Key to Catalog of Solar Eclipses

Five Millennium Canon of Solar Eclipses [Espenak and Meeus]

Introduction

Tables of solar eclipse local circumstances include the following data. The calendar date and Dynamical Time of the instant of greatest eclipse[1] are found in the first two columns. Delta T (ΔT) gives the arithmetic difference between Dynamical Time and Universal Time. The lunation number (since 2000 Jan 06) and the Saros series are listed along with the eclipse type (P=Partial, A=Annular, T=Total or H=Hybrid[2]) Gamma is the distance of the shadow axis from Earth's center at greatest eclipse while the eclipse magnitude is defined as the fraction of the Sun's diameter obscured at that instant. The geographic latitude and longitude of the umbra are given for greatest eclipse, along with the Sun's altitude and azimuth, the width of the path (kilometers) and the central line duration of totality or annularity. For both partial and non-central umbral/antumbral eclipses, the latitude and longitude correspond to the point closest to the shadow cone axis at greatest eclipse. The Sun's altitude is always 0° at this location.

The data presented in the catalog are based on the Five Millennium Canon of Solar Eclipses: -1999 to +3000.


[1] Greatest eclipse is defined as the instant when the axis of the Moon's shadow passes closest to Earth's center. For total eclipses, the instant of greatest eclipse is virtually identical to the instants of greatest magnitude and greatest duration. However, for annular eclipses, the instant of greatest duration may occur at either the time of greatest eclipse or near the sunrise and sunset points of the eclipse path.

[2] Hybrid eclipses are also known as annular/total eclipses. They occur when the vertex of the Moon's umbral shadow pierces Earth's surface along the central path of an annular eclipse. The eclipse's character then changes to total along the section of the path where the umbral vertex extends beneath Earth's surface. The central paths of hybrid eclipses usually (but not always) begin and end as annular eclipses, but become total along some middle portion of the path.


Key to Catalog of Solar Eclipses

Column     Heading     Definition/Description
          
   1       Catalog     Sequential number of the eclipse in the catalog links to
           Number      the map published in the 
                       Five Millennium Canon of Solar Eclipses: -1999 to +3000. 

   2      Calendar     Calendar Date at instant of Greatest Eclipse. 
            Date       Gregorian Calendar is used for dates after 1582 Oct 15.  
                       Julian Calendar is used for dates before 1582 Oct 04.   

   3         TD of     Dynamical Time (TD) of Greatest Eclipse, the instant 
           Greatest    when the axis of the Moon's shadow cone passes closest
           Eclipse     to Earth's center.

   4         ΔT        Delta T (ΔT) is the arithmetic difference between 
                       Dynamical Time and Universal Time. It is a measure of 
                       the accumulated clock error due to the variable 
                       rotation period of Earth.

   5        Luna       Lunation Number is the number of synodic months since 
             Num       New Moon of 2000 Jan 06. The Brown Lunation Number 
                       can be determined by adding 953.

   6        Saros      Saros series number of eclipse.
             Num       (Each eclipse in a Saros is separated by an interval
                        of 18 years 11.3 days.)

   7        Ecl.       Eclipse Type where:
            Type         P  = Partial Eclipse.
                         A  = Annular Eclipse.
                         T  = Total Eclipse.
                         H  = Hybrid or Annular/Total Eclipse.

                       Second character in Eclipse Type:
                         "m" = Middle eclipse of Saros series.
                         "n" = Central eclipse with no northern limit.
                         "s" = Central eclipse with no southern limit.
                         "+" = Non-central eclipse with no northern limit.
                         "-" = Non-central eclipse with no southern limit.
                         "2" = Hybrid path begins total and ends annular.
                         "3" = Hybrid path begins annular and ends total.
                         "b" = Saros series begins (first eclipse in series).
                         "e" = Saros series ends (last eclipse in series).

   8        Gamma      Distance of the shadow cone axis from the center 
                       of Earth (units of equatorial radii) at the 
                       instant of greatest eclipse.

   9        Ecl.       Eclipse magnitude is the fraction of the Sun's 
            Mag.       diameter obscured by the Moon. For annular, total and 
                       hybrid eclipses, this value is actually the diameter 
                       ratio of Moon/Sun.


  10        Lat.       Latitude where greatest eclipse is seen.

  11        Long.      Longitude where greatest eclipse is seen.

  12        Sun        Sun's altitude at greatest eclipse.
            Alt

  13        Sun        Sun's azimuth at greatest eclipse.
            Azm

  14        Path       Width of the path of totality or annularity
           Width       at greatest eclipse (kilometers).

  15      Central      Central Line Duration of total or annular phase
            Dur.       at greatest eclipse.


Eclipse Predictions

The coordinates of the Sun used in these predictions are based on the VSOP87 theory [Bretagnon and Francou, 1988]. The Moon's coordinates are based on the ELP-2000/82 theory [Chapront-Touze and Chapront, 1983]. For more information, see: Solar and Lunar Ephemerides. The revised value used for the Moon's secular acceleration is n-dot = -25.858 arc-sec/cy*cy, as deduced from the Apollo lunar laser ranging experiment (Chapront, Chapront-Touze, and Francou, 2002).

The largest uncertainty in the eclipse predictions is caused by fluctuations in Earth's rotation due primarily to tidal friction of the oceans due to the Moon. The resultant drift in apparent clock time is expressed as delta-T and was was determined as follows:

  1. pre-1950's: delta T was calculated from empirical fits to historical records derived by Morrison and Stephenson (2004)
  2. 1955-present: delta T was obtained from published observations
  3. future: delta-T was extrapolated from current values weighted by the long term trend from tidal effects

References for Solar Eclipse Predictions

Bretagnon P., Francou G., "Planetary Theories in rectangular and spherical variables: VSOP87 solution", Astron. Astrophys., vol. 202, no. 309 (1988).

Brown, E. W., Tables of the Motion of the Moon, Yale University Press, New Haven, 1919.

Chapront, J., Chapront-Touze, M. and Francou, G., "A new determination of lunar orbital parameters, precession constant and tidal acceleration from LLR measurements", Astron. Astrophys., vol. 387, pp 700-709 (2002).

Chapront-Touze, M and Chapront, J., "The Lunar Ephemeris ELP 2000" , Astron. and Astrophys. vol. 124, no. 1, pp 50-62 (1983).

Eckert, W. J., Jones, R., and Clark, H. K., Improved Lunar Ephemeris 1952-1959, Nautical Almanac Office, U. S. Naval Observatory, Washington, D.C., 1954.

Espenak, F., Fifty Year Canon of Solar Eclipses: 1986Ð2035, NASA RP-1178, Greenbelt, MD, 1987.

Espenak, F. and Meeus, J., Five Millennium Canon of Solar Eclipses: -1999 to +3000, NASA TP-2006-214141, Greenbelt, MD, 2006.

Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac, Her Majesty's Nautical Almanac Office, London, 1974.

Meeus, J., Astronomical Formulae for Calculators, Willmann-Bell, Inc., Richmond, 1982.

Meeus, J., Grosjean, C., and Vanderleen, W., Canon of Solar Eclipses, Pergamon Press, New York, 1966.

Morrison, L. and Stephenson, F. R., "Historical Values of the Earth's Clock Error ΔT and the Calculation of Eclipses", J. Hist. Astron., Vol. 35 Part 3, August 2004, No. 120, pp 327-336 (2004).

Morrison, L.V. and Ward, C. G., "An analysis of the transits of Mercury: 1677-1973", Mon. Not. Roy. Astron. Soc., 173, 183-206, 1975.

Mucke, H., and Meeus, J., Canon of Solar Eclipses -2003 to +2526, Astronomisches Buro, Vienna, 1983.

Newcomb, S., "Tables of the Motion of the Earth on its Axis Around the Sun", Astron. Papers Amer. Eph., Vol. 6, Part I, 1895.

Stephenson F.R and Houlden M.A., Atlas of Historical Eclipse Maps, Cambridge Univ.Press., Cambridge, 1986.


Acknowledgments

Special thanks to Jean Meeus for providing the Besselian elements used in the solar eclipse predictions.

All eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. Some of the information presented on this web site is based on data originally published in Five Millennium Canon of Solar Eclipses: -1999 to +3000.

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

"Eclipse Predictions by Fred Espenak and Jean Meeus (NASA's GSFC)"

2007 Feb 05