Partial Lunar Eclipse of 1731 Dec 13

Fred Espenak

Introduction


The Partial Lunar Eclipse of 1731 Dec 13 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 1731 Dec 13 at 11:38:05 TD (11:37:55 UT1). This is 6.4 days before the Moon reaches apogee. During the eclipse, the Moon is in the constellation Taurus. The synodic month in which the eclipse takes place has a Brown Lunation Number of -2363.

The eclipse belongs to Saros 111 and is number 51 of 71 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 partial lunar eclipse of 1731 Dec 13 is followed two weeks later by a hybrid solar eclipse on 1731 Dec 29.

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 10.6 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 Partial Lunar Eclipse of 1731 Dec 13 .


Eclipse Data: Partial Lunar Eclipse of 1731 Dec 13

Eclipse Characteristics
Parameter Value
Penumbral Magnitude 1.46010
Umbral Magnitude 0.40694
Gamma 0.77647
Epsilon 0.7330°
Opposition Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1731 Dec 13 at 11:38:05.4 TD (11:37:54.8 UT1) 2353640.984662
Ecliptic Opposition 1731 Dec 13 at 11:29:22.5 TD (11:29:11.9 UT1) 2353640.978610
Equatorial Opposition 1731 Dec 13 at 11:35:18.9 TD (11:35:08.3 UT1) 2353640.982735
Geocentric Coordinates of Sun and Moon
1731 Dec 13 at 11:38:05.4 TD (11:37:54.8 UT1)
Coordinate Sun Moon
Right Ascension17h21m06.4s05h21m12.5s
Declination-23°10'21.3"+23°54'18.8"
Semi-Diameter 16'15.3" 15'26.1"
Eq. Hor. Parallax 08.9" 0°56'38.8"
Geocentric Libration of Moon
Angle Value
l 5.0°
b -0.9°
c -5.4°
Earth's Shadows
Parameter Value
Penumbral Radius 1.2270°
Umbral Radius 0.6851°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE406
ΔT 10.6 s
Shadow Rule Danjon
Shadow Enlargement 1.010
Saros Series 111 (51/71)

Explanation of Lunar Eclipse Data Tables

Eclipse Contacts: Partial Lunar Eclipse of 1731 Dec 13

Lunar Eclipse Contacts
Eclipse Event Contact Time
TD
Time
UT1
Zenith Latitude Zenith Longitude Position Angle Axis Distance
Penumbral BeginsP109:03:37.809:03:27.223°55.9'N138°37.0'W 301.3° 1.4855°
Partial BeginsU110:27:08.210:26:57.623°55.1'N158°43.3'W 322.8° 0.9429°
Greatest EclipseGreatest11:38:05.411:37:54.823°54.3'N175°48.3'W 1.8° 0.7330°
Partial EndsU412:48:53.712:48:43.123°53.3'N167°08.8'E 40.7° 0.9418°
Penumbral EndsP414:12:33.214:12:22.623°51.8'N147°00.1'E 62.2° 1.4829°
Eclipse Durations
Eclipse Phase Duration
Penumbral (P4 - P1)05h08m55.4s
Partial (U4 - U1)02h21m45.5s

Explanation of Lunar Eclipse Contacts Table

Polynomial Besselian Elements: Partial Lunar Eclipse of 1731 Dec 13

Polynomial Besselian Elements
1731 Dec 13 at 12:00:00.0 TD (=t0)
n x y d f1 f2 f3
0 0.20626 0.72680 -0.4045 1.22682 0.68497 0.25721
1 0.50123 -0.01601 -0.0000 -0.00039 -0.00039 -0.00010
2 -0.00023 -0.00019 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 = 12.000

Explanation of Besselian Elements

Links for the Partial Lunar Eclipse of 1731 Dec 13

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 Partial Lunar Eclipse of 1731 Dec 13 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 10.6 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.