Solar Eclipse Prime Page

Partial Solar Eclipse of 1931 Apr 18

Fred Espenak

Key to Solar Eclipse Figure (below)

Introduction


The Partial Solar Eclipse of 1931 Apr 18 is visible from the following geographic regions:

  • Partial Eclipse: east Asia, north Canada, Greenland

The map to the right depicts the geographic regions of eclipse visibility. Click on the map to enlarge it. For an explanation of the features appearing in the map, see Key to Solar Eclipse Maps.

The instant of greatest eclipse takes place on 1931 Apr 18 at 00:45:35 TD (00:45:11 UT1). This is 3.7 days after the Moon reaches apogee. During the eclipse, the Sun is in the constellation Aries. The synodic month in which the eclipse takes place has a Brown Lunation Number of 103.

The eclipse belongs to Saros 147 and is number 18 of 80 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 is a very deep partial eclipse. It has an eclipse magnitude of 0.5107, while Gamma has a value of 1.2643.

The partial solar eclipse of 1931 Apr 18 is preceded two weeks earlier by a total lunar eclipse on 1931 Apr 02.

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., UT1 = TD - ΔT). ΔT has a value of 24.0 seconds for this eclipse.

The following links provide maps and data for the eclipse.

Eclipse Data: Partial Solar Eclipse of 1931 Apr 18

Eclipse Characteristics
Parameter Value
Eclipse Magnitude 0.51068
Eclipse Obscuration 0.39455
Gamma 1.26430
Conjunction Times
Event Calendar Date and Time Julian Date
Greatest Eclipse 1931 Apr 18 at 00:45:34.6 TD (00:45:10.6 UT1) 2426449.531373
Ecliptic Conjunction 1931 Apr 18 at 00:59:58.6 TD (00:59:34.7 UT1) 2426449.541374
Equatorial Conjunction 1931 Apr 18 at 01:59:51.2 TD (01:59:27.3 UT1) 2426449.582954
Geocentric Coordinates of Sun and Moon
1931 Apr 18 at 00:45:34.6 TD (00:45:10.6 UT1)
Coordinate Sun Moon
Right Ascension01h40m20.1s01h38m13.6s
Declination+10°25'14.0"+11°26'51.3"
Semi-Diameter 15'55.6" 14'54.6"
Eq. Hor. Parallax 08.8" 0°54'43.2"
Geocentric Libration of Moon
Angle Value
l -3.6°
b -1.5°
c -19.7°
Prediction Parameters
Paramater Value
Ephemerides JPL DE405
ΔT 24.0 s
k (penumbra) 0.2725076
k (umbra) 0.2722810
Saros Series 147 (18/80)

Explanation of Solar Eclipse Data Tables

Penumbral Shadow Contacts and Extremes: Partial Solar Eclipse of 1931 Apr 18

Contacts of Penumbral Shadow with Earth
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
First External ContactP122:57:48.022:57:24.126°52.1'N100°14.0'E
Last External ContactP402:32:47.702:32:23.876°06.1'N080°03.0'W
Extreme Northern and Southern Path Limits of Penumbra
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
North Extreme Path Limit 1N123:17:54.223:17:30.317°34.1'N097°12.4'E
South Extreme Path Limit 1S102:12:40.602:12:16.768°46.4'N094°51.1'W

Explanation of Penumbral Shadow Contacts and Extremes Tables

Polynomial Besselian Elements: Partial Solar Eclipse of 1931 Apr 18

Polynomial Besselian Elements
1931 Apr 18 at 01:00:00.0 TD (=t0)
n x y d l1 l2 μ
0 -0.45759 1.18502 10.4212 0.56502 0.01877 195.0928
1 0.45866 0.23050 0.0141 -0.00008 -0.00008 15.0036
2 0.00006 -0.00010 -0.0000 -0.00001 -0.00001 -0.0000
3 -0.00001 -0.00000 - - - -
Tan ƒ1 0.0046571
Tan ƒ2 0.0046339

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 = 1.000

Explanation of Polynomial Besselian Elements

Eclipse Publications

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For more visit: AstroPixels Publishing

Links for the Partial Solar Eclipse of 1931 Apr 18

Links to Additional Solar Eclipse Information

  • Home - home page of EclipseWise with predictions for both solar and lunar eclipses

Decade Tables of Solar 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 |

Solar Eclipse Publications

Eclipse Publications

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jpeg jpeg
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For more visit: AstroPixels Publishing

Eclipse Predictions

Predictions for the Partial Solar Eclipse of 1931 Apr 18 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 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 24.0 seconds for this eclipse.

Acknowledgments

Some of the content on this website is based on the books 21st Century Canon of Solar Eclipses and Thousand Year Canon of Solar Eclipses 1501 to 2500. 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 concealed.