Total Lunar Eclipse of 1921 Apr 22

Fred Espenak

Key to Lunar Eclipse Figure (below)

Introduction

The Total Lunar Eclipse of 1921 Apr 22 is visible from the following geographic regions:

  • Australia, Americas, western Europe, western Africa

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 1921 Apr 22 at 07:44:39 TD (07:44:17 UT1). This is 5.7 days after the Moon reaches perigee. During the eclipse, the Moon is in the constellation Virgo. The synodic month in which the eclipse takes place has a Brown Lunation Number of -21.

The eclipse belongs to Saros 130 and is number 29 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 is a very shallow total eclipse. It has an umbral eclipse magnitude of only 1.0678 and a duration of totality lasting 40.1 minutes. Gamma has a value of 0.4269.

The total lunar eclipse of 1921 Apr 22 is preceded two weeks earlier by a annular solar eclipse on 1921 Apr 08.

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 22.2 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 1921 Apr 22 .

Eclipse Data: Total Lunar Eclipse of 1921 Apr 22

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 2.08154
Umbral Magnitude 1.06782
Gamma 0.42693
Epsilon 0.4097°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1921 Apr 22 at 07:44:39.0 TD (07:44:16.8 UT1) 2422801.822417
Ecliptic Opposition 1921 Apr 22 at 07:49:20.4 TD (07:48:58.3 UT1) 2422801.825675
Equatorial Opposition 1921 Apr 22 at 07:32:22.0 TD (07:31:59.8 UT1) 2422801.813886
Geocentric Coordinates of Sun and Moon
1921 Apr 22 at 07:44:39.0 TD (07:44:16.8 UT1)
Coordinate Sun Moon
Right Ascension01h57m53.3s13h58m18.6s
Declination+12°02'44.0"-11°38'56.5"
Semi-Diameter 15'54.4" 15'41.5"
Eq. Hor. Parallax 08.7" 0°57'35.3"
Geocentric Libration of Moon
Angle Value
l 4.7°
b -0.5°
c 21.8°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2369°
Umbral Radius 0.7067°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE405
ΔT 22.2 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 130 (29/71)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Total Lunar Eclipse of 1921 Apr 22

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD		 Time
UT1		 Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP104:58:40.804:58:18.611°14.6'S076°14.5'W 300.5° 1.4999°
Partial BeginsU106:03:35.006:03:12.811°24.2'S091°54.8'W 309.6° 0.9691°
Total BeginsU207:24:34.107:24:11.911°36.0'S111°28.0'W 351.5° 0.4453°
Greatest EclipseGreatest07:44:39.007:44:16.811°38.9'S116°19.0'W 14.6° 0.4097°
Total EndsU308:04:40.708:04:18.611°41.8'S121°09.1'W 37.6° 0.4451°
Partial EndsU409:25:38.909:25:16.711°53.5'S140°42.2'W 79.5° 0.9673°
Penumbral EndsP410:30:41.510:30:19.412°02.8'S156°24.5'W 88.7° 1.4970°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)05h32m00.8s
Partial (U4 - U1)03h22m03.9s
Total (U3 - U2)00h40m06.7s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Total Lunar Eclipse of 1921 Apr 22

Polynomial Besselian Elements
1921 Apr 22 at 08:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 0.23219 0.36293 0.2103 1.23683 0.70661 0.26149
1 0.50404 -0.13119 0.0002 -0.00042 -0.00042 -0.00011
2 -0.00023 0.00012 -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 = 8.000

Explanation of Besselian Elements

Eclipse Publications

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For more visit: AstroPixels Publishing


Links for the Total Lunar Eclipse of 1921 Apr 22

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 1921 Apr 22 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 22.2 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.