Eclipse listing, timing and the Saros series
Recent (11th August 2017) knowledge base article:
Eclipse listing for 2016-2018
How did I do this?
Load a Natal chart and tap Secondary Progressions, and then tap Bi-Wheel. Select a year: 2017. Next tap the eclipse button/icon. This allows AC to calculate the eclipses for 2017. Note all eclipse aspects are to the natal chart – the Eclipse listings will have a range approx 2016-2018. To see the aspects to the natal chart tap the Aspect button/icon.
Solar Eclipse for August 21st, 2017
Let’s look at the solar eclipse listing for August 21st, 2017, at 28Leo52. This is a total eclipse, and the Saros series is 145 The time of the maximum eclipse is at 6:25:34 UT (Universal Time)
This timing of the eclipse is from the site of Fred Espenak
|Event||Calendar Date & Time||Julian Date|
|Greatest Eclipse||2017 Aug 21 at 18:26:40.3 TD (18:25:31.7 UT1)||2457987.267728|
|Ecliptic Conjunction||2017 Aug 21 at 18:31:19.6 TD (18:30:11.0 UT1)||2457987.270961|
|Equatorial Conjunction||2017 Aug 21 at 18:14:22.8 TD (18:13:14.3 UT1)||2457987.259193|
UT time of the Greatest Eclipse is in Bold – my emphasis. Note many eclipse sites give the TD time (Terrestrial Dynamic) as 2017 Aug 21 at 18:26:40.3
To get the TD time from the given UT time as given by Fred Espenak:
The eclipse predictions are given in both Terrestrial Dynamical Time (TD) and Universal Time (UT1). The parameter ΔT is used to convert between these two times (i.e., UT1 = TD – ΔT). Δ Thas a value of 68.5 seconds for this eclipse.
So for the given UT time of 16:25:34 for the eclipse of Aug 21st 2017, add 68.5 seconds which gives 16:26:42