Key to Visibility of Lunar Eclipses

Fred Espenak

Tables of the visibility of lunar eclipses include the following data. The calendar date of the instant of greatest eclipse[1] and the eclipse type (T=Total, P=Partial, or N=Penumbral) are found in the first two columns.

The penumbral and umbral magnitudes of the eclipse are defined at greatest eclipse as the fractions of the Moon's diameter obscured by penumbral and umbral shadows, respectively.

Next, each contact time of the Moon with Earth's penumbral and umbral shadows are listed (in Universal Time [2] ).

Finally, each record is completed with the Moon's Geocentric Right Ascension and Declination at greatest eclipse and the Greenwich Sidereal Time at 00:00 U.T.. A more detailed key is listed below.

[1] Greatest eclipse is defined as the instant when the Moon passes closest to the axis of Earth's shadows. This marks the instant when the Moon is deepest in Earth's shadow(s).

[2] For most practical purposes, Universal Time (UT) is equivalent to Greenwich Mean Time (GMT).

Key to Visibility of Lunar Eclipses


Column     Heading     Definition/Description
          
   1        Date       Calendar Date (Gregorian) at instant of 
                       Greatest Eclipse. 
                       (Julian calendar is used before 1582 Oct 15).

   2        Type       Type of lunar eclipse where:
                         N = Penumbral Eclipse.
                         P = Partial (Umbral) Eclipse.
                         T = Total (Umbral) Eclipse. 
                             (Tc = central total eclipse)

                       If the Type ends with:
                         "m" = Middle eclipse of Saros series.
                         "+" = Central eclipse (Moon north of axis).
                         "-" = Central eclipse (Moon south of axis).
                         "b" = Saros series begins (first eclipse in series).
                         "e" = Saros series ends (last eclipse in series).

   3        Pen.       Penumbral eclipse magnitude is the fraction of 
            Mag.       the Moon's diameter obscured by the penumbra.

   4        Umb.       Umbral eclipse magnitude is the fraction of 
            Mag.       the Moon's diameter obscured by the umbra.
                       (less than 0 for all penumbral eclipses)

   5         P1        Instant of first exterior tangency of Moon with Penumbra.
                       (Penumbral Eclipse Begins)

   6         U1        Instant of first exterior tangency of Moon with Umbra.
                       (Partial Umbral Eclipse Begins)

   7         U2        Instant of first interior tangency of Moon with Umbra.
                       (Total Umbral Eclipse Begins)

   8      Greatest     The instant when the Moon passes closest to 
          Eclipse      the axis of Earth's shadows.  

   9         U3        Instant of last interior tangency of Moon with Umbra.
                       (Total Umbral Eclipse Ends)

  10         U4        Instant of last exterior tangency of Moon with Umbra
                       (Partial Umbral Eclipse Ends)

  11         P4        Instant of last exterior tangency of Moon with Penumbra.
                       (Penumbral Eclipse Ends)

  12        Moon       Geocentric Right Ascension of the Moon 
             RA        at greatest eclipse (hours).

  13        Moon       Geocentric Declination of the Moon 
             Dec       at greatest eclipse (degrees).

  14        GST0       Greenwich Sidereal Time at 00:00 U.T..

Acknowledgments

All eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. Some of the information presented in these tables is based on data originally published in Fifty Year Canon of Lunar Eclipses: 1986 - 2035.

Permission is freely granted to reproduce this data when accompanied by an acknowledgment:

"Eclipse Predictions by Fred Espenak, NASA/GSFC"


Local Visibility of Lunar Eclipses

Five Millennium Catalog of Lunar Eclipses

2005 July 31