An annular solar eclipse occurred at the Moon’s ascending node of orbit on Saturday, August 22, 1998,[1][2] [3] [4] with a magnitude of 0.9734. A solar eclipse occurs when the Moon passes between Earth and the Sun, thereby totally or partly obscuring the image of the Sun for a viewer on Earth. An annular solar eclipse occurs when the Moon's apparent diameter is smaller than the Sun's, blocking most of the Sun's light and causing the Sun to look like an annulus (ring). An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring about 5.2 days before apogee (on August 27, 1998, at 7:30 UTC), the Moon's apparent diameter was smaller.[5]
| Solar eclipse of August 22, 1998 | |
|---|---|
 Map | |
| Type of eclipse | |
| Nature | Annular |
| Gamma | −0.2644 |
| Magnitude | 0.9734 |
| Maximum eclipse | |
| Duration | 194 s (3 min 14 s) |
| Coordinates | 3°00′S 145°24′E / 3°S 145.4°E |
| Max. width of band | 99 km (62 mi) |
| Times (UTC) | |
| Greatest eclipse | 2:07:11 |
| References | |
| Saros | 135 (38 of 71) |
| Catalog # (SE5000) | 9504 |
Annularity was visible in Indonesia, Malaysia, Papua New Guinea, Solomon Islands (Bellona Island and Rennell Island) and Vanuatu. A partial eclipse was visible for parts of Southeast Asia, East Asia, Australia, and Oceania.
Images
edit
Observations
editIt is usually very dry in Malaysia in August. But due to the El Niño, it rained every day for 2 weeks before the eclipse. On the eclipse day, the sun kept going in and out the gaps of the clouds at first, and later the clouds dispersed near Kota Tinggi District, the observation site of NASA's Johnson Space Center. The whole annular phase was seen. The sky cleared up completely 40 minutes later.[6]
Eclipse details
editShown below are two tables displaying details about this particular solar eclipse. The first table outlines times at which the moon's penumbra or umbra attains the specific parameter, and the second table describes various other parameters pertaining to this eclipse.[7]
| Event | Time (UTC) |
|---|---|
| First Penumbral External Contact | 1998 August 21 at 23:11:19.7 UTC |
| First Umbral External Contact | 1998 August 22 at 00:15:19.1 UTC |
| First Central Line | 1998 August 22 at 00:16:42.3 UTC |
| First Umbral Internal Contact | 1998 August 22 at 00:18:05.7 UTC |
| First Penumbral Internal Contact | 1998 August 22 at 01:26:40.7 UTC |
| Greatest Duration | 1998 August 22 at 01:59:47.4 UTC |
| Ecliptic Conjunction | 1998 August 22 at 02:04:08.9 UTC |
| Greatest Eclipse | 1998 August 22 at 02:07:10.5 UTC |
| Equatorial Conjunction | 1998 August 22 at 02:15:05.3 UTC |
| Last Penumbral Internal Contact | 1998 August 22 at 02:47:26.3 UTC |
| Last Umbral Internal Contact | 1998 August 22 at 03:56:07.6 UTC |
| Last Central Line | 1998 August 22 at 03:57:33.7 UTC |
| Last Umbral External Contact | 1998 August 22 at 03:58:59.8 UTC |
| Last Penumbral External Contact | 1998 August 22 at 05:03:03.8 UTC |
| Parameter | Value |
|---|---|
| Eclipse Magnitude | 0.97336 |
| Eclipse Obscuration | 0.94742 |
| Gamma | −0.26441 |
| Sun Right Ascension | 10h03m45.9s |
| Sun Declination | +11°53'26.2" |
| Sun Semi-Diameter | 15'48.7" |
| Sun Equatorial Horizontal Parallax | 08.7" |
| Moon Right Ascension | 10h03m30.7s |
| Moon Declination | +11°39'14.3" |
| Moon Semi-Diameter | 15'09.7" |
| Moon Equatorial Horizontal Parallax | 0°55'38.7" |
| ΔT | 63.3 s |
Eclipse season
editThis 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.
| August 8 Descending node (full moon) |
August 22 Ascending node (new moon) |
September 6 Descending node (full moon) |
|---|---|---|
 |
|
|
| Penumbral lunar eclipse Lunar Saros 109 |
Annular solar eclipse Solar Saros 135 |
Penumbral lunar eclipse Lunar Saros 147 |
Related eclipses
editEclipses in 1998
edit- A total solar eclipse on February 26.
- A penumbral lunar eclipse on March 13.
- A penumbral lunar eclipse on August 8.
- An annular solar eclipse on August 22.
- A penumbral lunar eclipse on September 6.
Metonic
edit- Preceded by: Solar eclipse of November 3, 1994
- Followed by: Solar eclipse of June 10, 2002
Tzolkinex
edit- Preceded by: Solar eclipse of July 11, 1991
- Followed by: Solar eclipse of October 3, 2005
Half-Saros
edit- Preceded by: Lunar eclipse of August 16, 1989
- Followed by: Lunar eclipse of August 28, 2007
Tritos
edit- Preceded by: Solar eclipse of September 23, 1987
- Followed by: Solar eclipse of July 22, 2009
Solar Saros 135
edit- Preceded by: Solar eclipse of August 10, 1980
- Followed by: Solar eclipse of September 1, 2016
Inex
edit- Preceded by: Solar eclipse of September 11, 1969
- Followed by: Solar eclipse of August 2, 2027
Triad
edit- Preceded by: Solar eclipse of October 22, 1911
- Followed by: Solar eclipse of June 22, 2085
Solar eclipses of 1997–2000
editThis eclipse is a member of a semester series. An eclipse in a semester series of solar eclipses repeats approximately every 177 days and 4 hours (a semester) at alternating nodes of the Moon's orbit.[8]
The partial solar eclipses on July 1, 2000 and December 25, 2000 occur in the next lunar year eclipse set.
| Solar eclipse series sets from 1997 to 2000 | ||||||
|---|---|---|---|---|---|---|
| Descending node | Ascending node | |||||
| Saros | Map | Gamma | Saros | Map | Gamma | |
120 Totality in Chita, Russia |
March 9, 1997 Total |
0.9183 | 125 | September 2, 1997 Partial |
−1.0352 | |
130 Totality near Guadeloupe |
February 26, 1998 Total |
0.2391 | 135 | August 22, 1998 Annular |
−0.2644 | |
| 140 | February 16, 1999 Annular |
−0.4726 | 145 Totality in France |
August 11, 1999 Total |
0.5062 | |
| 150 | February 5, 2000 Partial |
−1.2233 | 155 | July 31, 2000 Partial |
1.2166 | |
Saros 135
editThis eclipse is a part of Saros series 135, repeating every 18 years, 11 days, and containing 71 events. The series started with a partial solar eclipse on July 5, 1331. It contains annular eclipses from October 21, 1511 through February 24, 2305; hybrid eclipses on March 8, 2323 and March 18, 2341; and total eclipses from March 29, 2359 through May 22, 2449. The series ends at member 71 as a partial eclipse on August 17, 2593. Its 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.
The longest duration of annularity was produced by member 16 at 10 minutes, 41 seconds on December 24, 1601, and the longest duration of totality will be produced by member 62 at 2 minutes, 27 seconds on May 12, 2431. All eclipses in this series occur at the Moon’s ascending node of orbit.[9]
| Series members 28–49 occur between 1801 and 2200: | ||
|---|---|---|
| 28 | 29 | 30 |
 May 5, 1818 |
 May 15, 1836 |
 May 26, 1854 |
| 31 | 32 | 33 |
 June 6, 1872 |
 June 17, 1890 |
 June 28, 1908 |
| 34 | 35 | 36 |
 July 9, 1926 |
 July 20, 1944 |
 July 31, 1962 |
| 37 | 38 | 39 |
 August 10, 1980 |
August 22, 1998 |
 September 1, 2016 |
| 40 | 42 | 42 |
 September 12, 2034 |
 September 22, 2052 |
 October 4, 2070 |
| 43 | 44 | 45 |
 October 14, 2088 |
 October 26, 2106 |
 November 6, 2124 |
| 46 | 47 | 48 |
 November 17, 2142 |
 November 27, 2160 |
 December 9, 2178 |
| 49 | ||
 December 19, 2196 | ||
Metonic series
editThe metonic series repeats eclipses every 19 years (6939.69 days), lasting about 5 cycles. Eclipses occur in nearly the same calendar date. In addition, the octon subseries repeats 1/5 of that or every 3.8 years (1387.94 days). All eclipses in this table occur at the Moon's ascending node.
| 20 eclipse events between June 10, 1964 and August 21, 2036 | ||||
|---|---|---|---|---|
| June 10–11 | March 28–29 | January 14–16 | November 3 | August 21–22 |
| 117 | 119 | 121 | 123 | 125 |
 June 10, 1964 |
 March 28, 1968 |
 January 16, 1972 |
 November 3, 1975 |
 August 22, 1979 |
| 127 | 129 | 131 | 133 | 135 |
 June 11, 1983 |
 March 29, 1987 |
 January 15, 1991 |
 November 3, 1994 |
August 22, 1998 |
| 137 | 139 | 141 | 143 | 145 |
 June 10, 2002 |
 March 29, 2006 |
 January 15, 2010 |
 November 3, 2013 |
 August 21, 2017 |
| 147 | 149 | 151 | 153 | 155 |
 June 10, 2021 |
 March 29, 2025 |
 January 14, 2029 |
 November 3, 2032 |
 August 21, 2036 |
Tritos series
editThis 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 2200 | ||||
|---|---|---|---|---|
 March 4, 1802 (Saros 117) |
 February 1, 1813 (Saros 118) |
 January 1, 1824 (Saros 119) |
 November 30, 1834 (Saros 120) |
 October 30, 1845 (Saros 121) |
 September 29, 1856 (Saros 122) |
 August 29, 1867 (Saros 123) |
 July 29, 1878 (Saros 124) |
 June 28, 1889 (Saros 125) |
 May 28, 1900 (Saros 126) |
 April 28, 1911 (Saros 127) |
 March 28, 1922 (Saros 128) |
 February 24, 1933 (Saros 129) |
 January 25, 1944 (Saros 130) |
 December 25, 1954 (Saros 131) |
 November 23, 1965 (Saros 132) |
 October 23, 1976 (Saros 133) |
 September 23, 1987 (Saros 134) |
August 22, 1998 (Saros 135) |
 July 22, 2009 (Saros 136) |
 June 21, 2020 (Saros 137) |
 May 21, 2031 (Saros 138) |
 April 20, 2042 (Saros 139) |
 March 20, 2053 (Saros 140) |
 February 17, 2064 (Saros 141) |
 January 16, 2075 (Saros 142) |
 December 16, 2085 (Saros 143) |
 November 15, 2096 (Saros 144) |
 October 16, 2107 (Saros 145) |
 September 15, 2118 (Saros 146) |
 August 15, 2129 (Saros 147) |
 July 14, 2140 (Saros 148) |
 June 14, 2151 (Saros 149) |
 May 14, 2162 (Saros 150) |
 April 12, 2173 (Saros 151) |
 March 12, 2184 (Saros 152) |
 February 10, 2195 (Saros 153) | |||
Inex series
editThis 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 2200 | ||
|---|---|---|
 December 20, 1824 (Saros 129) |
 November 30, 1853 (Saros 130) |
 November 10, 1882 (Saros 131) |
 October 22, 1911 (Saros 132) |
 October 1, 1940 (Saros 133) |
 September 11, 1969 (Saros 134) |
| August 22, 1998 (Saros 135) |
 August 2, 2027 (Saros 136) |
 July 12, 2056 (Saros 137) |
 June 22, 2085 (Saros 138) |
 June 3, 2114 (Saros 139) |
 May 14, 2143 (Saros 140) |
 April 23, 2172 (Saros 141) |
||
Notes
edit- ^ "August 21–22, 1998 Annular Solar Eclipse". timeanddate. Retrieved 10 August 2024.
- ^ "Clouds may put eclipse in shade". The Sydney Morning Herald. Sydney, New South Wales, New South Wales, Australia. 1998-08-22. p. 5. Retrieved 2023-10-21 – via Newspapers.com.
- ^ "Saturday". Newsday (Suffolk Edition). 1998-08-19. p. 114. Retrieved 2023-10-21 – via Newspapers.com.
- ^ "Eclipse Aug. 23". Mitchell Tribune. 1998-08-05. p. 12. Retrieved 2023-10-21 – via Newspapers.com.
- ^ "Moon Distances for London, United Kingdom, England". timeanddate. Retrieved 10 August 2024.
- ^ Paul Maley. "The August 22, 1998 Annular Solar Eclipse Seen from Malaysia". Archived from the original on 30 October 2020.
- ^ "Annular Solar Eclipse of 1998 Aug 22". EclipseWise.com. Retrieved 10 August 2024.
- ^ van Gent, R.H. "Solar- and Lunar-Eclipse Predictions from Antiquity to the Present". A Catalogue of Eclipse Cycles. Utrecht University. Retrieved 6 October 2018.
- ^ "NASA - Catalog of Solar Eclipses of Saros 135". eclipse.gsfc.nasa.gov.
References
edit- Earth visibility chart and eclipse statistics Eclipse Predictions by Fred Espenak, NASA/GSFC
Photos:
- An Annular Eclipse of the Sun APOD 8/24/1998, from Mersing on the East Coast of Malaysia