September 1977 lunar eclipse
Penumbral eclipse | |||||||||
Date | September 27, 1977 | ||||||||
---|---|---|---|---|---|---|---|---|---|
Gamma | 1.0768 | ||||||||
Magnitude | −0.1361 | ||||||||
Saros cycle | 117 (50 of 72) | ||||||||
Penumbral | 257 minutes, 30 seconds | ||||||||
| |||||||||
A penumbral lunar eclipse occurred at the Moon’s descending node of orbit on Tuesday, September 27, 1977,[1] with an umbral magnitude of −0.1361. 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 6.25 days before apogee (on October 3, 1977, at 14:45 UTC), the Moon's apparent diameter was smaller.[2]
Visibility
[edit]The eclipse was completely visible over North America, northwestern South America, and the central and eastern Pacific Ocean, seen rising over east and northeast Asia and Australia and setting over much of South America and the Atlantic Ocean.[3]
Eclipse details
[edit]Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.[4]
Parameter | Value |
---|---|
Penumbral Magnitude | 0.90076 |
Umbral Magnitude | −0.13605 |
Gamma | 1.07682 |
Sun Right Ascension | 12h15m08.1s |
Sun Declination | -01°38'19.9" |
Sun Semi-Diameter | 15'57.6" |
Sun Equatorial Horizontal Parallax | 08.8" |
Moon Right Ascension | 00h13m53.7s |
Moon Declination | +02°36'15.1" |
Moon Semi-Diameter | 15'23.6" |
Moon Equatorial Horizontal Parallax | 0°56'29.6" |
ΔT | 48.3 s |
Eclipse season
[edit]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.
September 27 Descending node (full moon) |
October 12 Ascending node (new moon) |
---|---|
Penumbral lunar eclipse Lunar Saros 117 |
Total solar eclipse Solar Saros 143 |
Related eclipses
[edit]Eclipses in 1977
[edit]- A partial lunar eclipse on April 4.
- An annular solar eclipse on April 18.
- A penumbral lunar eclipse on September 27.
- A total solar eclipse on October 12.
Metonic
[edit]- Preceded by: Lunar eclipse of December 10, 1973
- Followed by: Lunar eclipse of July 17, 1981
Tzolkinex
[edit]- Preceded by: Lunar eclipse of August 17, 1970
- Followed by: Lunar eclipse of November 8, 1984
Half-Saros
[edit]- Preceded by: Solar eclipse of September 22, 1968
- Followed by: Solar eclipse of October 3, 1986
Tritos
[edit]- Preceded by: Lunar eclipse of October 29, 1966
- Followed by: Lunar eclipse of August 27, 1988
Lunar Saros 117
[edit]- Preceded by: Lunar eclipse of September 17, 1959
- Followed by: Lunar eclipse of October 8, 1995
Inex
[edit]- Preceded by: Lunar eclipse of October 18, 1948
- Followed by: Lunar eclipse of September 7, 2006
Triad
[edit]- Preceded by: Lunar eclipse of November 26, 1890
- Followed by: Lunar eclipse of July 28, 2064
Lunar eclipses of 1977–1980
[edit]Lunar eclipse series sets from 1977–1980 | ||||||||
---|---|---|---|---|---|---|---|---|
Ascending node | Descending node | |||||||
Saros | Date viewing |
Type chart |
Gamma | Saros | Date viewing |
Type chart |
Gamma | |
112 | 1977 Apr 04 |
Partial |
−0.91483 | 117 | 1977 Sep 27 |
Penumbral |
1.07682 | |
122 | 1978 Mar 24 |
Total |
−0.21402 | 127 | 1978 Sep 16 |
Total |
0.29510 | |
132 | 1979 Mar 13 |
Partial |
0.52537 | 137 | 1979 Sep 06 |
Total |
−0.43050 | |
142 | 1980 Mar 01 |
Penumbral |
1.22701 | 147 | 1980 Aug 26 |
Penumbral |
−1.16082 | |
Last set | 1976 May 13 | Last set | 1976 Nov 06 | |||||
Next set | 1981 Jan 20 | Next set | 1980 Jul 27 |
Half-Saros cycle
[edit]A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).[5] This lunar eclipse is related to two solar eclipses of Solar Saros 124.
September 22, 1968 | October 3, 1986 |
---|---|
See also
[edit]Notes
[edit]- ^ "September 26–27, 1977 Penumbral Lunar Eclipse". timeanddate. Retrieved 4 January 2025.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 4 January 2025.
- ^ "Penumbral Lunar Eclipse of 1977 Sep 27" (PDF). NASA. Retrieved 4 January 2025.
- ^ "Penumbral Lunar Eclipse of 1977 Sep 27". EclipseWise.com. Retrieved 4 January 2025.
- ^ Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros
External links
[edit]- 1977 Sep 27 chart Eclipse Predictions by Fred Espenak, NASA/GSFC