The Mega-MUSCLES Spectral Energy Distribution of TRAPPIST-1

WILSON, DAVID J.; FRONING, CYNTHIA S.; DUVVURI, GIRISH M.; FRANCE, KEVIN; YOUNGBLOOD, ALLISON; SCHNEIDER, P. CHRISTIAN; BERTA-THOMPSON, ZACHORY; BROWN, ALEXANDER; BUCCINO, ANDREA P.; HAWLEY, SUZANNE; IRWIN, JONATHAN; KALTENEGGER, LISA; KOWALSKI, ADAM; LINSKY, JEFFREY; PARKE LOYD, R.O.; MIGUEL, YAMILA; PINEDA, J. SEBASTIAN; REDFIELD, SETH; ROBERGE, AKI; RUGHEIMER, SARAH; TIAN, FENG; VIEYTES, MARIELA

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Año: 2021 vol. 911

0004-637X

We present a 5 Å-100 μm spectral energy distribution (SED) of the ultracool dwarf star TRAPPIST-1, obtained as part of the Mega-MUSCLES Treasury Survey. The SED combines ultraviolet and blue-optical spectroscopy obtained with the Hubble Space Telescope, X-ray spectroscopy obtained with XMM-Newton, and models of the stellar photosphere, chromosphere, transition region, and corona. A new differential emission measure model of the unobserved extreme-ultraviolet spectrum is provided, improving on the Lyα-EUV relations often used to estimate the 100-911 Å flux from low-mass stars. We describe the observations and models used, as well as the recipe for combining them into an SED. We also provide a semiempirical, noise-free model of the stellar ultraviolet spectrum based on our observations for use in atmospheric modeling of the TRAPPIST-1 planets.