Penumbral Lunar Eclipse of 0779 Aug 31

Fred Espenak

Introduction


The Penumbral Lunar Eclipse of 0779 Aug 31 is visible from the geographic regions shown on the map to the right. The diagram above the map depicts the Moon's path with respect to Earth's umbral and penumbral shadows. 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 0779 Aug 31 at 20:11:54 TD (19:20:13 UT1). This is 4.9 days after the Moon reaches apogee. During the eclipse, the Moon is in the constellation Pisces. The synodic month in which the eclipse takes place has a Brown Lunation Number of -14141.

The eclipse belongs to Saros 108 and is number 6 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 penumbral lunar eclipse of 0779 Aug 31 is preceded two weeks earlier by a total solar eclipse on 0779 Aug 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., UT1 = TD - ΔT). ΔT has a value of 3101.0 seconds for this eclipse. The uncertainty in ΔT is 86.6 seconds corresponding to a standard error in longitude of the eclipse visibility zones of 0.36°.

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 0779 Aug 31 .


Eclipse Data: Penumbral Lunar Eclipse of 0779 Aug 31

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 0.58814
Umbral Magnitude-0.46767
Gamma 1.25243
Epsilon 1.1569°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 0779 Aug 31 at 20:11:54.0 TD (19:20:13.0 UT1) 2005830.305706
Ecliptic Opposition 0779 Aug 31 at 20:26:02.2 TD (19:34:21.2 UT1) 2005830.315523
Equatorial Opposition 0779 Aug 31 at 21:28:54.3 TD (20:37:13.3 UT1) 2005830.359181
Geocentric Coordinates of Sun and Moon
0779 Aug 31 at 20:11:54.0 TD (19:20:13.0 UT1)
Coordinate Sun Moon
Right Ascension10h50m18.4s22h48m07.1s
Declination+07°27'09.6"-06°25'52.0"
Semi-Diameter 15'56.8" 15'06.2"
Eq. Hor. Parallax 08.8" 0°55'25.9"
Geocentric Libration of Moon
Angle Value
l -4.0°
b -1.5°
c -20.9°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2013°
Umbral Radius 0.6698°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE406
ΔT 3101.0 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 108 ( 6/72)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Penumbral Lunar Eclipse of 0779 Aug 31

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD
Time
UT1
Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP118:22:02.417:30:21.406°52.2'S095°39.7'E 294.8° 1.4523°
Greatest EclipseGreatest20:11:54.019:20:13.006°25.9'S068°58.3'E 332.0° 1.1569°
Penumbral EndsP422:01:55.021:10:14.005°59.3'S042°14.6'E 9.2° 1.4538°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)03h39m52.6s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Penumbral Lunar Eclipse of 0779 Aug 31

Polynomial Besselian Elements
0779 Aug 31 at 20:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 -0.62778 0.97644 0.1301 1.20125 0.66969 0.25171
1 0.42345 0.22550 -0.0003 0.00031 0.00031 0.00008
2 0.00016 0.00008 -0.0000 0.00000 0.00000 0.00000
3 -0.00000 -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 = 20.000

Explanation of Besselian Elements

Links for the Penumbral Lunar Eclipse of 0779 Aug 31

Links to Additional Lunar Eclipse Information

Calendar

The Gregorian calendar (also called the Western calendar) is internationally the most widely used civil calendar. It is named for Pope Gregory XIII, who introduced it in 1582. On this website, the Gregorian calendar is used for all calendar dates from 1582 Oct 15 onwards. Before that date, the Julian calendar is used. For more information on this topic, see Calendar Dates.

The Julian calendar does not include the year 0. Thus the year 1 BCE is followed by the year 1 CE (See: BCE/CE Dating Conventions). This is awkward for arithmetic calculations. Years in this catalog are numbered astronomically and include the year 0. Historians should note there is a difference of one year between astronomical dates and BCE dates. Thus, the astronomical year 0 corresponds to 1 BCE, and astronomical year -1 corresponds to 2 BCE, etc..

Eclipse Predictions

Predictions for the Penumbral Lunar Eclipse of 0779 Aug 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 3101.0 seconds for this eclipse. The uncertainty in ΔT is 86.6 seconds corresponding to a standard error in longitude of the eclipse visibility zones of 0.36°.

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.