GOTO065054+593624: An 8.5 mag amplitude dwarf nova identified in real time via Kilonova Seekers

Abstract

Dwarf novae are astrophysical laboratories for probing the nature of accretion, binary mass transfer, and binary evolution, but their diverse observational characteristics continue to challenge our theoretical understanding. We here present the discovery of and subsequent observing campaign on GOTO065054+593624 (hereafter GOTO0650), a dwarf nova of the WZ Sge type that was discovered in real-time by citizen scientists via the Kilonova Seekers citizen science project. The nova has an outburst amplitude of 8.5 mag. An extensive dataset charts the photometric and spectroscopic evolution of this object, and it covers the 2024 superoutburst. GOTO0650 shows an absence of visible emission lines during the high state, strong H and barely detected He II emission, and high-amplitude echo outbursts on a rapidly decreasing timescale. The comprehensive dataset we present marks GOTO0650 as a candidate period bouncer, and it highlights the important contribution made by citizen scientists to the study of Galactic transients.

Metadata

Item Type:	Article
Authors/Creators:	Killestein, T.L. https://orcid.org/0000-0002-0440-9597 Ramsay, G. https://orcid.org/0000-0001-8722-9710 Kennedy, M. Kelsey, L. https://orcid.org/0000-0003-0313-0487 Steeghs, D. Littlefair, S. https://orcid.org/0000-0001-7221-855X Godson, B. https://orcid.org/0000-0003-3766-7266 Lyman, J. https://orcid.org/0000-0002-3464-0642 Pursiainen, M. https://orcid.org/0000-0003-4663-4300 Warwick, B. https://orcid.org/0009-0005-8379-3871 Krawczyk, C. https://orcid.org/0000-0001-9233-2341 Nuttall, L.K. https://orcid.org/0000-0002-8599-8791 Wickens, E. https://orcid.org/0009-0004-0357-2239 Alexandrov, S.D. https://orcid.org/0000-0002-4959-8598 da Silva, C.M. https://orcid.org/0000-0001-8953-9149 Leadbeater, R. Ackley, K. Dyer, M.J. https://orcid.org/0000-0003-3665-5482 Jiménez-Ibarra, F. Ulaczyk, K. Galloway, D.K. Dhillon, V.S. https://orcid.org/0000-0001-5944-4480 O’Brien, P. Noysena, K. Kotak, R. https://orcid.org/0000-0001-5455-3653 Breton, R.P. https://orcid.org/0000-0001-8522-4983 Pallé, E. https://orcid.org/0000-0003-0987-1593 Pollacco, D. Kumar, A. O’Neill, D. Butterley, T. https://orcid.org/0000-0002-2853-0834 Wilson, R. Mattila, S. Sahu, A. Starling, R. https://orcid.org/0000-0001-5803-2038 Wang, C.Y. Liu, Q. Li, A. Dai, Z. https://orcid.org/0000-0002-4280-6630 Feng, H. Yuan, W. Billington, R. Bull, A.G. https://orcid.org/0009-0008-9709-7836 Gaudenzi, S. Gonano, V. Krawczyk, H. Mazzucato, M.T. https://orcid.org/0000-0002-2204-6064 Pasqua, A. da Silva Campos, J.A. Torres-Guerrero, M. https://orcid.org/0000-0002-3878-7166 Antonov, N.N. https://orcid.org/0009-0002-1484-7029 Bean, S.J. Boeneker, E.T. Brincat, S.M. https://orcid.org/0000-0002-9205-5329 Darlington, G.S. https://orcid.org/0009-0002-7069-6851 Dubois, F. Hambsch, F.-J. https://orcid.org/0000-0003-0125-8700 Messier, D. Oksanen, A. https://orcid.org/0000-0001-6249-6062 Poyner, G. Romanov, F.D. https://orcid.org/0000-0002-5268-7735 Sharp, I.D. Tordai, T. Vanmunster, T. https://orcid.org/0000-0002-8116-6429 Wenzel, K.
Copyright, Publisher and Additional Information:	© The Authors 2025. Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Keywords:	binaries: close; stars: dwarf novae; novae; cataclysmic variables
Dates:	Accepted: 7 May 2025 Published (online): 1 July 2025 Published: July 2025
Institution:	The University of Sheffield
Academic Units:	The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematical and Physical Sciences
Funding Information:	Funder Grant number SCIENCE AND TECHNOLOGY FACILITIES COUNCIL ST/V000853/1
Depositing User:	Symplectic Sheffield
Date Deposited:	08 Jul 2025 15:49
Last Modified:	09 Jul 2025 12:17
Status:	Published
Publisher:	EDP Sciences
Refereed:	Yes
Identification Number:	10.1051/0004-6361/202553823
Related URLs:	Dataset Dataset
Open Archives Initiative ID (OAI ID):	oai:eprints.whiterose.ac.uk:228938