%0 Generic %1 schmidt2018largest %A Schmidt, Sarah J. %A Shappee, Benjamin J. %A van Saders, Jennifer L. %A Stanek, K. Z. %A Brown, Jonathan S. %A Kochanek, C. S. %A Dong, Subo %A Drout, Maria R. %A Frank, Stephen %A Holoien, Thomas W. S. %A Johnson, Sean %A Madore, Barry F. %A Prieto, Jose L. %A Seibert, Mark %A Seidel, Marja K. %A Simonian, Gregory V. A. %D 2018 %K flares mdwarf %T The largest M dwarfs flares from ASAS-SN %U http://arxiv.org/abs/1809.04510 %X The All-Sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light every $\sim$day, reaching a depth of $g\sim18$ mag. Over the course of its first four years of transient alerts (2013-2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified TT Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in $V$-band contrast from $\Delta V = -1$ to $-10.2$ mags. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the $V$-band energy emitted during each flare, spanning $łog(E_V/ergs)=32$ to $35$, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M-dwarf flare stars show a higher fraction of H$\alpha$ emission as well as stronger H$\alpha$ emission compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old.

@misc{schmidt2018largest, abstract = {The All-Sky Automated Survey for Supernovae (ASAS-SN) is the only project in existence to scan the entire sky in optical light every $\sim$day, reaching a depth of $g\sim18$ mag. Over the course of its first four years of transient alerts (2013-2016), ASAS-SN observed 53 events classified as likely M dwarf flares. We present follow-up photometry and spectroscopy of all 53 candidates, confirming flare events on 47 M dwarfs, one K dwarf, and one L dwarf. The remaining four objects include a previously identified TT Tauri star, a young star with outbursts, and two objects too faint to confirm. A detailed examination of the 49 flare star light curves revealed an additional six flares on five stars, resulting in a total of 55 flares on 49 objects ranging in $V$-band contrast from $\Delta V = -1$ to $-10.2$ mags. Using an empirical flare model to estimate the unobserved portions of the flare light curve, we obtain lower limits on the $V$-band energy emitted during each flare, spanning $\log(E_V/{\rm ergs})=32$ to $35$, which are among the most energetic flares detected on M dwarfs. The ASAS-SN M-dwarf flare stars show a higher fraction of H$\alpha$ emission as well as stronger H$\alpha$ emission compared to M dwarfs selected without reference to activity, consistent with belonging to a population of more magnetically active stars. We also examined the distribution of tangential velocities, finding that the ASAS-SN flaring M dwarfs are likely to be members of the thin disk and are neither particularly young nor old.}, added-at = {2018-09-13T19:23:24.000+0200}, author = {Schmidt, Sarah J. and Shappee, Benjamin J. and van Saders, Jennifer L. and Stanek, K. Z. and Brown, Jonathan S. and Kochanek, C. S. and Dong, Subo and Drout, Maria R. and Frank, Stephen and Holoien, Thomas W. S. and Johnson, Sean and Madore, Barry F. and Prieto, Jose L. and Seibert, Mark and Seidel, Marja K. and Simonian, Gregory V. A.}, biburl = {https://www.bibsonomy.org/bibtex/230b509ff9db955a5ad2de5e51a250887/superjenwinters}, description = {The largest M dwarfs flares from ASAS-SN}, interhash = {0c6eff1ac4bb115d40340209c99da06c}, intrahash = {30b509ff9db955a5ad2de5e51a250887}, keywords = {flares mdwarf}, note = {cite arxiv:1809.04510Comment: 29 pages, 10 figures, 6 tables, submitted to AAS journals (ApJ)}, timestamp = {2018-09-13T19:23:24.000+0200}, title = {The largest M dwarfs flares from ASAS-SN}, url = {http://arxiv.org/abs/1809.04510}, year = 2018 }