Poster Open Access

Redefining the Neupert Effect in M Dwarfs through Multi-Wavelength Timing Analysis of AU Mic's Flares

Tristan, Isaiah I.; Notsu, Yuta; Kowalski, Adam F.; Brown, Alexander; Vrijmoet, Eliot H.; Allred, Joel C.; Carter, Brad D.; Grady, Carol A.; Henry, Todd J.; Hinojosa, Rodrigo H.; Jao, Wei-Chun; Lomax, Jamie R.; Neff, James E.; Osten, Rachel A.; Paredes, Leonardo A.; Schneider, Glenn H.; Soutter, Jack; White, Graeme L.; Wisniewski, John P.

Wolk, Scott

M dwarfs are considered one of the most likely places to find extraterrestrial life in part due to their large numbers in the nearby solar neighborhood. However, they have much more intense flaring events than stars like our Sun, which could negatively impact the habitability of close-in exoplanets. Our current understanding of the multi-wavelength connections of M dwarf flaring events is surprisingly far from complete, both in wavelength coverage and temporal resolution. To rectify this, our team collected multi-wavelength data of the dM1e flare star AU Mic over 7-days using a variety of telescopes. Here, we focus on data from XMM-Newton and the Las Cumbres Observatory Global Telescope (LCOGT) network. We discuss the Neupert effect among the X-ray, UV, and optical response in a sample of high-energy flares and present cumulative flare frequency distribution (CFFD) statistics. We find that AU Mic’s U-band CFFD is consistent with other M dwarfs in the literature and that the Neupert effect (i.e. the X-ray derivative peak and NUV peak timings overlap) is not present in all characterized flares. We propose a new Neupert classification system that includes Quasi-Neupert (response in X-ray and NUV, but the timings do not match) and Non-Neupert (missing a response from either X-ray or NUV). Future work on this project includes adding existing AU Mic radio and H-alpha observations to our analysis and using our RADYN flare modeling program to determine the electron beam heating, proton beam heating, and magnetic mirroring needed to reproduce the full range of multi-wavelength responses we see in observations.

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  • Veronig, Astrid M. et al. (2005). Physics of the Neupert Effect: Estimates of the Effects of Source Energy, Mass Transport, and Geometry Using RHESSI and GOES Data.

  • Smith, David S. et al. (2004). Importance of Biologically Active Aurora-like Ultraviolet Emission: Stochastic Irradiation of Earth and Mars by Flares and Explosions.

  • Walker, A. R. (1981). Flare activity of proxima Cen.

  • Lacy, C. H. (1976). UV Ceti stars: statistical analysis of observational data.

  • McTiernan, James M. et al. (1999). The Solar Flare Soft X-Ray Differential Emission Measure and the Neupert Effect at Different Temperatures.

  • Veronig, Astrid M. et al. (2002). Investigation of the Neupert effect in solar flares. I. Statistical properties and the evaporation model.

  • Carlsson & Stein, (1997). Formation of Solar Calcium H and K Bright Grains.

  • Allred, Joel C. et al. (2015). A Unified Computational Model for Solar and Stellar Flares.

  • Gershberg, R. E. (1972). Some results of the cooperative photometric observations of the UV Cet-type flare stars in the years 1967 71.

  • Mitra-Kraev, U. et al. (2005). Relationship between X-ray and ultraviolet emission of flares from dMe stars observed by XMM-Newton

  • Kowalski, Adam F. et al (2013). Time-resolved Properties and Global Trends in dMe Flares from Simultaneous Photometry and Spectra.

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