Nutze Skyfield fuer praezisere Daemmerungsberechnung

public/py/vendor/skyfield/data/horizons.py

@@ -0,0 +1,26 @@
+"""Physical data for the planets from the JPL HORIZONS system.
+
+To rebuild this data, consult the following IPython Notebook:
+
+https://github.com/brandon-rhodes/astronomy-notebooks/blob/master/Utils-HORIZONS-data.ipynb
+
+"""
+from skyfield.units import Distance
+
+radii_km = [
+    ('Sun', 695500.0),
+    ('Mercury', 2440.0),
+    ('Venus', 6051.8),
+    ('Earth', 6371.01),
+    ('Mars', 3389.9),
+    ('Jupiter', 69911.0),
+    ('Saturn', 58232.0),
+    ('Uranus', 25362.0),
+    ('Neptune', 24624.0),
+    ('134340 Pluto', 1195.0),
+    ]
+
+def festoon_ephemeris(ephemeris):
+    for name, radius_km in radii_km:
+        name = name.lower().split()[-1]
+        getattr(ephemeris, name).radius = Distance(km=radius_km)