 | THE HISTORY OF THE FORMER HAN DYNASTY The history of the former Han dynasty |  |
APPENDIX
ECLIPSES DURING THE REIGN OF EMPEROR CH'ENG
i. In Chien-shih, III, xii (the twelfth month), on the day mou-shen,
the first day of the month, a solar eclipse is recorded (HS 10: 4a; Han-chi
24: 6b). HS 27 Cb: 15a adds that it was nine degrees in the constellation
Wu-nü.
P. Hoang, Concordance des chronologies néoméniques, equates this date
with the julian Jan. 5, 29 B.C., for which day Oppolzer, Canon der
Finsternisse, calculates his solar eclipse no. 2810. He charts the moon's
umbra as passing thru Indo-china and Formosa. He calculates the sun
as in long. 283° = 284° R.A. The principal star of Wu-nü, ε Aquarii, was
then in 284° R.A.
Between this and the preceding recorded eclipse, no solar eclipses were
visible in China.
ii. In Ho-p'ing I, iv, on chi-hai, the last day of the month, a second
solar eclipse is recorded. (HS 10: 5a, b; 27 Cb: 15b; Han-chi 24: 11a).
The "Annals" say it was total; the "Treatise" says, however, "It was not
completely [total, but] like a hook. It was 6 degrees in [the constellation]
Tung-ching." Liu Hsiang4's interpretation, in the same passage, however
says it was total. The Han-chi here copies the "Treatise," but
writes yi for chi.
Hoang equates this date with June 19, 28 B.C., for which Oppolzer
calculates his solar eclipse no. 2813. Calculation of this eclipse according
to the method in Neugebauer, Astronomische Chronologie, shows that it
reached a magnitude of 0.96 (sun's diameter = 1.00) at Ch'ang-an, and
that the broad path of totality ran only 3° or less south of Ch'ang-an.
Hence the recording in the "Treatise" came from a record made in
Ch'ang-an, whereas that in the "Annals" was taken from reports from
places outside the capital, confirming the conclusion reached in connection
with the eclipse of July 17, 188 B.C. (cf. HFHD I, p. 189). The
calculated longitude of the sun was 84° = 83° R.A. The first star in
Tung-ching, μ Gem, was then in 65° R.A. There is thus a discrepancy of
about ten degrees between the location of the sun at the time of eclipse
and that stated in this record.
In the two years between this and the preceding recorded eclipse, no
solar eclipses were visible in China.
iii. In Ho-p'ing III, viii, on yi-mao, the last day, a third eclipse is
recorded (HS 10: 5b; 27 Cb: 15b; Han-chi 25: 1a). The "Treatise"
Hoang equates this date with Oct. 23, 26 B.C., for which Oppolzer
calculates his solar eclipse no. 2820. He charts the moon's umbra as
passing thru Szechuan and Formosa, and calculates the sun as in longitude
207° = 205° R.A. The principal star of Fang, π Scr, was then
in 210° R.A.
In the two years between this and the preceding recorded eclipse, no
solar eclipses were visible in China.
iv. In Ho-p'ing IV, iii, on kuei-ch'ou, the first day, a fourth eclipse of
the sun is recorded (HS 10: 6a; 27 Cb: 15b; Han-chi 25: 5b). The
"Treatise" adds that it was in the constellation Mao.
Hoang equates this date with Apr. 18, 25 B.C., for which Oppolzer
calculates his solar eclipse no. 2821. He charts the moon's umbra as
passing thru Siam and the Philippines, and calculates the sun's longitude
as 25° = 23° R.A. The principal star of Mao, η Tauri (Alcyone), the
brightest star in the Pleiades, was then in 28° R.A.
In the six months between this and the preceding recorded eclipse, no
solar eclipse occurred.
v. In Yang-so I, ii, on ting-wei, the last day, a solar eclipse is recorded
(HS 10: 6b; 27 Cb: 15b; Han-chi 25: 7a). The "Treatise" adds that it
was in the constellation Wei4.
Hoang equates this date with Apr. 7, 24 B.C., for which Oppolzer
calculates his solar eclipse no. 2823. He charts the moon's umbra as
passing thru northern Siberia to the Arctic Ocean and calculates the sun's
longitude as 15° = 13° R.A. The principal star of Wei4, 35 Arietis, was
then in 13° R.A.
In the year between this and the preceding recorded eclipse, no solar
eclipses were visible in China.
vi. HS 27 Cb: 15b says, "In Yung-shih I, ix, on ting-szu, the last day,
there was an eclipse of the sun." The "Annals" (ch. 10) do not note this
eclipse. (Han-chi 26: 6a has this notation with the day yi-szu.)
Hoang equates this date with Nov. 1, 16 B.C., for which Oppolzer
calculates his solar eclipse no. 2846. It was merely partial; calculation
shows that at Ch'ang-an it reached a magnitude of only 0.08 at 4:29
p.m. local time. It was better visible farther north; at the present
Peiping it reached a magnitude of 0.15 at 4:51 p.m. local time.
The "Treatise" and the Han-chi say, after the record of this eclipse,
"[Heaven] caused the capital alone to know of it, the kingdoms in the
four [directions] did not perceive it." The small magnitude of the eclipse
in north China effectually prevented its being perceived except by special
etc., so that unless people were looking for an eclipse, it would hardly
have been perceived. It accordingly appears very likely that during
this reign, at least, the court astronomers were on the look-out for solar
eclipses, and used special means to perceive them. There was an Office
for Watching the Heavens (cf. Glossary, s.v.).
Between these eclipses of 24 and 16 B.C., Oppolzer calculates 22 solar
eclipses, none of which was visible in China.[1]
vii. In Yung-shih II, ii, on yi-yu, the last day, a solar eclipse is recorded
(HS 10: 11b; 27 Cb: 15b; Han-chi 26: 6a).
Hoang equates this date with Mar. 29, 15 B.C., for which Oppolzer
calculates his solar eclipse no. 2847. He charts the path of the moon's
umbra as passing thru the present outer Mongolia.
The "Treatise" and the Han-chi continue, "[Heaven] caused the four
quarters all to perceive [this eclipse], whereas in the capital it was cloudy
and overcast." Here is definite proof that eclipses were reported to
the capital from other localities and were recorded by the court
astronomers.
In the seven months between this and the preceding recorded eclipse,
no solar eclipses occurred.
viii. In Yung-shih III, i, on chi-mao, the last day, an eighth solar
eclipse is recorded (HS 10: 12b; 27 Cb: 16a; Han-chi 26: 10a. The latter
book reads yi for the HS's chi.)
Hoang equates this date with Mar. 18, 14 B.C., for which Oppolzer
calculates his solar eclipse no. 2849. This eclipse reached a magnitude
of 0.43 at 3:40 p.m., local time at Ch'ang-an.
In the year between this and the preceding recorded eclipse, no solar
eclipses were visible in China.
ix. In Yung-shih IV, vii, hsin-wei, the last day, a ninth solar eclipse
is recorded (HS 10: 13b; 27 Cb: 16a; Han-chi 26: 12a). Hoang equates
this date with Aug. 31, 13 B.C., for which Oppolzer calculates his solar
eclipse no. 2852. He charts the path of the eclipse as passing through
In the year and a half between this and the preceding recorded eclipse,
no solar eclipses were visible in China.
x. HS 10: 13b & 27 Cb: 16a also record another solar eclipse in Yüan-yen
I, i, chi-hai, the first day. The Han-chi does not list this eclipse.
Hoang equates this date with Jan. 26, 12 B.C., for which Oppolzer calculates
his solar eclipse no. 2853. This eclipse was merely partial; calculation
shows that at Ch'ang-an it reached only a magnitude of 0.07 at 7:14
a.m., local time, beginning at 7:35 a.m. and ending at 8:42 a.m., local
time. Sunrise was at 6:56 a.m. An eclipse of such a slight magnitude
and lasting only 67 minutes could only have been perceived by an
astronomer who was on the look-out for eclipses.
In the five months between this and the preceding recorded eclipse,
no solar eclipses occurred.
Except for six eclipses, all others are plainly shown to be invisible by the data in
Oppolzer, either by the data for the track of the moon's umbra, or by the value given
for γ. The remaining six were calculated and found invisible. That of Mar. 27, 23 B.C.
was visible only at high latitudes, except in the Atlantic Ocean. That of Aug. 22, 23 B.C.
was also visible only at high latitudes; at the longitude of Ch'ang-an it was visible only
north of lat. 45°. That of Feb. 5, 21 B.C. was visible in India and in the Pacific Ocean,
but not in China. That of June 10, 19 B.C. was visible only in western Siberia. That of
Nov. 23, 18 B.C., was invisible north of about lat. 19°. That of Apr. 9, 16 B.C. was
invisible south of lat. 60°.
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