Key to Catalog of Lunar Eclipses
Fred Espenak
Each line in the Catalog of Lunar Eclipses corresponds to a single lunar eclipse and provides concise parameters to characterize the eclipse. The calendar date and Terrestrial Dynamical Time (TD) of the instant of Greatest Eclipse are given along with the adopted value of ΔT. The Lunation Number and the Saros series are listed along with the eclipse type (N=Penumbral, P=Partial, or T=Total). The quincena solar eclipse parameter identifies the type of solar eclipse that precedes and/or succeeds a lunar eclipse. Gamma is the distance from the Moon's center to the axis of Earth's shadow cones at greatest eclipse, while the penumbral eclipse magnitude and umbral eclipse magnitude are defined as the fractions of the Moon's diameter immersed in the penumbral and umbral shadows at that instant. The duration of the penumbral, partial, and total eclipse phases are given in minutes. Finally, the geographic latitude and longitude are given for the location where the Moon lies in the zenith at greatest eclipse. A more detailed description of each field appears in the Key to Catalog of Lunar Eclipses below.
| Key to Catalog of Lunar Eclipses | |
| Parameter | Description |
| Calendar Date | the calendar date of the eclipse at the instant of Greatest Eclipse; the Gregorian Calendar is used for dates after 1582 Oct 15, while the older Julian Calendar is used for prior dates; |
| TD of Greatest Eclipse | the Terrestrial Dynamical Time (TD) of the eclipse at the instant of Greatest Eclipse; |
| ΔT | a measure of the accumulated clock error due to variations in the rotation period of Earth; ΔT is difference between Terrestrial Dynamical Time (TD) and Universal Time (UT1) (i.e., ΔT = TD - UT1 ); |
| ΔT Sigma | a measure of the standard error in ΔT; values of ΔT in the distant past and in the future are extrapolations with an uncertainty reflected in the value of ΔT Sigma; |
| Luna Num | the Lunation Number of the synodic month in which the lunar eclipse takes place; |
| Saros | the number of the Saros series to which the eclipse belongs; |
| Ecl Type | the Eclipse Type is a 2-character code that describes the classification of an eclipse; The first character describes the kind or category of the eclipse where:
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| QSE | the Quincena Solar Eclipse parameter identifies the type of solar eclipse that precedes and/or succeeds a lunar eclipse where:
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| Gamma | the distance (in units of equatorial Earth radii) of the center of the Moon’s disk from the center of Earth’s shadow at the instant of Greatest Eclipse; since this is the instant when the Moon passes closest to the axis of Earth’s umbral shadow, Gamma is, by definition, the minimum distance of the shadow axis from center of the Moon; |
| Pen Mag | the Penumbral Eclipse Magnitude is the fraction of the Moon’s diameter occulted by Earth’s penumbral shadow at the instant of Greatest Eclipse; the Penumbral Eclipse Magnitude is less that 1.0 for partial penumbral eclipses (and equal to or greater than 1.0 for total penumbral eclipses); the Penumbral Eclipse Magnitude is equal to or greater than 1.0 for most partial eclipses and for all total eclipses; |
| Um Mag | the Umbral Eclipse Magnitude is the fraction of the Moon’s diameter occulted by Earth’s umbral shadow at the instant of Greatest Eclipse; the Umbral Eclipse Magnitude is less that 1.0 for partial eclipses (and less than 0.0 for penumbral eclipses); the Umbral Eclipse Magnitude is equal to or greater than 1.0 for total eclipses; |
| Pen Dur | the Penumbral Duration is the elapsed time (hours, minutes, seconds) between the penumbral contacts P1 and P4; this is the duration of the penumbral phase for penumbral eclipses; for partial and total eclipses, this period encompasses the entire eclipse (including all penumbral, partial and total phases); see Contact Times for more information; |
| Par Dur | the Partial Duration is the elapsed time (hours, minutes, seconds) between umbral contacts U1 and U4; this is the duration of the partial phase for partial eclipses; for total eclipses, this period encompasses the entire umbral eclipse (including all partial and total phases); see Contact Times for more information; |
| Tot Dur | the Total Duration is the elapsed time (hours, minutes, seconds) between umbral contacts U2 and U3; this is the duration of the total phase for total eclipses; see Contact Times for more information; |
| Zen Lat | the Zenith Latitude is the geographic latitude where the Moon appears in the zenith at the instant of Greatest Eclipse; |
| Zen Long | the Zenith Longitude is the geographic longitude where the Moon appears in the zenith at the instant of Greatest Eclipse; |
Additional Lunar Eclipse Links
- Home - home page of EclipseWise with predictions for both solar and lunar eclipses
- Lunar Eclipses - primary page for lunar eclipse predictions
- Lunar Eclipse Links - detailed directory of links
- Six Millennium Catalog of Lunar Eclipses - covers the years -2999 to +3000 (3000 BCE to 3000 CE)
- Javascript Lunar Eclipse Explorer - calculate all lunar eclipses visible from a city
- Thousand Year Canon of Lunar Eclipses 1501 to 2500 - link to the publication
Acknowledgments
Some of the data presented in the Catalog of Lunar Eclipses were previously published in the Five Millennium Canon of Lunar Eclipses: -1999 to +3000 and the 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 this data when accompanied by an acknowledgment:
"Eclipse Predictions by Fred Espenak, www.EclipseWise.com"
Lunar Eclipse Publications
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