Planet Tools

Useful functions to perform everyday conversions and calculation of quantities in exoplanetary science. It is a work in progress, so I am constantly adding and modifying them.

To install

pip install Planet-tools

or

git clone https://github.com/tundeakins/Planet_tools.git
cd Planet_tools
python setup.py install

The convert_params module contains the following functions:

• P_to_aR - convert period to scaled semi-major axis.

• aR_to_rho_star - Compute transit derived stellar density from the planet period and scaled semi major axis

• impact_parameter - Convert inclination to impact parameter b

• inclination - Convert impact parameter b to inclination in degrees.

• convert_LD_coeffs - Convert between different LD laws The calculate_params module contains the follwing functions:

• RL_Rroche - Calculate ratio of Laplace radius to Roche radius

• R_hill - Compute the hill radius of a planet

• R_roche - Compute roche radius of a planet as a function of the planet's radius

• T_eq - Calculate equilibrium temperature of planet in Kelvin

• ingress_duration - Calculate the duration of ingress/egress.

• ldtk_ldc - Estimate quadratic limb darkening coefficients for a given star

• phase_fold - Given the observation time and period, return the phase of each observation time

• planet_prot - Calculate period of rotation of a planet

• sigma_CCF - Calculate CCF width of non-rotating star in km/s based on resolution of spectrograph

• transit_duration - Calculate the transit duration

The estimate_effect module contains the following functions:

• photo_granulation - Estimate the amplitude and timescale of granulation noise in photometric observations as given by Gilliland 2011
• chaplin_exptime - Compute the optimal exposure time to reduce stellar p-mode oscillation amplitude in the given star to 0.1m/s and 0.09m/s according to Chaplin et al. 2019.
• rv_precision_degrade - Calculate factor by which RV precision of a stellar spectral type degrades due to vsini.

The some_stats module contains the following functions:

• bic - Compute the bayesian information criteria
• aic - Calculate the Aikake information criterion.
• rmse - Calculate the root-mean-square of the inputed error array (residuals)
• sse - Calculate the sum of squared error of inputed error array (residuals)
• mse - Calculate the mean-square error of imputed error array
• mae - Calculate the mean-absolute error of imputed error array
• rse - Calculate the relative-square error from the observed and calculated values
• rae - Calculate the relative-absolute error from the observed and calculated values
• r_squared - Calculate the R2_score commonly