@article{7badab143d784cd5955888b3e9750e2d,
title = "Flares, Rotation, and Planets of the AU Mic System from TESS Observations",
abstract = "AU Mic is a young (∼24 Myr), pre-main-sequence M dwarf star that was observed in the first month of science observations of the Transiting Exoplanet Survey Satellite (TESS) and reobserved 2 years later. This target has photometric variability from a variety of sources that is readily apparent in the TESS light curves; spots induce modulation in the light curve, flares are present throughout (manifesting as sharp rises with slow exponential decay phases), and transits of AU Mic b may be seen by eye as dips in the light curve. We present a combined analysis of both TESS Sector 1 and Sector 27 AU Mic light curves including the new 20 s cadence data from TESS Year 3. We compare flare rates between both observations and analyze the spot evolution, showing that the activity levels increase slightly from Sector 1 to Sector 27. Furthermore, the 20 s data collection allows us to detect more flares, smaller flares, and better resolve flare morphology in white light as compared to the 2 minute data collection mode. We also refine the parameters for AU Mic b by fitting three additional transits of AU Mic b from Sector 27 using a model that includes stellar activity. We show that the transits exhibit clear transit timing variations with an amplitude of ∼80 s. We also detect three transits of a 2.8 R ⊕ planet, AU Mic c, which has a period of 18.86 days.",
author = "Gilbert, {Emily A.} and Thomas Barclay and Quintana, {Elisa V.} and Walkowicz, {Lucianne M.} and Vega, {Laura D.} and Schlieder, {Joshua E.} and Teresa Monsue and Cale, {Bryson L.} and Collins, {Kevin I.} and Eric Gaidos and {El Mufti}, Mohammed and Reefe, {Michael A.} and Peter Plavchan and Angelle Tanner and Wittenmyer, {Robert A.} and Wittrock, {Justin M.} and Jenkins, {Jon M.} and Latham, {David W.} and Ricker, {George R.} and Rose, {Mark E.} and S. Seager and Vanderspek, {Roland K.} and Winn, {Joshua N.} and Gilbert, {Emily A.}",
note = "Funding Information: E.A.G. thanks the LSSTC Data Science Fellowship Program, which is funded by LSSTC, NSF Cybertraining Grant #1829740, the Brinson Foundation, and the Moore Foundation; her participation in the program has benefited this work. E.A.G. is thankful for support from GSFC Sellers Exoplanet Environments Collaboration (SEEC), which is funded by the NASA Planetary Science Divisions Internal Scientist Funding Model. The material is based upon work supported by NASA under award number 80GSFC21M0002. This work was also supported by NASA awards 80NSSC19K0104 and 80NSSC19K0315. Funding Information: This work was supported by grants to P.P. and L.V. from NASA (awards 80NSSC20K0251, 80NSSC21K0349, and 80NSSC21K0241), the National Science Foundation (Astronomy and Astrophysics grants 1716202 and 2006517), and the Mount Cuba Astronomical Foundation. Funding Information: This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). Funding for the TESS mission is provided by NASA{\textquoteright}s Science Mission directorate. We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Publisher Copyright: {\textcopyright} 2022. The Author(s). Published by the American Astronomical Society.",
year = "2022",
month = apr,
day = "1",
doi = "10.3847/1538-3881/ac23ca",
language = "English (US)",
volume = "163",
journal = "Astronomical Journal",
issn = "0004-6256",
publisher = "IOP Publishing Ltd.",
number = "4",
}