A Coupled Analysis of Atmospheric Mass Loss and Tidal Evolution in XUV Irradiated Exoplanets: The TRAPPIST-1 Case Study
Abstract
Exoplanets residing close to their stars can experience evolution of both their physical structures and their orbits due to the influence of their host stars. In this work, we present a coupled analysis of dynamical tidal dissipation and atmospheric mass loss for exoplanets in X-ray and ultraviolet (XUV) irradiated environments. As our primary application, we use this model to study the TRAPPIST-1 system and place constraints on the interior structure and orbital evolution of the planets. We start by reporting on an ultraviolet continuum flux measurement (centered around ~1900 Å) for the star TRAPPIST-1, based on 300 ks of Neil Gehrels Swift Observatory data, and which enables an estimate of the XUV-driven thermal escape arising from XUV photodissociation for each planet. We find that the X-ray flaring luminosity, measured from our X-ray detections, of TRAPPIST-1 is 5.6 × 10⁻⁴ L*, while the full flux including non-flaring periods is 6.1 × 10⁻⁵ L*, when L* is TRAPPIST-1's bolometric luminosity. We then construct a model that includes both atmospheric mass loss and tidal evolution and requires the planets to attain their present-day orbital elements during this coupled evolution. We use this model to constrain the ratio Q′ = 3Q/2k₂ for each planet. Finally, we use additional numerical models implemented with the Virtual Planet Simulator VPLanet to study ocean retention for these planets using our derived system parameters.
Additional Information
© 2020 The American Astronomical Society. Received 2019 October 1; revised 2020 April 6; accepted 2020 April 24; published 2020 May 26. We thank the referee for a useful report. We thank Sarah Peacock and Francesco Haardt for assistance. We also thank Andrew Vanderburg, Eric Agol, Konstantin Batygin, Erik Petigura, Erin May, and Beate Stelzer for useful conversations. During this work, J.C.B. has been supported by the Leinweber Center for Theoretical Physical Graduate Fellowship and the Heising-Simons 51 Pegasi b postdoctoral fellowship. R.B. acknowledges support from the NASA Astrobiology Program grant No. 80NSSC18K0829.Attached Files
Published - Becker_2020_AJ_159_275.pdf
Accepted Version - 2005.01740.pdf
Files
Name | Size | Download all |
---|---|---|
md5:13877f60624fa65c55e1a38a988e6f06
|
604.7 kB | Preview Download |
md5:85f0d754418acb008482ba6bcaf6cd99
|
1.2 MB | Preview Download |
Additional details
- Eprint ID
- 103469
- Resolver ID
- CaltechAUTHORS:20200526-143420880
- Leinweber Center for Theoretical Physics
- 51 Pegasi b Fellowship
- Heising-Simons Foundation
- 80NSSC18K0829
- NASA
- Created
-
2020-05-26Created from EPrint's datestamp field
- Updated
-
2021-11-16Created from EPrint's last_modified field