Total Lunar Eclipse of 1917 Jul 04

Fred Espenak

Key to Lunar Eclipse Figure (below)

Introduction

The Total Lunar Eclipse of 1917 Jul 04 is visible from the following geographic regions:

  • South America, Europe, Africa, South Asia, Australia

The diagram to the right depicts the Moon's path with respect to Earth's umbral and penumbral shadows. Below it is a map showing the geographic regions of eclipse visibility. Click on the figure to enlarge it. For an explanation of the features appearing in the figure, see Key to Lunar Eclipse Figures.

The instant of greatest eclipse takes place on 1917 Jul 04 at 21:39:04 TD (21:38:44 UT1). This is 1.7 days before the Moon reaches perigee. During the eclipse, the Moon is in the constellation Sagittarius. The synodic month in which the eclipse takes place has a Brown Lunation Number of -68.

The eclipse belongs to Saros 128 and is number 35 of 71 eclipses in the series. All eclipses in this series occur at the Moon’s ascending node. The Moon moves southward with respect to the node with each succeeding eclipse in the series and gamma decreases.

This total eclipse is central meaning the Moon’s disk actually passes through the axis of Earth’s umbral shadow. It has an umbral eclipse magnitude of 1.6185, and Gamma has a value of 0.1419. Because they are so deep, such eclipses typically have the longest total phases. In this case, the duration of totality lasts 96.0 minutes.

The total lunar eclipse of 1917 Jul 04 is preceded two weeks earlier by a partial solar eclipse on 1917 Jun 19, and it is followed two weeks later by a partial solar eclipse on 1917 Jul 19.

These eclipses all take place during a single eclipse season.

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., TD = UT1 + ΔT). ΔT has a value of 19.7 seconds for this eclipse.

The following links provide maps and data for the eclipse.

The tables below contain detailed predictions and additional information on the Total Lunar Eclipse of 1917 Jul 04 .

Eclipse Data: Total Lunar Eclipse of 1917 Jul 04

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 2.57618
Umbral Magnitude 1.61847
Gamma 0.14194
Epsilon 0.1426°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1917 Jul 04 at 21:39:03.7 TD (21:38:43.9 UT1) 2421414.401898
Ecliptic Opposition 1917 Jul 04 at 21:40:32.2 TD (21:40:12.5 UT1) 2421414.402922
Equatorial Opposition 1917 Jul 04 at 21:41:56.2 TD (21:41:36.4 UT1) 2421414.403894
Geocentric Coordinates of Sun and Moon
1917 Jul 04 at 21:39:03.7 TD (21:38:43.9 UT1)
Coordinate Sun Moon
Right Ascension06h53m26.6s18h53m19.5s
Declination+22°52'54.4"-22°44'30.4"
Semi-Diameter 15'43.9" 16'25.5"
Eq. Hor. Parallax 08.6" 1°00'17.0"
Geocentric Libration of Moon
Angle Value
l -3.3°
b -0.1°
c -3.7°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2794°
Umbral Radius 0.7550°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE405
ΔT 19.7 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 128 (35/71)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Total Lunar Eclipse of 1917 Jul 04

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD		 Time
UT1		 Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP118:57:30.918:57:11.223°02.1'S075°03.9'E 264.4° 1.5520°
Partial BeginsU119:52:40.919:52:21.222°56.2'S061°50.3'E 267.1° 1.0280°
Total BeginsU220:51:04.520:50:44.722°49.8'S047°50.3'E 276.3° 0.4810°
Greatest EclipseGreatest21:39:03.721:38:43.922°44.5'S036°19.9'E 349.1° 0.1426°
Total EndsU322:27:03.822:26:44.122°39.1'S024°49.3'E 61.8° 0.4814°
Partial EndsU423:25:28.023:25:08.222°32.3'S010°49.1'E 71.1° 1.0295°
Penumbral EndsP400:20:32.600:20:12.922°25.8'S002°23.4'W 73.8° 1.5542°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)05h23m01.7s
Partial (U4 - U1)03h32m47.1s
Total (U3 - U2)01h35m59.3s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Total Lunar Eclipse of 1917 Jul 04

Polynomial Besselian Elements
1917 Jul 04 at 22:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 0.16986 0.17804 0.3993 1.27946 0.75510 0.27379
1 0.56424 0.10905 -0.0001 0.00032 0.00032 0.00009
2 0.00015 0.00019 0.0000 -0.00000 -0.00000 -0.00000
3 -0.00001 -0.00000 - - - -

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

x = x0 + x1*t + x2*t2 + x3*t3 (or x = Σ [xn*tn]; n = 0 to 3)

where: t = t1 - t0 (decimal hours) and t0 = 22.000

Explanation of Besselian Elements

Eclipse Publications

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For more visit: AstroPixels Publishing


Links for the Total Lunar Eclipse of 1917 Jul 04

Links to Additional Lunar Eclipse Information

• Decade Tables of Lunar Eclipses:
| 1901 - 1910 | 1911 - 1919 | 1921 - 1930 | 1931 - 1940 | 1941 - 1950 |
| 1951 - 1960 | 1961 - 1970 | 1971 - 1980 | 1981 - 1990 | 1991 - 2000 |
| 2001 - 2010 | 2011 - 2020 | 2021 - 2030 | 2031 - 2040 | 2041 - 2050 |
| 2051 - 2060 | 2061 - 2070 | 2071 - 2080 | 2081 - 2090 | 2091 - 2100 |

Lunar Eclipse Publications

Eclipse Predictions

Predictions for the Total Lunar Eclipse of 1917 Jul 04 were generated using the JPL DE405 solar and lunar ephemerides. The lunar coordinates were calculated with respect to the Moon's Center of Mass.

The Earth's umbral and penumbral shadows were calculated using the Danjon methodusing a mean mid-latitude ellipticity to compensate for the opacity of the terrestrial atmosphere.

The 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). ΔT has a value of 19.7 seconds for this eclipse.

Acknowledgments

Some of the content on this web site is based on the book 21st Century Canon of Lunar Eclipses. All eclipse calculations are by Fred Espenak, and he assumes full responsibility for their accuracy.

Permission is granted to reproduce eclipse data when accompanied by a link to this page and an acknowledgment:

"Eclipse Predictions by Fred Espenak, www.EclipseWise.com"

The use of diagrams and maps is permitted provided that they are NOT altered (except for re-sizing) and the embedded credit line is NOT removed or covered.