Setting Initial Conditions for Planet Wind Calculations

Here are some relevant figures and equations.

First the different regimes

Here is the radius of the wind standoff.

Here is the Hill radius .

Here are parameters for the stellar wind.

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Comments

1. Alice Quillen -- 9 years ago

Some parameters for two well known systems

parameter symbol unit hd209458b hd189733b
star radius 1.20 0.755
star mass 1.148 0.8
planet radius 1.38 1.138
planet mass 0.69 1.138
period days 3.52472 2.21857
semi-major AU 0.04747 0.03142
Star spec type - - G0V K1-K2
Stellar temp K 6092 4875

Values in this table are taken from the exoplanet encyclopedia. See ​http://exoplanet.eu/catalog/hd_189733_b/

Missing in this list is the EUV luminosity which would give an estimate for (wind mass outflow rate). We could take the V. Bourrier and A. Lecavelier des Etangs: Evaporation model 2013, A&A 557, A124 (2013) values for FUV which are 3-4 times that of the Sun.

For reference the solar EUV flux at 1AU is 4.6 erg/cm2/s, reference: Ribas, I., Guinan, E. F., G ̈udel, M., & Audard, M. 2005, ApJ, 622, 680

The Bourrier and Lecavalier des Etangs 2013 paper also gives a recipe on how to estimate Ly profiles from a simulation (from density and velocities).