CONAN.utils.Tdur_to_aR
======================

.. py:function:: CONAN.utils.Tdur_to_aR(Tdur, b, Rp, P, e=0, w=90, tra_occ='tra')

   convert transit duration to scaled semi-major axis
   using eqn 41 of Kipping 2010 https://doi.org/10.1111/j.1365-2966.2010.16894.x
   note (1+p^2) in the equation should instead be (1+p)^2

   :param Tdur: The transit duration in days.
   :type Tdur: float, ufloat, array-like;
   :param b: The impact parameter.
   :type b: float, ufloat, array-like;
   :param Rp: planet-to-star radius ratio.
   :type Rp: float, ufloat, array-like;
   :param P: The period of the planet in days.
   :type P: float, ufloat, array-like;
   :param e: The eccentricity of the orbit.
   :type e: float, ufloat, array-like;
   :param w: The argument of periastron in degrees.
   :type w: float, ufloat, array-like;

   :returns: **aR** -- The scaled semi-major axis of the planet.
   :rtype: array-like;