The graze zone is typically five to ten kilometers wide and its interior and exterior boundaries can be predicted using the lunar limb profile. Physical Ephemeris of the Antumbral Shadow provides topocentric data and corrections to the path limits due to the true lunar limb profile. At five minute intervals, the table lists the Moon's topocentric horizontal parallax, semi-diameter, relative angular velocity of the Moon with respect to the Sun and lunar libration in longitude. The Sun's center line altitude and azimuth is given, followed by the azimuth of the umbral path. The path corrections to the northern and southern limits are listed as interior and exterior components in order to define the graze zone.
Positive corrections are in the northern sense while negative shifts are in the southern sense.
Corrections to the center line umbral durations due to the lunar limb profile are also included and they are mostly positive. Thus, when added to the central durations given in Detailed Path Coordinates , a slightly shorter central annular phase is predicted. Detailed coordinates for the zones of grazing eclipse at each limit for all land based sections of the path are presented in Detailed Graze Zone Coordinates . Given the uncertainties in the Watts data, these predictions should be accurate to 0.3 arc-seconds. The interior graze coordinates take into account the deepest valleys along the Moon's limb which produce the simultaneous second and third contacts at the path limits.