January 1999 lunar eclipse

{{Infobox lunar eclipse

| type = penumbral

| image = Lunar eclipse chart close-1999Jan31.png

| caption = The Moon's hourly motion shown right to left

| date = January 31, 1999

| gamma = −1.0190

| magnitude = −0.0258

| saros_ser = 114

| saros_no = 58 of 71

| penumbral = 261 minutes, 41 seconds

| p1 = 14:06:38

| greatest = 16:17:31

| p4 = 18:28:20

| previous = September 1998

| next = July 1999

}}

A penumbral lunar eclipse occurred at the Moon’s ascending node of orbit on Sunday, January 31, 1999,{{cite web|title=January 31–February 1, 1999 Penumbral Lunar Eclipse|url=https://www.timeanddate.com/eclipse/lunar/1999-january-31|publisher=timeanddate|access-date=9 January 2025}} with an umbral magnitude of −0.0258. It was a relatively rare total penumbral lunar eclipse, with the Moon passing entirely within the penumbral shadow without entering the darker umbral shadow.[http://adsabs.harvard.edu/full/1980JRASC..74..291M Total Penumbral Lunar Eclipses, Jean Meeus, June 1980] 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 4.8 days after perigee (on January 26, 1999, at 21:25 UTC), the Moon's apparent diameter was larger.{{cite web|title=Moon Distances for London, United Kingdom, England|url=https://www.timeanddate.com/astronomy/moon/distance.html?year=1999&n=136|publisher=timeanddate|access-date=9 January 2025}}

Visibility

The eclipse was completely visible over Asia and Australia, seen rising over much of Africa, Europe, and the Middle East and setting over western North America and the central Pacific Ocean.{{cite web|title=Penumbral Lunar Eclipse of 1999 Jan 31|url=https://eclipse.gsfc.nasa.gov/LEplot/LEplot1951/LE1999Jan31N.pdf|publisher=NASA|access-date=9 January 2025}}

class=wikitable

|300px 300px

Gallery

480px
This simulated view compares this penumbral eclipse (left) to the full moon (right) as it appeared an hour before the eclipse.

Eclipse details

Shown below is a table displaying details about this particular solar eclipse. It describes various parameters pertaining to this eclipse.{{cite web|title=Penumbral Lunar Eclipse of 1999 Jan 31|url=https://eclipsewise.com/lunar/LEprime/1901-2000/LE1999Jan31Nprime.html|publisher=EclipseWise.com|access-date=9 January 2025}}

class="wikitable" align="{{{align|left}}}" style="margin:{{#ifeq:{{{align}}}|right|0 0 0.5em 1em|0 1em 0.5em 0}}"

|+January 31, 1999 Lunar Eclipse Parameters

! Parameter

! Value

Penumbral Magnitude

| 1.00272

Umbral Magnitude

| −0.02583

Gamma

| −1.01898

Sun Right Ascension

| 20h55m10.7s

Sun Declination

| -17°22'34.0"

Sun Semi-Diameter

| 16'14.0"

Sun Equatorial Horizontal Parallax

| 08.9"

Moon Right Ascension

| 08h54m26.3s

Moon Declination

| +16°24'30.3"

Moon Semi-Diameter

| 15'47.0"

Moon Equatorial Horizontal Parallax

| 0°57'55.6"

ΔT

| 63.5 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.

class="wikitable"

|+ Eclipse season of January–February 1999

! January 31
Ascending node (full moon)
!! February 16
Descending node (new moon)

200px

align=center

| Penumbral lunar eclipse
Lunar Saros 114

Annular solar eclipse
Solar Saros 140

Related eclipses

= Eclipses in 1999 =

A penumbral lunar eclipse on January 31.
An annular solar eclipse on February 16.
A partial lunar eclipse on July 28.
A total solar eclipse on August 11.

= Metonic =

Preceded by: Lunar eclipse of April 15, 1995
Followed by: Lunar eclipse of November 20, 2002

= Tzolkinex =

Preceded by: Lunar eclipse of December 21, 1991
Followed by: Lunar eclipse of March 14, 2006

= Half-Saros =

Preceded by: Solar eclipse of January 26, 1990
Followed by: Solar eclipse of February 7, 2008

= Tritos =

Preceded by: Lunar eclipse of March 3, 1988
Followed by: Lunar eclipse of December 31, 2009

= Lunar Saros 114 =

Preceded by: Lunar eclipse of January 20, 1981
Followed by: Lunar eclipse of February 11, 2017

= Inex =

Preceded by: Lunar eclipse of February 21, 1970
Followed by: Lunar eclipse of January 12, 2028

= Triad =

Preceded by: Lunar eclipse of April 1, 1912
Followed by: Lunar eclipse of December 1, 2085

= Lunar eclipses of 1998–2002 =

= Saros 114 =

= Tritos series =

= Inex series =

= Half-Saros cycle =

A lunar eclipse will be preceded and followed by solar eclipses by 9 years and 5.5 days (a half saros).Mathematical Astronomy Morsels, Jean Meeus, p.110, Chapter 18, The half-saros This lunar eclipse is related to two annular solar eclipses of Solar Saros 121.

class=wikitable