Incorrect value used in calcualtion of fundamental argument in nutationlib

[adcl-0]

file: python-skyfield/skyfield/nutationlib.py

 # Mean Anomaly of the Moon.
 fa[0] = ((485868.249036 +
              (715923.2178 +
              (    31.8792 +
              (     0.051635 +
              (    -0.00024470)
              * t) * t) * t) * t) * ASEC2RAD
              + (1325.0*t % 1.0) * tau)

the value in the line 131 should be 1717915923.2178 instead of 715923.2178

[brandon-rhodes]

Changing the value on line 131 breaks Skyfield's high precision agreement with the Naval Observatory's "NOVAS" library. Could you explain what makes you think the value in line 131 should be changed, and where you got your new value from? Thanks!