Speaker
Description
I will discuss the smallsat SEEJ (Structure & Evolution of ExoJupiter Atmospheres). It will measure both the fluxes of high-energy photons emanating from a flux limited sample of planet-hosting stars and the absorption depth of X-rays in the atmospheres of hot Jupiter, Saturn, and Neptune analogs. SEEJ will measure how often high energy flares of a given size occur, and establish, for the first time, the statistics of these crucial events on exoplanet hosts. Specifically, the SEEJ investigation will determine the degree to which stellar high-energy photons inflate nearby exoplanet atmospheres and the physical characteristics of driven planetary winds. The investigation will determine the bulk composition of the inflated atmosphere and will assess the presence of dense evaporation tails resulting from this interaction. The experimental objective is to measure the high energy fluence through stellar monitoring and understand the impact of the high energy fluence by measuring the atmospheres using the X-ray transit technique.
To accomplish this goal, we need to be able to demonstrate to the astrophysical community at-large a clear connection from the observations to reality. We need to explain what the transit results from a limited set of planets imply for the atmospheric evolution of planets more broadly. This path starts with the detection of a transit followed by a fitted light curve and then inferences about the obstructing material. Finally, we need to demonstrate the implications that the obscuring material has for the underlying atmosphere. In this discussion, I highlight some of our communal shortcomings. For example, while we have recently improved our simulations and the inference they provide, the single existing positive detection of an X-ray transit (HD 189733b) makes it difficult to evaluate or quantify astrophysical and instrumental systematic issues that are associated with general transit simulations. The utility of solar templates for the diverse and different spot coverage of young stars and M dwarfs is undemonstrated.
