JWST will be able to observe the atmospheres of rocky planets transiting nearby M dwarfs. The M dwarf triple star system LTT 1445, at a distance of 6.86 pc, hosts some of the nearest rocky terrestrial planets. These planets most likely orbit the M 3.5V star LTT 1445A. During a 28.6 ksec Chandra ACIS-S3 observation we have i) spatially resolved and detected all three stars in the LTT 1445 system, ii) measured the X-ray luminosity of the individual stars, including LTT 1445A, for the first time, iii) studied the flux variability of the X-ray sources and found strong variability from the A and C components, and iv) investigated how the coronal luminosities, temperatures and volume emission measures vary at different activity levels. Combining these X-ray data with upcoming HST ultraviolet observations will allow a differential emission measure (DEM) estimation of the star's EUV spectrum, thereby facilitating modeling of the rocky planets' atmospheres.
@article{arxiv.2209.11314,
title = {X-ray Emission from the Exoplanet Hosting LTT 1445 Triple Star System},
author = {Alexander Brown and Cynthia S. Froning and Allison Youngblood and Kevin France and David J. Wilson and Girish Duvvuri and Yamila Miguel and Hannah Diamond-Lowe},
journal= {arXiv preprint arXiv:2209.11314},
year = {2022}
}
Comments
18 pages, 4 figures. Accepted to The Astronomical Journal (2022 September 1)