Solar eclipse of September 23, 1987

Solar eclipse of September 23, 1987
Solar eclipse of September 23, 1987
	Map
Type of eclipse
Nature	Annular
Gamma	0.2787
Magnitude	0.9634
Maximum eclipse
Duration	229 s (3 min 49 s)
Coordinates	14°18′N 138°24′E / 14.3°N 138.4°E
Max. width of band	137 km (85 mi)
Times (UTC)
Greatest eclipse	3:12:22
References
Saros	134 (42 of 71)
Catalog # (SE5000)	9481

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.

Observation[edit]

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]

Related eclipses[edit]

Eclipses of 1987[edit]

A hybrid solar eclipse on March 29.
A penumbral lunar eclipse on April 14.
An annular solar eclipse on September 23.
A penumbral lunar eclipse on October 7.

Solar eclipses of 1986–1989[edit]

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

Solar eclipse series sets from 1986 to 1989
Ascending node			Descending node
Saros	Map	Gamma	Saros	Map	Gamma
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[edit]

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[edit]

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[edit]

^ 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.
^ 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.
^ 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.
^ "NASA - Catalog of Solar Eclipses of Saros 134". eclipse.gsfc.nasa.gov.