Solar Eclipse Prime Page

Partial Solar Eclipse of 2025 Sep 21

Fred Espenak

Introduction


The Partial Solar Eclipse of 2025 Sep 21 is visible from the following geographic regions:

  • Partial Eclipse: south Pacific, New Zealand, Antarctica

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 2025 Sep 21 at 19:43:04 TD (19:41:52 UT1). This is 4.6 days before the Moon reaches apogee. During the eclipse, the Sun is in the constellation Virgo. The synodic month in which the eclipse takes place has a Brown Lunation Number of 1271.

The eclipse belongs to Saros 154 and is number 7 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.

This is a very deep partial eclipse. It has an eclipse magnitude of 0.8550, while Gamma has a value of -1.0651.

The partial solar eclipse of 2025 Sep 21 is preceded two weeks earlier by a total lunar eclipse on 2025 Sep 07.

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 71.9 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 Partial Solar Eclipse of 2025 Sep 21 .


Eclipse Data: Partial Solar Eclipse of 2025 Sep 21

Eclipse Characteristics
Parameter Value
Eclipse Magnitude 0.85504
Eclipse Obscuration 0.79691
Gamma-1.06509
Conjunction Times
Event Calendar Date & Time Julian Date
Greatest Eclipse 2025 Sep 21 at 19:43:04.2 TD (19:41:52.3 UT1) 2460940.320744
Ecliptic Conjunction 2025 Sep 21 at 19:55:17.4 TD (19:54:05.5 UT1) 2460940.329231
Equatorial Conjunction 2025 Sep 21 at 20:51:38.8 TD (20:50:26.9 UT1) 2460940.368367
Geocentric Coordinates of Sun and Moon
2025 Sep 21 at 19:43:04.2 TD (19:41:52.3 UT1)
Coordinate Sun Moon
Right Ascension11h56m36.9s11h54m42.8s
Declination+00°22'00.7"-00°29'14.7"
Semi-Diameter 15'55.9" 15'02.8"
Eq. Hor. Parallax 08.8" 0°55'13.2"
Geocentric Libration of Moon
Angle Value
l 4.2°
b 1.3°
c 21.9°
Prediction Paramaters
Paramater Value
Ephemerides JPL DE406
ΔT 71.9 s
k (penumbra) 0.2725076
k (umbra) 0.2722810
Saros Series 154 ( 7/71)

Explanation of Solar Eclipse Data Tables

Penumbral Shadow Contacts and Extremes: Partial Solar Eclipse of 2025 Sep 21

Contacts of Penumbral Shadow with Earth
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
First External ContactP117:30:51.317:29:39.413°58.3'S174°05.0'W
Last External ContactP421:54:55.121:53:43.272°16.0'S061°16.1'W
Extreme Northern and Southern Path Limits of Penumbra
Contact Event Contact Time
TD
Time
UT1
Latitude Longitude
North Extreme Path Limit 1N118:03:05.918:01:54.001°05.3'S177°49.5'E
South Extreme Path Limit 1S121:22:43.021:21:31.159°30.1'S052°44.9'W

Explanation of Penumbral Shadow Contacts and Extremes Tables

Polynomial Besselian Elements: Partial Solar Eclipse of 2025 Sep 21

Polynomial Besselian Elements
2025 Sep 21 at 20:00:00.0 TD (=t0)
n x y d l1 l2 μ
0 -0.39007 -1.00183 0.3647 0.56251 0.01627 121.7819
1 0.45316 -0.25216 -0.0156 0.00009 0.00009 15.0048
2 0.00000 0.00005 -0.0000 -0.00001 -0.00001 -0.0000
3 -0.00001 0.00000 - - - -
Tan ƒ1 0.0046583
Tan ƒ2 0.0046351

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 Polynomial Besselian Elements

Links for the Partial Solar Eclipse of 2025 Sep 21

Links to Additional Solar Eclipse Information

Eclipse Predictions

Predictions for the Partial Solar Eclipse of 2025 Sep 21 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 71.9 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.