TY  - JOUR
A1  - Toalá, Jesús Alberto
A1  - Bowman, Dominic
A1  - Van Reeth, Timothy
A1  - Todt, Helge Tobias
A1  - Dsilva, Karan
A1  - Shenar, Tomer
A1  - Koenigsberger, Gloria Suzanne
A1  - Estrada-Dorado, Sandino
A1  - Oskinova, Lida
A1  - Hamann, Wolf-Rainer
T1  - Multiple variability time-scales of the early nitrogen-rich Wolf-Rayet star WR 7
JF  - Monthly notices of the Royal Astronomical Society
N2  - We present the analysis of the optical variability of the early, nitrogen-rich Wolf-Rayet (WR) star WR 7. The analysis of multisector Transiting Exoplanet Survey Satellite (TESS) light curves and high-resolution spectroscopic observations confirm multiperiodic variability that is modulated on time-scales of years. We detect a dominant period of 2.6433 +/- 0.0005 d in the TESS sectors 33 and 34 light curves in addition to the previously reported high-frequency features from sector 7. We discuss the plausible mechanisms that may be responsible for such variability in WR 7, including pulsations, binarity, co-rotating interaction regions (CIRs), and clumpy winds. Given the lack of strong evidence for the presence of a stellar or compact companion, we suggest that WR 7 may pulsate in quasi-coherent modes in addition to wind variability likely caused by CIRs on top of stochastic low-frequency variability. WR 7 is certainly a worthy target for future monitoring in both spectroscopy and photometry to sample both the short (less than or similar to 1 d) and long (greater than or similar to 1000 d) variability time-scales.
KW  - stars: atmospheres
KW  - stars: evolution
KW  - stars: individual: WR 7
KW  - stars: winds
KW  - outflows
KW  - stars: Wolft-Rayet
Y1  - 2022
U6  - https://doi.org/10.1093/mnras/stac1455
SN  - 0035-8711
SN  - 1365-2966
VL  - 514
IS  - 2
SP  - 2269
EP  - 2277
PB  - Oxford University Press
CY  - Oxford
ER  -