Spectroscopic observations of flares and superflares on AU Mic
ABSTRACT The young active flare star AU Mic is the planet host star with the highest flare rate from Transiting Exoplanet Survey Satellite data. Therefore, it represents an ideal target for dedicated ground-based monitoring campaigns with the aim to characterize its numerous flares spectroscopically. We performed such spectroscopic monitoring with the ESO1.52-m telescope of the PLATOSpec consortium. In more than 190 h of observations, we find 24 flares suitable for detailed analysis. We compute their parameters (duration, peak flux, and energy) in eight chromospheric lines (H $\alpha$, H $\beta$, H $\gamma$, H $\delta$, Na i D1&D2, He i D3, He i 6678) and investigate their relationships. Furthermore, we obtained simultaneous photometric observations and low-resolution spectroscopy for part of the spectroscopic runs. We detect one flare in the g$^{\prime }$-band photometry, which is associated with a spectroscopic flare. Additionally, an extreme flare event occurred on 2023-09-16 of which only a time around its possible peak was observed, during which chromospheric line fluxes were raised by up to a factor of three compared to the following night. The estimated energy of this event is around $10^{33}$ erg in H $\alpha$ alone, i.e. a rare chromospheric line superflare.
Authors
- J. Srba
- M. Leitzinger (ORCID: https://orcid.org/0000-0002-5902-9129)
- Rafael Brahm (ORCID: https://orcid.org/0000-0002-9158-7315)
- M. Skarka (ORCID: https://orcid.org/0000-0002-7602-0046)
- Petr Škoda (ORCID: https://orcid.org/0000-0002-7434-9518)
- E. W. Guenther (ORCID: https://orcid.org/0000-0002-9130-6747)
- P. Heinzel (ORCID: https://orcid.org/0000-0002-5778-2600)
- Ján Janík (ORCID: https://orcid.org/0000-0002-6384-0184)
- P. Kábath (ORCID: https://orcid.org/0000-0002-1623-5352)
- R. Karjalainen (ORCID: https://orcid.org/0000-0002-2656-909X)
- P. Odert (ORCID: https://orcid.org/0000-0002-4400-683X)
- R. Greimel (ORCID: https://orcid.org/0000-0001-6421-9640)
- Jiří Wollmann
- L. Vanzi
- J. Lipták
- J. Frýda
Institutions
- University of Graz (AT)
- Pontificia Universidad Católica de Chile (CL)
- Millennium Institute (BR)
- Adolfo Ibáñez University (CL)
- Charles University (CZ)
- Masaryk University (CZ)
- University of Wrocław (PL)
- Czech Academy of Sciences, Astronomical Institute (CZ)
- Graz University of Technology (AT)
- Stellar Science (United States) (US)
- Millennium Institute of Astrophysics (CL)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Astronomical Institute of the Slovak Academy of Sciences (SK)
- Thüringer Landessternwarte Tautenburg (DE)
- Data Observatory Foundation
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2024-12-13
- DOI
- https://doi.org/10.1093/mnras/stae2752
- Citations
- 5
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 1.66
Funders
- National Aeronautics and Space Administration
- European Space Agency
- European Commission
- Austrian Science Fund
- European Southern Observatory
- Uniwersytet Wrocławski
- Agencia Nacional de Investigación y Desarrollo
- Science Mission Directorate
- HORIZON EUROPE Framework Programme
- Institut national des sciences de l'Univers
- H2020 Marie Skłodowska-Curie Actions