Solar eclipse of September 23, 1987


An annular solar eclipse occurred at the Moon's descending node of orbit on Wednesday, September 23, 1987, with a magnitude of 0.9634. 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. An annular eclipse appears as a partial eclipse over a region of the Earth thousands of kilometres wide. Occurring only 5 days after apogee, the Moon's apparent diameter was smaller.
Annularity was visible in the Soviet Union, China, 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. A partial eclipse was visible for parts of South Asia, Southeast Asia, East Asia, Australia, Oceania, and Hawaii.

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. The Yunnan Astronomical Observatory located in Kunming also conducted a multi-band joint observation of the partial solar eclipse.
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.

Eclipse details

Shown 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.
EventTime
First Penumbral External Contact1987 September 23 at 00:15:50.5 UTC
First Umbral External Contact1987 September 23 at 01:20:19.5 UTC
First Central Line1987 September 23 at 01:22:07.2 UTC
First Umbral Internal Contact1987 September 23 at 01:23:55.0 UTC
First Penumbral Internal Contact1987 September 23 at 02:33:48.6 UTC
Greatest Duration1987 September 23 at 02:45:44.7 UTC
Equatorial Conjunction1987 September 23 at 02:54:28.0 UTC
Ecliptic Conjunction1987 September 23 at 03:09:08.4 UTC
Greatest Eclipse1987 September 23 at 03:12:21.6 UTC
Last Penumbral Internal Contact1987 September 23 at 03:51:20.8 UTC
Last Umbral Internal Contact1987 September 23 at 05:01:01.1 UTC
Last Central Line1987 September 23 at 05:02:46.3 UTC
Last Umbral External Contact1987 September 23 at 05:04:31.2 UTC
Last Penumbral External Contact1987 September 23 at 06:08:54.0 UTC

ParameterValue
Eclipse Magnitude0.96337
Eclipse Obscuration0.92807
Gamma0.27869
Sun Right Ascension11h58m25.1s
Sun Declination+00°10'17.1"
Sun Semi-Diameter15'56.2"
Sun Equatorial Horizontal Parallax08.8"
Moon Right Ascension11h58m55.2s
Moon Declination+00°23'45.5"
Moon Semi-Diameter15'07.6"
Moon Equatorial Horizontal Parallax0°55'30.9"
ΔT55.7 s

Eclipse season

This eclipse is part of an eclipse season, a period, roughly every six months, when eclipses occur. Only two eclipse seasons occur each year, and each season lasts about 35 days and repeats just short of six months 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.
September 23
Descending node
October 7
Ascending node
Annular solar eclipse
Solar Saros 134		Penumbral lunar eclipse
Lunar Saros 146

Related eclipses

Eclipses in 1987

Metonic

Tzolkinex

Half-Saros

Tritos

Solar Saros 134

Inex

Triad