TY - JOUR
T1 - Bridging the Gap
T2 - OPTICAM Reveals the Hidden Spin of the WZ Sge Star GOTO 065054.49+593624.51
AU - Castro Segura, N.
AU - Irving, Z. A.
AU - Vincentelli, Federico
AU - Altamirano, D.
AU - Tampo, Y.
AU - Knigge, C.
AU - Pelisoli, I.
AU - Coppejans, D. L.
AU - Rawat, N.
AU - Castro, A.
AU - Sahu, A.
AU - Santisteban, J. V. Hernández
AU - Kimura, M
AU - Veresvarska, M.
AU - Michel, R.
AU - Scaringi, S.
AU - Najera, M R
N1 - This is an Open Access article distributed under the terms of the Creative
Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium,
provided the original work is properly cited.
PY - 2025/4/24
Y1 - 2025/4/24
N2 - WZ Sge stars are highly evolved accreting white dwarf systems (AWDs) exhibiting remarkably large amplitude outbursts (a.k.a. super-outbursts), typically followed by short rebrightenings/echo outbursts. These systems have some of the lowest mass transfer rates among AWDs, making even low magnetic fields dynamically important. Such magnetic fields are often invoked to explain the phenomenology observed in these systems, such as their X-ray luminosity and long periods of quiescence (30+ years). However, the detection of these is very elusive given the quenching of the accretion columns during outburst and the low luminosity of these systems during quiescence. Here we present high-cadence multi-band observations with {\it OPTICAM} of the recent outburst of the recently discovered WZ Sge star GOTO065054.49+593624.51, during the end of the main outburst and the dip in-between rebrightenings, covering 2 orders of magnitude in brightness. Our observations reveal the presence of a statistically significant signal with $P_ω\simeq148$ seconds in the bluer ($g$) band which is detected only during the dip between the main outburst and the rebrigthenings. We interpret this signal as the spin period of the AWD. If confirmed, GOTO 0650 would bridge the gap between intermediate- and fast-rotating intermediate polars (IPs) below the period gap.
AB - WZ Sge stars are highly evolved accreting white dwarf systems (AWDs) exhibiting remarkably large amplitude outbursts (a.k.a. super-outbursts), typically followed by short rebrightenings/echo outbursts. These systems have some of the lowest mass transfer rates among AWDs, making even low magnetic fields dynamically important. Such magnetic fields are often invoked to explain the phenomenology observed in these systems, such as their X-ray luminosity and long periods of quiescence (30+ years). However, the detection of these is very elusive given the quenching of the accretion columns during outburst and the low luminosity of these systems during quiescence. Here we present high-cadence multi-band observations with {\it OPTICAM} of the recent outburst of the recently discovered WZ Sge star GOTO065054.49+593624.51, during the end of the main outburst and the dip in-between rebrightenings, covering 2 orders of magnitude in brightness. Our observations reveal the presence of a statistically significant signal with $P_ω\simeq148$ seconds in the bluer ($g$) band which is detected only during the dip between the main outburst and the rebrigthenings. We interpret this signal as the spin period of the AWD. If confirmed, GOTO 0650 would bridge the gap between intermediate- and fast-rotating intermediate polars (IPs) below the period gap.
KW - accretion, accretion discs
KW - stars: dwarf novae
KW - stars: individual: GOTO 065054.49+593624.51
UR - https://doi.org/10.1093/mnrasl/slaf038
U2 - 10.1093/mnrasl/slaf038
DO - 10.1093/mnrasl/slaf038
M3 - Article
SN - 1745-3925
VL - 541
SP - L28-L34
JO - Monthly Notices of the Royal Astronomical Society: Letters
JF - Monthly Notices of the Royal Astronomical Society: Letters
IS - 1
ER -