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Besselian Elements - Total Solar Eclipse of 1991 July 11

   Instant of          19:07:01 TDT     JD = 2448449.29700 
Greatest Eclipse:    (=19:6:3 UT)

Gamma = -0.0041            Ephemerides  = VSOP87/ELP2000-82 
Eclipse Magnitude = 1.0800             Lunation No. = -105 
     Eclipse Type = Tm                 Saros Series = 136 
                                                 ΔT = 57.9 s

Lunar Radius   k1 = 0.272488 (Penumbra)        Shift in      Δb =  0.00"
 Constants:    k2 = 0.272281 (Umbra)       Lunar Position:   Δl =  0.00"


Polynomial Besselian Elements for:   1991 Jul 11   19.000 TDT  (=t0)

  n        x          y         d          l1         l2          μ

  0  -0.0672590  0.0121270 22.0974293  0.5304140 -0.0156450 103.639778 
  1   0.5671376 -0.1379772 -0.0052200  0.0000252  0.0000251  15.000060 
  2  -0.0000369 -0.0001529 -0.0000050 -0.0000128 -0.0000127   0.000000 
  3  -0.0000096  0.0000025  0.0000000  0.0000000  0.0000000   0.000000
  
                tan f1 = 0.0045986        tan f2 = 0.0045757 

At time t1 (decimal hours), each Besselian element is evaluated by:

a = a0 + a1*t + a2*t2 + a3*t3  

where: a = x, y, d, l1, l2, or μ; t = t1 - t0 (decimal hours), and t0 =  19.000 TDT.


Circumstances at Greatest Eclipse:  19:6:3 UT

Latitude:   22.0° N      Sun’s Altitude:    89.9°          Path Width = 258.0 km
Longitude: 105.2° W      Sun’s Azimuth:     30.1°    Central Duration = 06m53s 

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Predictions

The solar eclipse predictions were made using the VSOP87/ELP2000-82 solar and lunar ephemerides. The resulting Besselian elements from these ephemerides were originally generated for the NASA technical publication Five Millennium Canon of Solar Eclipses: -1999 to +3000.

The accuracy of the northern and southern edges of the eclipse path are limited to approximately 1-2 kilometers due to the lunar limb profile. For eclipses five centuries or more centuries in the past or future, the largest uncertainty in the predictions is caused by fluctuations in Earth's rotation due primarily to the tidal friction of the Moon. The resultant drift in apparent clock time is expressed as ΔT and is is based on the work of Morrison and Stephenson [2004].

The Gregorian calendar is used for all dates from 1582 Oct 15 onwards. Before that date, the Julian calendar is used (see Calendar Dates).


Acknowledgments

Besselian elements page formatting by Bill Kramer.

Eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. The information presented here is based on the Five Millennium Canon of Solar Eclipses: -1999 to +3000 (2000 BCE to 3000 CE).

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

"Eclipse Predictions by Fred Espenak, NASA's GSFC"

For more information, see: NASA Copyright Information

2023 Oct 30