Penumbral Lunar Eclipse of 1991 Jan 30

Fred Espenak

Key to Lunar Eclipse Figure (below)

Introduction

The Penumbral Lunar Eclipse of 1991 Jan 30 is visible from the following geographic regions:

  • Americas, 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 1991 Jan 30 at 05:59:37 TD (05:58:40 UT1). This is 1.9 days after the Moon reaches perigee. During the eclipse, the Moon is in the constellation Cancer. The synodic month in which the eclipse takes place has a Brown Lunation Number of 842.

The eclipse belongs to Saros 143 and is number 16 of 72 eclipses in the series. All eclipses in this series occur at the Moon’s descending node. The Moon moves northward with respect to the node with each succeeding eclipse in the series and gamma increases.

The penumbral lunar eclipse of 1991 Jan 30 is preceded two weeks earlier by a annular solar eclipse on 1991 Jan 15.

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 57.6 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 Penumbral Lunar Eclipse of 1991 Jan 30 .

Eclipse Data: Penumbral Lunar Eclipse of 1991 Jan 30

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 0.88079
Umbral Magnitude-0.11060
Gamma-1.07522
Epsilon 1.0770°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1991 Jan 30 at 05:59:37.3 TD (05:58:39.7 UT1) 2448286.749070
Ecliptic Opposition 1991 Jan 30 at 06:10:40.5 TD (06:09:42.9 UT1) 2448286.756747
Equatorial Opposition 1991 Jan 30 at 06:43:26.9 TD (06:42:29.3 UT1) 2448286.779506
Geocentric Coordinates of Sun and Moon
1991 Jan 30 at 05:59:37.3 TD (05:58:39.7 UT1)
Coordinate Sun Moon
Right Ascension20h49m07.1s08h47m30.0s
Declination-17°47'12.6"+16°46'53.1"
Semi-Diameter 16'14.2" 16'22.7"
Eq. Hor. Parallax 08.9" 1°00'06.5"
Geocentric Libration of Moon
Angle Value
l 3.4°
b 1.4°
c 13.9°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2849°
Umbral Radius 0.7437°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE405
ΔT 57.6 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 143 (16/72)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Penumbral Lunar Eclipse of 1991 Jan 30

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD		 Time
UT1		 Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP104:00:48.103:59:50.517°12.2'N058°09.9'W 247.4° 1.5587°
Greatest EclipseGreatest05:59:37.305:58:39.716°46.9'N086°45.9'W 201.1° 1.0770°
Penumbral EndsP407:58:21.607:57:24.016°21.2'N115°21.1'W 154.9° 1.5570°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)03h57m33.5s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Penumbral Lunar Eclipse of 1991 Jan 30

Polynomial Besselian Elements
1991 Jan 30 at 06:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 -0.38400 -1.00625 -0.3104 1.28491 0.74368 0.27296
1 0.53045 -0.20445 0.0002 -0.00034 -0.00034 -0.00009
2 -0.00022 0.00001 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 = 6.000

Explanation of Besselian Elements

Eclipse Publications

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For more visit: AstroPixels Publishing


Links for the Penumbral Lunar Eclipse of 1991 Jan 30

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 Penumbral Lunar Eclipse of 1991 Jan 30 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 57.6 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.