Solar eclipse of September 23, 1987

An annular solar eclipse occurred on September 23, 1987. 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. Annularity was visible in the Soviet Union (today's Kazakhstan), China (including Shanghai), southwestern Mongolia, Okinawa Islands of Japan except Kume Island and the southwestern tip of Kerama Islands, the Federal States of Micronesia, Papua New Guinea, Solomon Islands, Rotuma Islands of Fiji, Wallis Islands and West Samoa (the name changed to Samoa later). Occurring only 5 days after apogee (Apogee on September 18, 1987), the Moon's apparent diameter was relatively small.

Solar eclipse of September 23, 1987
Map
Type of eclipse
NatureAnnular
Gamma0.2787
Magnitude0.9634
Maximum eclipse
Duration229 sec (3 m 49 s)
Coordinates14.3°N 138.4°E / 14.3; 138.4
Max. width of band137 km (85 mi)
Times (UTC)
Greatest eclipse3:12:22
References
Saros134 (42 of 71)
Catalog # (SE5000)9481

Observation

Five radio observation stations were present in China at the time of the eclipse, two of which were within the annularity, in Ürümqi and Shanghai respectively. A partial solar eclipse was observed from the other three, including one in Nanjing where the eclipse was close to annularity, and the rest two in Beijing and Kunming. The Department of Mathematics and Physics of the Chinese Academy of Sciences and the Chinese Astronomical Society held a meeting in Kunming in December 1986, deciding that on-site observation would be conducted at each station, among which the Shanghai Astronomical Observatory was considered to have the best location with a larger magnitude of the eclipse, longer duration and larger solar zenith angle. The Shanghai Astronomical Observatory conducted observations with seven different wave bands using a 25-metre radio telescope.[1] The Yunnan Astronomical Observatory located in Kunming also conducted a multi-band joint observation of the partial solar eclipse.[2]

The Chinese Research Institute of Radio Wave Propagation conducted observations with a high-frequency skywave radar located in Xinxiang on the southern limit of annularity. Uneven structure and motion were observed in the ionosphere, the highest operating frequency was found changed during the eclipse, and large-scale fluctuations continued after the eclipse.[3]

Eclipses of 1987

Solar eclipses of 1986–1989

There were 8 solar eclipses between April 9, 1986 and August 31, 1989.

Solar eclipse series sets from 1986–1989
Ascending node   Descending node
SarosMapGamma SarosMapGamma
119
1986 April 9
Partial		−1.08215 124
1986 October 3
Hybrid		0.99305
129
1987 March 29
Hybrid		−0.30531 134
1987 September 23
Annular		0.27869
139
1988 March 18
Total		0.41879 144
1988 September 11
Annular		−0.46811
149
1989 March 7
Partial		1.09815 154
1989 August 31
Partial		−1.19279

Saros 134

It is a part of Saros cycle 134, repeating every 18 years, 11 days, containing 71 events. The series started with a partial solar eclipse on June 22, 1248. It contains total eclipses from October 9, 1428 through December 24, 1554 and hybrid eclipses from January 3, 1573 through June 27, 1843, and annular eclipses from July 8, 1861 through May 21, 2384. The series ends at member 71 as a partial eclipse on August 6, 2510. The longest duration of totality was 1 minutes, 30 seconds on October 9, 1428. All eclipses in this series occur at the Moon’s descending node.[4]

Series members 32–48 occur between 1801 and 2100:
32 33 34

June 6, 1807
June 16, 1825
June 27, 1843
35 36 37

July 8, 1861
July 19, 1879
July 29, 1897
38 39 40

August 10, 1915
August 21, 1933
September 1, 1951
41 42 43

September 11, 1969
September 23, 1987
October 3, 2005
44 45 46

October 14, 2023
October 25, 2041
November 5, 2059
47 48

November 15, 2077
November 27, 2095

Metonic series

The 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 descending node.

21 eclipse events, progressing from north to south between July 11, 1953 and July 11, 2029
July 10–12 April 29–30 February 15–16 December 4–5 September 21–23
116 118 120 122 124

July 11, 1953
April 30, 1957
February 15, 1961
December 4, 1964
September 22, 1968
126 128 130 132 134

July 10, 1972
April 29, 1976
February 16, 1980
December 4, 1983
September 23, 1987
136 138 140 142 144

July 11, 1991
April 29, 1995
February 16, 1999
December 4, 2002
September 22, 2006
146 148 150 152 154

July 11, 2010
April 29, 2014
February 15, 2018
December 4, 2021
September 21, 2025
156 158 160 162 164

July 11, 2029

Notes
  1. 纪树臣 季德盛 梁世光 (1988). "1987年9月23日沪台25米天线观测选题及方案". 云南天文台台刊 (4): 100–105.
  2. 纪树臣 杨荣邦 谢瑞祥 (1989). "1987年9月23日日偏食云台多波段联合观测". 云南天文台台刊 (3): 46–53.
  3. 焦培南 (1990). "1987年9月23日日环食的电离层波动现象". 地球物理学报. 33 (4): 391–398. Archived from the original on 21 July 2015.
  4. "NASA - Catalog of Solar Eclipses of Saros 134". eclipse.gsfc.nasa.gov.

References
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