def propagate_pos(self, phi, theta, parallax, muphistar, mutheta, vrad, t0, t1):
        """
        Propagate the position of a source from the reference epoch t0 to the new epoch t1.

        Parameters
        ----------

        phi : float
            Longitude at reference epoch (radians).
        theta : float
            Latitude at reference epoch (radians).
        parallax : float
            Parallax at the reference epoch (mas).
        muphistar : float
            Proper motion in longitude (including cos(latitude) term) at reference epoch (mas/yr).
        mutheta : float
            Proper motion in latitude at reference epoch (mas/yr).
        vrad : float
            Radial velocity at reference epoch (km/s).
        t0 : float
            Reference epoch (Julian years).
        t1 : float
            New epoch (Julian years).

        Returns
        -------

        Coordinates phi and theta at new epoch (in radians)
        """
        phi1, theta1, parallax1, muphistar1, mutheta1, vrad1 = self.epoch_prop_astrometry(phi, theta, parallax, muphistar, mutheta, vrad, t0, t1)
        return phi1, theta1
def propagate_pos(self, phi, theta, parallax, muphistar, mutheta, vrad, t0, t1):
        """
        Propagate the position of a source from the reference epoch t0 to the new epoch t1.

        Parameters
        ----------

        phi : float
            Longitude at reference epoch (radians).
        theta : float
            Latitude at reference epoch (radians).
        parallax : float
            Parallax at the reference epoch (mas).
        muphistar : float
            Proper motion in longitude (including cos(latitude) term) at reference epoch (mas/yr).
        mutheta : float
            Proper motion in latitude at reference epoch (mas/yr).
        vrad : float
            Radial velocity at reference epoch (km/s).
        t0 : float
            Reference epoch (Julian years).
        t1 : float
            New epoch (Julian years).

        Returns
        -------

        Coordinates phi and theta at new epoch (in radians)
        """
        phi1, theta1, parallax1, muphistar1, mutheta1, vrad1 = self.epoch_prop_astrometry(phi, theta, parallax, muphistar, mutheta, vrad, t0, t1)
        return phi1, theta1
def propagate_pos ( self , phi , theta , parallax , muphistar , mutheta , vrad , t0 , t1 ) : phi1 , theta1 , parallax1 , muphistar1 , mutheta1 , vrad1 = self . epoch_prop_astrometry ( phi , theta , parallax , muphistar , mutheta , vrad , t0 , t1 ) return phi1 , theta1
Propagate the position of a source from the reference epoch t0 to the new epoch t1.

        Parameters
        ----------

        phi : float
            Longitude at reference epoch (radians).
        theta : float
            Latitude at reference epoch (radians).
        parallax : float
            Parallax at the reference epoch (mas).
        muphistar : float
            Proper motion in longitude (including cos(latitude) term) at reference epoch (mas/yr).
        mutheta : float
            Proper motion in latitude at reference epoch (mas/yr).
        vrad : float
            Radial velocity at reference epoch (km/s).
        t0 : float
            Reference epoch (Julian years).
        t1 : float
            New epoch (Julian years).

        Returns
        -------

        Coordinates phi and theta at new epoch (in radians)
Propagate the position of a source from the reference epoch t0 to the new epoch t1 .