Partial Lunar Eclipse of 1977 Apr 04

Fred Espenak

Introduction

The Partial Lunar Eclipse of 1977 Apr 04 is visible from the following geographic regions:

Americas, Europe, 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 1977 Apr 04 at 04:19:03 TD (04:18:16 UT1). This is 1.7 days before 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 671.

The eclipse belongs to Saros 112 and is number 63 of 72 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.

The partial lunar eclipse of 1977 Apr 04 is followed two weeks later by a annular solar eclipse on 1977 Apr 18.

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 47.8 seconds for this eclipse.

The following links provide maps and data for the eclipse.

Detailed Lunar Eclipse Figure - eclipse geometry diagram and map of eclipse visibility (Key to Figure)
Saros 112 Table - data for all eclipses in the Saros series

The tables below contain detailed predictions and additional information on the Partial Lunar Eclipse of 1977 Apr 04 .

Eclipse Data: Partial Lunar Eclipse of 1977 Apr 04

Eclipse Characteristics
Parameter	Value
Penumbral Magnitude	1.16570
Umbral Magnitude	0.19289
Gamma	-0.91483
Epsilon	0.9197°

Opposition Times
Event	Calendar Date & Time	Julian Date
Greatest Eclipse	1977 Apr 04 at 04:19:03.5 TD (04:18:15.7 UT1)	2443237.679348
Ecliptic Opposition	1977 Apr 04 at 04:09:40.1 TD (04:08:52.3 UT1)	2443237.672827
Equatorial Opposition	1977 Apr 04 at 04:48:49.1 TD (04:48:01.3 UT1)	2443237.700015

Geocentric Coordinates of Sun and Moon
1977 Apr 04 at 04:19:03.5 TD (04:18:15.7 UT1)
Coordinate	Sun	Moon
Right Ascension	00h52m35.5s	12h51m29.8s
Declination	+05°37'56.4"	-06°30'38.9"
Semi-Diameter	15'59.4"	16'26.2"
Eq. Hor. Parallax	08.8"	1°00'19.6"

Geocentric Libration of Moon
Angle	Value
l	-3.4°
b	1.2°
c	24.3°

Earth's Shadows
Parameter	Value
Penumbral Radius	1.2844°
Umbral Radius	0.7514°

Prediction Paramaters
Paramater	Value
Ephemerides	JPL DE405
ΔT	47.8 s
Shadow Rule	Danjon
Shadow Enlargement	1.010
Saros Series	112 (63/72)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Partial Lunar Eclipse of 1977 Apr 04

Lunar Eclipse Contacts
Eclipse Event	Contact	Time TD	Time UT1	Zenith Latitude	Zenith Longitude	Position Angle	Axis Distance
Penumbral Begins	P1	02:07:35.6	02:06:47.8	06°06.1'S	032°23.9'W	251.0°	1.5575°
Partial Begins	U1	03:31:44.5	03:30:56.7	06°21.8'S	052°40.0'W	223.4°	1.0251°
Greatest Eclipse	Greatest	04:19:03.5	04:18:15.7	06°30.6'S	064°03.8'W	197.2°	0.9197°
Partial Ends	U4	05:06:30.1	05:05:42.3	06°39.5'S	075°29.4'W	170.9°	1.0257°
Penumbral Ends	P4	06:30:33.4	06:29:45.5	06°55.0'S	095°44.0'W	143.3°	1.5592°

Eclipse Durations
Eclipse Phase	Duration
Penumbral (P4 - P1)	04h22m57.7s
Partial (U4 - U1)	01h34m45.6s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Partial Lunar Eclipse of 1977 Apr 04

Polynomial Besselian Elements
1977 Apr 04 at 04:00:00.0 TD (=t0)
n	x	y	d	f1	f2	f3
0	-0.44638	-0.82452	0.0982	1.28433	0.75132	0.27393
1	0.54843	-0.16996	0.0003	0.00032	0.00032	0.00009
2	0.00022	0.00003	-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 = 4.000

Explanation of Besselian Elements

Eclipse Publications

For more visit: AstroPixels Publishing

Links for the Partial Lunar Eclipse of 1977 Apr 04

Detailed Lunar Eclipse Figure - eclipse geometry figure and map of eclipse visibility using Danjon method
Saros 112 Table - data for all eclipses in the Saros series
Partial Lunar Eclipse of 1977 Apr 04 - Google search for links to this eclipse

Links to Additional Lunar Eclipse Information

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

Lunar Eclipses - primary page for lunar eclipse predictions
Lunar Eclipse Links - detailed directory of links

• 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 |

Six Millennium Catalog of Lunar Eclipses - covers the years -2999 to +3000 (3000 BCE to 3000 CE)
Saros Catalog of Lunar Eclipses - covers Saros series -29 through 190
Javascript Lunar Eclipse Explorer - calculate all lunar eclipses visible from a city

Lunar Eclipse Basics - the fundamentals about lunar eclipses
Visual Appearance of Lunar Eclipses - describes how different types of lunar eclipses appear
Danjon Scale of Lunar Eclipse Brightness - evaluating the brightness of total lunar eclipses
Enlargement of Earth's Shadows (Herald and Sinnott method) - the effect on lunar eclipse predictions
Enlargement of Earth's Shadows (Danjon method) - the effect on lunar predictions

MrEclipse.com - Eclipse resources and tips on photography
MrEclipse: Lunar Eclipses for Beginners - a primer on solar eclipse basics
How to Photograph a Lunar Eclipse - instructions for imaging an eclipse of the Moon
MrEclipse Photo Index - an index of lunar eclipse photographs

Lunar Eclipse Publications

Eclipse Almanac: 2021 to 2030 - all solar and lunar eclipses for the decade
21st Century Canon of Lunar Eclipses - every lunar eclipse from 2001 through 2100
Thousand Year Canon of Lunar Eclipses 1501 to 2500 - basic details about every lunar eclipse for 1000 years
Five Millennium Canon of Lunar Eclipses: -1999 to +3000 - the ultimate reference with maps and diagrams
Five Millennium Catalog of Lunar Eclipses: -1999 to +3000 - the ultimate reference containing comprehensive tables

Eclipse Predictions

Predictions for the Partial Lunar Eclipse of 1977 Apr 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 47.8 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.