The following table contains the Besselian elements for the Total Solar Eclipse of 2017 Aug 21 .
The geographic coordinates of the eclipse path are 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.) (=18:13:12.5 UT)
Ecliptic Conjunction: 18:31:19.4 TDT J.D. = 2457987.271753
(Sun & Moon in Ec. Lo.) (=18:30:09.1 UT)
Instant of 18:26:40.2 TDT J.D. = 2457987.268521
Greatest Eclipse: (=18:25:29.9 UT)
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Gamma = 0.4367 Ephemerides = VSOP87/ELP2000-82
Eclipse Magnitude = 1.0306 Lunation No. = 218
ΔT = 70.3 s Saros Series = 145 (22/77)
Lunar Radius k1 = 0.272488 (Penumbra) Shift in Δb = 0.00"
Constants: k2 = 0.272281 (Umbra) Lunar Position: Δl = 0.00"
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Geocentric Coordinates of Sun & Moon at Greatest Eclipse (VSOP87/ELP2000-82):
Sun: R.A. = 10h04m03.9s Moon: R.A. = 10h04m30.6s
Dec. =+11°51'42.9" 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"
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Polynomial Besselian Elements for: 2017 Aug 21 18:00:00.0 TDT (=t0)
n x y d l1 l2 μ
0 -0.129571 0.485416 11.86696 0.542093 -0.004025 89.24543
1 0.5406426 -0.1416400 -0.013622 0.0001241 0.0001234 15.003937
2 -0.0000294 -0.0000905 -0.000002 -0.0000118 -0.0000117
3 -0.0000081 0.0000020
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.
Predictions for the Total Solar Eclipse of 2017 Aug 21 were generated using the VSOP87/ELP2000-82 solar and lunar ephemerides and a value of ΔT = 70.3 seconds. 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.
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
