Penumbral Lunar Eclipse of 1999 Jan 31

Fred Espenak

Introduction


The Penumbral Lunar Eclipse of 1999 Jan 31 is visible from the following geographic regions:

  • Europe, Africa, Asia, Australia, Pacific

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 1999 Jan 31 at 16:18:34 TD (16:17:31 UT1). This is 4.8 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 941.

The eclipse belongs to Saros 114 and is number 58 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 very deep penumbral eclipse is a rare total penumbral eclipse in which the entire disk of the Moon is immersed in the penumbral shadow. It has a penumbral eclipse magnitude of 1.0027 and a penumbral eclipse duration of 261.8 minutes. Gamma has a value of -1.0190.

The penumbral lunar eclipse of 1999 Jan 31 is followed two weeks later by a annular solar eclipse on 1999 Feb 16.

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 63.5 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 1999 Jan 31 .


Eclipse Data: Penumbral Lunar Eclipse of 1999 Jan 31

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 1.00272
Umbral Magnitude-0.02583
Gamma-1.01898
Epsilon 0.9836°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1999 Jan 31 at 16:18:34.3 TD (16:17:30.8 UT1) 2451210.178829
Ecliptic Opposition 1999 Jan 31 at 16:07:34.4 TD (16:06:31.0 UT1) 2451210.171192
Equatorial Opposition 1999 Jan 31 at 16:39:08.1 TD (16:38:04.6 UT1) 2451210.193109
Geocentric Coordinates of Sun and Moon
1999 Jan 31 at 16:18:34.3 TD (16:17:30.8 UT1)
Coordinate Sun Moon
Right Ascension20h55m10.7s08h54m26.3s
Declination-17°22'34.0"+16°24'30.3"
Semi-Diameter 16'14.0" 15'47.0"
Eq. Hor. Parallax 08.9" 0°57'55.6"
Geocentric Libration of Moon
Angle Value
l 4.9°
b 1.3°
c 17.4°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2481°
Umbral Radius 0.7070°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE406
ΔT 63.5 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 114 (58/71)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Penumbral Lunar Eclipse of 1999 Jan 31

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD
Time
UT1
Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP114:07:38.414:06:34.916°38.2'N150°20.2'E 239.8° 1.5123°
Greatest EclipseGreatest16:18:34.316:17:30.816°24.5'N118°47.2'E 190.4° 0.9836°
Penumbral EndsP418:29:25.018:28:21.516°10.4'N087°15.1'E 141.0° 1.5100°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)04h21m46.6s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Penumbral Lunar Eclipse of 1999 Jan 31

Polynomial Besselian Elements
1999 Jan 31 at 16:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 -0.33734 -0.93823 -0.3033 1.24826 0.70713 0.26309
1 0.51736 -0.09472 0.0002 -0.00042 -0.00042 -0.00011
2 -0.00024 -0.00002 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 = 16.000

Explanation of Besselian Elements

Links for the Penumbral Lunar Eclipse of 1999 Jan 31

Links to Additional Lunar Eclipse Information

Eclipse Predictions

Predictions for the Penumbral Lunar Eclipse of 1999 Jan 31 were generated using the JPL DE406 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 63.5 seconds for this eclipse.

Acknowledgments

Some of the content on this web site is based on the book Thousand Year Canon of Lunar 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 covered.