تقرير
A BRITE view on the massive O-type supergiant V973 Scorpii: Hints towards internal gravity waves or subsurface convection zones
| العنوان: | A BRITE view on the massive O-type supergiant V973 Scorpii: Hints towards internal gravity waves or subsurface convection zones |
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| المؤلفون: | Ramiaramanantsoa, Tahina, Ratnasingam, Rathish, Shenar, Tomer, Moffat, Anthony F. J., Rogers, Tamara M., Popowicz, Adam, Kuschnig, Rainer, Pigulski, Andrzej, Handler, Gerald, Wade, Gregg A., Zwintz, Konstanze, Weiss, Werner W. |
| سنة النشر: | 2018 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Solar and Stellar Astrophysics |
| الوصف: | Stochastically-triggered photospheric light variations reaching $\sim$$40$ mmag peak-to-valley amplitudes have been detected in the O8Iaf supergiant V973 Scorpii as the outcome of two months of high-precision time-resolved photometric observations with the BRIght Target Explorer (BRITE) nanosatellites. The amplitude spectrum of the time series photometry exhibits a pronounced broad bump in the low-frequency regime ($\lesssim$$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 $5-10$ days. The overall features of the observed brightness amplitude spectrum of V973 Sco match well with 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 subsurface convection zone needs to be explored in future theoretical investigations. Comment: 17 pages, 12 figures, 3 tables; Monthly Notices of the Royal Astronomical Society (MNRAS), in press |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/sty1897 |
| URL الوصول: | http://arxiv.org/abs/1807.04660 |
| رقم الأكسشن: | edsarx.1807.04660 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/sty1897 |
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