Solar Eclipse Prime Page

Total Solar Eclipse of 1981 Jul 31

Fred Espenak

Introduction


The Total Solar Eclipse of 1981 Jul 31 is visible from the following geographic regions:

  • Partial Eclipse: east Europe, Asia, Alaska, northwest Canada
  • Total Eclipse: Kazakhstan, Russia, north Pacific

The map to the right depicts the geographic regions of eclipse visibility. Click on the map to enlarge it. For an explanation of the features appearing in the map, see Key to Solar Eclipse Maps.

The instant of greatest eclipse takes place on 1981 Jul 31 at 03:46:37 TD (03:45:45 UT1). This is 3.8 days after the Moon reaches perigee. During the eclipse, the Sun is in the constellation Cancer. The synodic month in which the eclipse takes place has a Brown Lunation Number of 725.

The eclipse belongs to Saros 145 and is number 20 of 77 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 total solar eclipse of 1981 Jul 31 is preceded two weeks earlier by a partial lunar eclipse on 1981 Jul 17.

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 51.9 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 Total Solar Eclipse of 1981 Jul 31 .


Eclipse Data: Total Solar Eclipse of 1981 Jul 31

Eclipse Characteristics
Parameter Value
Eclipse Magnitude 1.02584
Eclipse Obscuration 1.05235
Gamma 0.57917
Conjunction Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 1981 Jul 31 at 03:46:36.6 TD (03:45:44.7 UT1) 2444816.656767
Ecliptic Conjunction 1981 Jul 31 at 03:52:48.9 TD (03:51:57.0 UT1) 2444816.661077
Equatorial Conjunction 1981 Jul 31 at 03:36:25.8 TD (03:35:33.9 UT1) 2444816.649698
Geocentric Coordinates of Sun and Moon
1981 Jul 31 at 03:46:36.6 TD (03:45:44.7 UT1)
Coordinate Sun Moon
Right Ascension08h41m03.3s08h41m26.2s
Declination+18°18'24.9"+18°51'47.8"
Semi-Diameter 15'45.4" 15'57.1"
Eq. Hor. Parallax 08.7" 0°58'32.6"
Geocentric Libration of Moon
Angle Value
l 4.8°
b -0.7°
c 16.4°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE406
ΔT 51.9 s
k (penumbra) 0.2725076
k (umbra) 0.2722810
Saros Series 145 (20/77)

Explanation of Solar Eclipse Data Tables

Penumbral Shadow Contacts and Extremes: Total Solar Eclipse of 1981 Jul 31

Contacts of Penumbral Shadow with Earth
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
First External ContactP101:12:08.001:11:16.129°39.4'N062°53.6'E
Last External ContactP406:21:15.506:20:23.612°11.2'N179°26.0'W
Extreme Northern and Southern Path Limits of Penumbra
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
North Extreme Path Limit 1N101:49:56.401:49:04.511°06.4'N060°35.2'E
South Extreme Path Limit 1S105:43:19.405:42:27.506°33.1'S176°12.8'W

Explanation of Penumbral Shadow Contacts and Extremes Tables

Umbral Shadow Contacts and Extremes: Total Solar Eclipse of 1981 Jul 31

Contacts of Umbral Shadow with Earth
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
First External ContactU102:18:14.002:17:22.141°53.8'N039°57.6'E
First Internal ContactU202:19:07.502:18:15.642°08.7'N039°34.8'E
Last Internal ContactU305:14:16.105:13:24.224°59.3'N157°54.7'W
Last External ContactU405:15:04.105:14:12.224°45.4'N158°12.3'W
Extreme Northern and Southern Path Limits of Umbra
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
North Extreme Path Limit 1N102:18:58.702:18:06.842°14.0'N039°33.7'E
South Extreme Path Limit 1S102:18:22.902:17:31.041°48.5'N039°58.7'E
North Extreme Path Limit 2N205:14:24.005:13:32.125°04.3'N157°54.6'W
South Extreme Path Limit 2S205:14:56.105:14:04.224°40.5'N158°12.4'W

Explanation of Umbral Shadow Contacts and Extremes Tables

Central Line Extremes and Duration: Total Solar Eclipse of 1981 Jul 31

Extreme Limits of the Central Line
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
Extreme Central Line Limit 1C102:18:40.702:17:48.842°01.3'N039°46.2'E
Extreme Central Line Limit 2C205:14:40.105:13:48.224°52.4'N158°03.5'W

Explanation of Central Line Extremes Table

Greatest Eclipse and Greatest Duration
Event Time
TD
Time
UT1
Latitude Longitude Sun
Altitude
Sun
Azimuth
Path Width Central
Duration
Greatest Eclipse03:46:36.603:45:44.753°17.0'N133°51.2'E 54.3° 194.6° 107.8 km02m02.38s
Greatest Duration03:43:31.503:42:39.653°41.2'N132°11.0'E 54.3° 190.2° 107.7 km02m02.46s

Explanation of Greatest Eclipse and Greatest Duration

Polynomial Besselian Elements: Total Solar Eclipse of 1981 Jul 31

Polynomial Besselian Elements
1981 Jul 31 at 04:00:00.0 TD (=t0)
n x y d l1 l2 μ
0 0.21525 0.55176 18.3033 0.54301 -0.00313 238.4211
1 0.54793 -0.08917 -0.0100 0.00011 0.00011 15.0019
2 -0.00005 -0.00014 -0.0000 -0.00001 -0.00001 0.0000
3 -0.00001 0.00000 - - - -
Tan ƒ1 0.0046061
Tan ƒ2 0.0045832

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 Polynomial Besselian Elements

Links for the Total Solar Eclipse of 1981 Jul 31

Links to Additional Solar Eclipse Information

Eclipse Predictions

Predictions for the Total Solar Eclipse of 1981 Jul 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 51.9 seconds for this eclipse.

Acknowledgments

Some of the content on this website is based on the book Thousand Year Canon of Solar 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.