py·sy·zy·gy
/ˈpīsizijē/ 
noun
1. A fast and general planet transit (syzygy) code written in C and in Python.
2. pysyzygy computes fast lightcurves for the most general case of a massive, eccentric planet orbiting a limb-darkened star. Here's a sample output image of an assymetric transit:
Installation
Clone the repository and run
>>> make
to build the transit module. Add the top-level folder to your $PATH, then call or
import pysyzygy to begin plotting transits!
Calling pysyzygy...
... is super easy.
import numpy as np
# Orbital elements
kwargs = {'rhos': 1.0, # Stellar density in g/cm^3
'MpMs': 0.001, # Planet-star mass ratio
'esw': 0.1, # Eccentricity vectors
'ecw': 0.1,
'per': 1.0, # Period in days
'RpRs': 0.1, # Planet-star radius ratio
't0': 0.0, # Time of first transit in days
'q1': 1.0, # Kipping (2013) quadratic limb darkening coefficients
'q2': 0.0,
'b': 0.5} # Circular impact parameter
# Instantiate a transit object
trn = ps.Transit(**kwargs)
# Now evaluate the lightcurve on a grid of observation times
t = np.arange(0., 10., ps.transit.KEPLONGCAD)
flux = trn(t)Notes
Feel free to change, adapt, or incorporate this code into your project, but please make sure to cite this repository, as well as Mandel and Agol (2002), the transit model on which pysyzygy is based.
