@article{dfd373969f3a4239902120a7764a48d9,
title = "A BRITE view on the massive O-type supergiant V973 Scorpii: Hints towards internal gravity waves or sub-surface convection zones",
abstract = "Stochastically triggered photospheric light variations reaching ~40 mmag peak-to-valley amplitudes have been detected in the O8 Iaf supergiant V973 Scorpii as the outcome of 2 months of high-precision time-resolved photometric observations with the BRIght Target Explorer (BRITE) nanosatellites. The amplitude spectrum of the time series photometry exhibits a pronounced broad bump in the low-frequency regime (≲0.9 d-1) where several prominent frequencies are detected. A time-frequency analysis of the observations reveals typical mode lifetimes of the order of 5-10 d. The overall features of the observed brightness amplitude spectrum ofV973 Sco matchwellwith those extrapolated from two-dimensional hydrodynamical simulations of convectively driven internal gravity waves randomly excited from deep in the convective cores of massive stars. An alternative or additional possible source of excitation from a sub-surface convection zone needs to be explored in future theoretical investigations.",
keywords = "Convection -waves, Stars: massive, Supergiants, Techniques: photometric",
author = "Tahina Ramiaramanantsoa and Rathish Ratnasingam and Tomer Shenar and Moffat, {Anthony F.J.} and Rogers, {Tamara M.} and Adam Popowicz and Rainer Kuschnig and Andrzej Pigulski and Gerald Handler and Wade, {Gregg A.} and Konstanze Zwintz and Weiss, {Werner W.}",
note = "Funding Information: AFJM acknowledges support from the Canadian Space Agency (CSA), the Natural Sciences and Engineering Research Council of Canada (NSERC), and the Fonds de Recherche du Qu{\'e}bec-Nature et Technologies (FRQNT). APo acknowledges NCN grant 2016/21/D/ST9/00656 and used the infrastructure supported by POIG.02.03.01-24-099/13 grant: GCONiI-Upper-Silesian Center for Scientific Computation. APi acknowledges support from the NCN grant no. 2016/21/B/ST9/01126. The Polish contribution to the BRITE mission is supported by a SPUB grant of the PolishMinistry of Science andHigher Education (MNiSW).GHacknowledges support from the Polish NCN grant 2015/18/A/ST9/00578. GAW acknowledges Discovery Grant support from NSERC. TR was supported in part by science funding related to the BRITE-Toronto mission, awarded by the CSA to GAW on behalf of the Canadian BRITE team. KZ acknowledges support by the Austrian Space Application Programme (ASAP) of the Austrian Research Promotion Agency (FFG). This investigation is based on data collected by the BRITEConstellation satellite mission, designed, built, launched, operated, and supported by the Austrian Research Promotion Agency (FFG), the University of Vienna, the Technical University of Graz, the Canadian Space Agency (CSA), the University of Toronto Institute for Aerospace Studies (UTIAS), the Foundation for Polish Science & Technology (FNiTP MNiSW), and National Science Centre (NCN). Publisher Copyright: {\textcopyright} 2018 The Author(s).",
year = "2018",
doi = "10.1093/MNRAS/STY1897",
language = "English (US)",
volume = "480",
pages = "972--986",
journal = "Monthly Notices of the Royal Astronomical Society",
issn = "0035-8711",
publisher = "Oxford University Press",
number = "1",
}