code: def pix2sky_vec(self, pixel, r, theta):
          
          ra1, dec1 = self.pix2sky(pixel)
          x, y = pixel
          a = [x + r * np.cos(np.radians(theta)),
               y + r * np.sin(np.radians(theta))]
          locations = self.pix2sky(a)
          ra2, dec2 = locations
          a = gcd(ra1, dec1, ra2, dec2)
          pa = bear(ra1, dec1, ra2, dec2)
          return ra1, dec1, a, pa
docs: Given and input position and vector in pixel coordinates, calculate
          the equivalent position and vector in sky coordinates.
  
          Parameters
          ----------
          pixel : (int,int)
              origin of vector in pixel coordinates
          r : float
              magnitude of vector in pixels
          theta : float
              angle of vector in degrees
  
          Returns
          -------
          ra, dec : float
              The (ra, dec) of the origin point (degrees).
          r, pa : float
              The magnitude and position angle of the vector (degrees).