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Besseliam Elements for the Total Solar Eclipse of 2017 Aug 21

Fred Espenak

The following table contains the Besseliam elements for the Total Solar Eclipse of 2017 Aug 21 .

The geographic coordinates of the eclipse path are listed in the Path Table . The global visibility of the eclipse is shown on an Orthographic Map . The features of this map are described in the Key to Solar Eclipse Path Tables. The path of the eclipse is displayed in greater detail on a Google Map .


            

Besselian Elements for the Total Solar Eclipse of 2017 Aug 21

Equatorial Conjunction: 18:14:22.8 TDT J.D. = 2457987.259986 (Sun & Moon in R.A.) (=18:13:14.4 UT) Ecliptic Conjunction: 18:31:19.6 TDT J.D. = 2457987.271754 (Sun & Moon in Ec. Lo.) (=18:30:11.2 UT) Instant of 18:26:40.3 TDT J.D. = 2457987.268521 Greatest Eclipse: (=18:25:31.8 UT) --------------------------------------------------------------------------- Gamma = 0.4367 Ephemerides = JPL DE405 Eclipse Magnitude = 1.0306 Lunation No. = 218 ΔT = 68.4 s Saros Series = 145 (22/77) Lunar Radius k1 = 0.272508 (Penumbra) Shift in Δb = 0.00" Constants: k2 = 0.272281 (Umbra) Lunar Position: Δl = 0.00" --------------------------------------------------------------------------- Geocentric Coordinates of Sun & Moon at Greatest Eclipse (JPL DE405): Sun: R.A. = 10h04m03.9s Moon: R.A. = 10h04m30.6s Dec. =+11°51'43.0" Dec. =+12°16'32.8" Semi-Diameter = 15'48.7" Semi-Diameter = 16'03.4" Eq.Hor.Par. = 08.7" Eq.Hor.Par. = 0°58'55.7" --------------------------------------------------------------------------- Polynomial Besselian Elements for: 2017 Aug 21 18:00:00.0 TDT (=t0) n x y d l1 l2 μ 0 -0.129576 0.485417 11.86697 0.542112 -0.004025 89.24545 1 0.5406409 -0.1416394 -0.013622 0.0001241 0.0001235 15.003937 2 -0.0000293 -0.0000905 -0.000002 -0.0000118 -0.0000117 3 -0.0000081 0.0000021 Tan ƒ1 = 0.0046222 Tan ƒ2 = 0.0045992 At time t1 (decimal hours), each Besselian element is evaluated by: a = a0 + a1*t + a2*t^2 + a3*t^3 (or a = Σ [an*t^n]; n = 0 to 3) where: a = x, y, d, l1, l2, or μ t = t1 - t0 (decimal hours) and t0 = 18.000 TDT The Besselian elements were derived from a least-squares fit to elements calculated at five uniformly spaced times over a six hour period centered at t0. The Besselian elements are valid over the period 15.00 ≤ t0 ≤ 21.00 TDT. Note that all times are expressed in Terrestrial Dynamical Time (TDT). Saros Series 145: Member 22 of 77 eclipses in series.

   Instant of 
Greatest Eclipse:       Time =  18:25:31.8 UT       Lat = 36°58.0'N      Long = 087°40.3'W
      (GE)               Sun Altitude =  63.9°          Path Width = 114.7 km
                          Sun Azimuth = 197.9°    Central Duration =   02m40.1s


   Instant of 
Greatest Duration:      Time =    18:21:49 UT       Lat =   37°35'N      Long =   089°07'W
      (GD)               Sun Altitude =  63.8°          Path Width = 114.5 km
                          Sun Azimuth = 192.5°    Central Duration =   02m40.3s


Additional Links: Total Solar Eclipse of 2017 Aug 21


Eclipse Predictions

Predictions for the Total Solar Eclipse of 2017 Aug 21 were generated using the JPL DE405 solar and lunar ephemerides and a value of ΔT = 68.4 seconds.

Acknowledgments

All eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy. 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


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