HISTORICAL VALUES OF THE EARTH'S CLOCK ERROR ΔT AND THE CALCULATION OF ECLIPSES

摘要

For the most precise calculations of the local circumstances of solar eclipses, we recommend that researchers use values of ΔT taken by linear interpolation from Table 1, combined with a modern ephemeris of the Moon which has a value for the tidal acceleration of the Moon close to -26"cy~2. For extrapolation beyond the limits of Table 1 we recommend ΔT = - 20 + 32[(year -1820)/100]~2 sec. Some empirical adjustment will be required to merge this long-term approximation with extrapolation forward from the precise values formed from ΔT = TAI - DT1+ 32.184 sec.