Publication Details

Journal
Monthly Notices of the Royal Astronomical Society
Published
2025-11-11
DOI
https://doi.org/10.1093/mnras/staf1964
Primary Topic
Astrophysical Phenomena and Observations
Type
article
Field-Weighted Citation Impact
0.00

Funders

Controls
|||
ALL TIME
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
article

TESS and ground-based observations of WZ Sge-type dwarf novae in outburst

Nikita Rawat, Daisaku Nogami, Tomáš Medulka, Е. П. Павленко et al.
Monthly Notices of the Royal Astronomical Society
Astrophysical Phenomena and Observations
article

TESS and ground-based observations of WZ Sge-type dwarf novae in outburst

Nikita Rawat, Daisaku Nogami, Tomáš Medulka, Е. П. Павленко, Daiti Fujii, Philip A. Starr, Tonny Vanmunster, P. Groot, Naoto Kojiguchi, Alexey V. Baklanov, Terumasa Kato, Hiroshi Itoh, Franz-Josef Hambsch, D. A. H. Buckley, Keisuke Isogai, Yusuke Tampo, Kenneth Menzies, Yuji Sano, Kiyoshi Kasai, Tamás Tordai, Stephen B Potter, S. Yu. Shugarov, S. Kiyota, R. Matsumura, Jumpei Ito, Katsura Matsumoto, Jochen Pietz, Pavol A. Dubovský, P. A. Woudt, Stephen M. Brincat, G. Bolt, Berto Monard
article en

Abstract

ABSTRACT Dwarf nova (DN) superoutbursts are accompanied by superhumps, which change their periods and profiles over a superoutburst. We present the TESS and ground-based observations of nine WZ Sge-type DNe and candidates in superoutburst. In TCP J23580961$+$5502508, ASASSN-23ba, PNV J19030433$-$3102187, V748 Hya, and ASASSN-25ci, we confirmed double-peaked oscillations called early superhumps, which are regarded as the unambiguous feature of WZ Sge-type DNe. On the other hand, the superhump and outburst properties of MO Psc and V1676 Her suggest that they may not be a member of WZ Sge-type DNe. The 2022 superoutburst of a confirmed WZ Sge-type DN TCP J05515391$+$6504346, however, lacked an early superhump phase. We find superhumps in a WZ Sge-type DN ASASSN-20mq during its rebrightening outburst. Due to the continuous coverage of TESS, we find the broken-power-law rise of the outburst light curve in V748 Hya and PNV J19030433$-$3102187, previously found in only one WZ Sge-type DN observed by Kepler. Early superhumps appeared when the system reached $\simeq 40$ per cent of the outburst peak flux. No orbital modulation from a hot spot is detected before and after this. This non-detection of orbital humps on the early rise of V748 Hya constrains that the corresponding mass transfer rate should be below $\simeq 1\times 10^{16}$ g s$^{-1}$, disfavouring an enhancement of a mass transfer rate by an order of magnitude or larger, even if it occurs. The contentious TESS observations also confirm the coexistence of early and ordinary superhumps during their transition and $\le$2-cycle duration of stage A–B superhump transition in V748 Hya.

Monthly Notices of the Royal Astronomical SocietyVol. 545(2)
Royal Astronomical Society (GB), Monterey Institute for Research in Astronomy (US), United States Department of State (US), Osaka Kyoiku University (JP), Radboud University Nijmegen (NL), University of Cape Town (ZA), Nayoro City University (JP), The University of Western Australia (AU), University of Basel (CH), American Association of Variable Star Observers (US), Hokkaido University (JP), Slovak Academy of Sciences (SK), Kyoto University (JP), University of Johannesburg (ZA), University of the Free State (ZA), Geophysical Survey (RU), Czech Academy of Sciences, Astronomical Institute (CZ), National Solar Observatory (US), Freiwillige Akademische Gesellschaft (CH), Dubbo Hospital (AU), Bundesdeutsche Arbeitsgemeinschaft für Veränderliche Sterne (DE), IDS (Germany) (DE), Vihorlat Observatory (SK), Queen Astrid Military Hospital (BE), South African Radio Astronomy Observatory (ZA), Hungarian Astronomical Association (HU), Center for Astrophysics Harvard & Smithsonian (US), Astronomical Institute of the Slovak Academy of Sciences (SK), Astronomical Observatory (RS), Crimean Astrophysical Observatory (UA), Karl Landsteiner Society (AT), Bronberg Observatory (ZA), Stichting tot Steun VCVGZ (NL), The University of Tokyo (JP), Universidad de Extremadura (ES)
National Aeronautics and Space Administration, Space Telescope Science Institute, Queen's University Belfast, Queen's University, Nuclear Safety and Security Commission, Agentúra na Podporu Výskumu a Vývoja, Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, Science and Technology Facilities Council
Openalex Percentile: Top 77%
Astrophysical Phenomena and Observations
DOIOpen Access PDFOpenAlex
AI Navigator

Ask Laika to Summarize, Analyze, and Connect papers live on the map.

Summarize Papers & Methodologies

Extract key findings, datasets, and comparative methods across publications.

Benchmark Rankings & Visual Analytics

Rank top research institutions, authors, funders, topics, and journals by Field-Weighted Citation Impact (FWCI) and paper volume with instant charts.

Connect Distant Disciplines

Bridge topological clusters on the map to find hidden collaborative intersections.