# September 1951 lunar eclipse

A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Saturday, September 15, 1951, with an umbral magnitude of −0.1927. A lunar eclipse occurs when the Moon moves into the Earth's shadow, causing the Moon to be darkened. A penumbral lunar eclipse occurs when part or all of the Moon's near side passes into the Earth's penumbra. Unlike a solar eclipse, which can only be viewed from a relatively small area of the world, a lunar eclipse may be viewed from anywhere on the night side of Earth. Occurring about 3.6 days after perigee (on September 11, 1951, at 21:30 UTC), the Moon's apparent diameter was larger.
This eclipse was the last of four penumbral lunar eclipses in 1951, with the others occurring on February 21, March 23, and August 17.

## Visibility

The eclipse was completely visible over east and northeast Asia, Australia, and northwestern North America, seen rising over central and south Asia and setting over much of North America and western South America.

## Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.
September 15, 1951 Lunar Eclipse Parameters :
| Parameter | Value |
| Penumbral Magnitude | 0.80351 |
| Umbral Magnitude | −0.19267 |
| Gamma | 1.11865 |
| Sun Right Ascension | 11h30m04.6s |
| Sun Declination | +03°13'56.1" |
| Sun Semi-Diameter | 15'54.4" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 23h27m58.3s |
| Moon Declination | -02°16'28.5" |
| Moon Semi-Diameter | 15'58.0" |
| Moon Equatorial Horizontal Parallax | 0°58'36.0" |
| ΔT | 29.8 s |

## Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two (or occasionally three) eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months (173 days) later; thus two full eclipse seasons always occur each year. Either two or three eclipses happen each eclipse season. In the sequence below, each eclipse is separated by a fortnight. The first and last eclipse in this sequence is separated by one synodic month.
Eclipse season of August–September 1951 :
| August 17 Ascending node (full moon) | September 1 Descending node (new moon) | September 15 Ascending node (full moon) |
| Penumbral lunar eclipse Lunar Saros 108 | Annular solar eclipse Solar Saros 134 | Penumbral lunar eclipse Lunar Saros 146 |

## Related eclipses
### Eclipses in 1951

* A penumbral lunar eclipse on February 21.
* An annular solar eclipse on March 7.
* A penumbral lunar eclipse on March 23.
* A penumbral lunar eclipse on August 17.
* An annular solar eclipse on September 1.
* A penumbral lunar eclipse on September 15.

### Metonic

* Preceded by: Lunar eclipse of November 28, 1947

### Tzolkinex

* Preceded by: Lunar eclipse of August 4, 1944
* Followed by: Lunar eclipse of October 27, 1958

### Half-Saros

* Preceded by: Solar eclipse of September 10, 1942
* Followed by: Solar eclipse of September 20, 1960

### Tritos

* Preceded by: Lunar eclipse of October 16, 1940
* Followed by: Lunar eclipse of August 15, 1962

### Lunar Saros 146

* Preceded by: Lunar eclipse of September 4, 1933
* Followed by: Lunar eclipse of September 25, 1969

### Inex

* Preceded by: Lunar eclipse of October 6, 1922
* Followed by: Lunar eclipse of August 26, 1980

### Triad

* Preceded by: Lunar eclipse of November 13, 1864
* Followed by: Lunar eclipse of July 16, 2038

### Lunar eclipses of 1948–1951

This eclipse is a member of a semester series. An eclipse in a semester series of lunar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.
The penumbral lunar eclipses on February 21, 1951 and August 17, 1951 occur in the next lunar year eclipse set.
Lunar eclipse series sets from 1948 to 1951 :
| Descending node | Descending node | Descending node | Descending node | Ascending node | Ascending node | Ascending node | Ascending node |
| Saros | Date Viewing | Type Chart | Gamma | Saros | Date Viewing | Type Chart | Gamma |
| 111 | 1948 Apr 23 | Partial | 1.0017 | 116 | 1948 Oct 18 | Penumbral | −1.0245 |
| 121 | 1949 Apr 13 | Total | 0.2474 | 126 | 1949 Oct 07 | Total | −0.3219 |
| 131 | 1950 Apr 02 | Total | −0.4599 | 136 | 1950 Sep 26 | Total | 0.4101 |
| 141 | 1951 Mar 23 | Penumbral | −1.2099 | 146 | 1951 Sep 15 | Penumbral | 1.1187 |

### Saros 146

This eclipse is a part of Saros series 146, repeating every 18 years, 11 days, and containing 72 events. The series started with a penumbral lunar eclipse on July 11, 1843. It contains partial eclipses from October 17, 2005 through May 14, 2348; total eclipses from May 25, 2366 through November 16, 2654; and a second set of partial eclipses from November 27, 2672 through June 12, 2997. The series ends at member 72 as a penumbral eclipse on August 29, 3123.
The longest duration of totality will be produced by member 37 at 99 minutes, 22 seconds on August 8, 2492. All eclipses in this series occur at the Moon’s ascending node of orbit.
| Greatest | First | First | First | First |
| The greatest eclipse of the series will occur on 2492 Aug 08, lasting 99 minutes, 22 seconds. | Penumbral | Partial | Total | Central |
| The greatest eclipse of the series will occur on 2492 Aug 08, lasting 99 minutes, 22 seconds. | 1843 Jul 11 | 2005 Oct 17 | 2366 May 25 | 2438 Jul 07 |
| Last ||||
| The greatest eclipse of the series will occur on 2492 Aug 08, lasting 99 minutes, 22 seconds. | Central | Total | Partial | Penumbral |
| The greatest eclipse of the series will occur on 2492 Aug 08, lasting 99 minutes, 22 seconds. | 2546 Sep 11 | 2654 Nov 16 | 2997 Jun 12 | 3123 Aug 29 |
Eclipses are tabulated in three columns; every third eclipse in the same column is one exeligmos apart, so they all cast shadows over approximately the same parts of the Earth.
Series members 1–20 occur between 1843 and 2200: :
| 1 | 1 | 2 | 2 | 3 | 3 |
| 1843 Jul 11 | 1843 Jul 11 | 1861 Jul 21 | 1861 Jul 21 | 1879 Aug 02 | 1879 Aug 02 |
| 4 | 4 | 5 | 5 | 6 | 6 |
| 1897 Aug 12 | 1897 Aug 12 | 1915 Aug 24 | 1915 Aug 24 | 1933 Sep 04 | 1933 Sep 04 |
| 7 | 7 | 8 | 8 | 9 | 9 |
| 1951 Sep 15 | 1951 Sep 15 | 1969 Sep 25 | 1969 Sep 25 | 1987 Oct 07 | 1987 Oct 07 |
| 10 | 10 | 11 | 11 | 12 | 12 |
| 2005 Oct 17 | 2005 Oct 17 | 2023 Oct 28 | 2023 Oct 28 | 2041 Nov 08 | 2041 Nov 08 |
| 13 | 13 | 14 | 14 | 15 | 15 |
| 2059 Nov 19 | 2059 Nov 19 | 2077 Nov 29 | 2077 Nov 29 | 2095 Dec 11 | 2095 Dec 11 |
| 16 | 16 | 17 | 17 | 18 | 18 |
| 2113 Dec 22 | 2113 Dec 22 | 2132 Jan 02 | 2132 Jan 02 | 2150 Jan 13 | 2150 Jan 13 |
| 19 | 19 | 20 | 20 |
| 2168 Jan 24 | 2168 Jan 24 | 2186 Feb 04 | 2186 Feb 04 |

### Tritos series

This eclipse is a part of a tritos cycle, repeating at alternating nodes every 135 synodic months (≈ 3986.63 days, or 11 years minus 1 month). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee), but groupings of 3 tritos cycles (≈ 33 years minus 3 months) come close (≈ 434.044 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2060 :
| 1809 Oct 23 (Saros 133) | 1809 Oct 23 (Saros 133) | 1820 Sep 22 (Saros 134) | 1820 Sep 22 (Saros 134) | 1831 Aug 23 (Saros 135) | 1831 Aug 23 (Saros 135) | 1842 Jul 22 (Saros 136) | 1842 Jul 22 (Saros 136) | 1853 Jun 21 (Saros 137) | 1853 Jun 21 (Saros 137) |
| 1864 May 21 (Saros 138) | 1864 May 21 (Saros 138) | 1875 Apr 20 (Saros 139) | 1875 Apr 20 (Saros 139) | 1886 Mar 20 (Saros 140) | 1886 Mar 20 (Saros 140) | 1897 Feb 17 (Saros 141) | 1897 Feb 17 (Saros 141) | 1908 Jan 18 (Saros 142) | 1908 Jan 18 (Saros 142) |
| 1918 Dec 17 (Saros 143) | 1918 Dec 17 (Saros 143) | 1929 Nov 17 (Saros 144) | 1929 Nov 17 (Saros 144) | 1940 Oct 16 (Saros 145) | 1940 Oct 16 (Saros 145) | 1951 Sep 15 (Saros 146) | 1951 Sep 15 (Saros 146) | 1962 Aug 15 (Saros 147) | 1962 Aug 15 (Saros 147) |
| 1973 Jul 15 (Saros 148) | 1973 Jul 15 (Saros 148) | 1984 Jun 13 (Saros 149) | 1984 Jun 13 (Saros 149) | | | | | | |
| | | | | | | 2060 Nov 08 (Saros 156) | 2060 Nov 08 (Saros 156) |

### Inex series

This eclipse is a part of the long period inex cycle, repeating at alternating nodes, every 358 synodic months (≈ 10,571.95 days, or 29 years minus 20 days). Their appearance and longitude are irregular due to a lack of synchronization with the anomalistic month (period of perigee). However, groupings of 3 inex cycles (≈ 87 years minus 2 months) comes close (≈ 1,151.02 anomalistic months), so eclipses are similar in these groupings.
Series members between 1801 and 2154 :
| 1806 Dec 25 (Saros 141) | 1806 Dec 25 (Saros 141) | 1835 Dec 05 (Saros 142) | 1835 Dec 05 (Saros 142) | 1864 Nov 13 (Saros 143) | 1864 Nov 13 (Saros 143) |
| 1893 Oct 25 (Saros 144) | 1893 Oct 25 (Saros 144) | 1922 Oct 06 (Saros 145) | 1922 Oct 06 (Saros 145) | 1951 Sep 15 (Saros 146) | 1951 Sep 15 (Saros 146) |
| 1980 Aug 26 (Saros 147) | 1980 Aug 26 (Saros 147) | 2009 Aug 06 (Saros 148) | 2009 Aug 06 (Saros 148) | 2038 Jul 16 (Saros 149) | 2038 Jul 16 (Saros 149) |
| 2067 Jun 27 (Saros 150) | 2067 Jun 27 (Saros 150) | 2096 Jun 06 (Saros 151) | 2096 Jun 06 (Saros 151) | 2125 May 17 (Saros 152) | 2125 May 17 (Saros 152) |
| 2154 Apr 28 (Saros 153) ||

### Half-Saros cycle

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros). This lunar eclipse is related to two total solar eclipses of Solar Saros 153.
| September 10, 1942 | September 20, 1960 |