Central Bureau for Astronomical Telegrams
IAUC 5330: PERSEID METEORS AND P/SWIFT-TUTTLE
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Read IAUC 5331
Circular No. 5330
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM EASYLINK 62794505
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
PERSEID METEORS AND PERIODIC COMET SWIFT-TUTTLE
D. Levy and P. Jedicke report that their observations from
Springfield, VT, through clouds, showed what was obviously a rather
intense display of Perseids on Aug. 12.3 UT, with 15 meteors, one as
bright as mag -8, being noticed in an interval of 40 min. Yamamoto
Circ. No. 2170 quotes a report from Y. Taguchi, Osaka, to the effect
that observations by a group at an altitude of 1720 m near the Kiso
Observatory gave the following individual hourly rates for the
midtimes specified: Aug. 12.62 UT, 64; 12.66, 352; 12.70, 62; the
corrected ZHR for the middle hour (Lsun = 138.86, equinox 1950.0) was
more than 400. P. Aneca, B. de Pontieu, J. Deweerdt and J.
Vanwassenhove, Vereniging voor Steerenkunde, Brussels, observing in
very good conditions (limiting mag 6.2-6.5) at Haute Provence,
individually recorded between 280 and 320 meteors during two hours
surrounding Aug. 13.08 UT; correction only for the radiant height yields
a ZHR of up to 200. Observations by Levy and Jedicke on Aug. 13.3 UT,
this time under clear skies south of Montreal, showed far fewer
meteors than the night before.
Although it is generally presumed that the associated comet,
P/Swift-Tuttle (1862 III), passed perihelion unobserved around 1981
+/- 2, the possibility that P/Swift-Tuttle was identical with comet 1737 II
(Kegler) and that it may therefore return in late 1992 is perhaps
enhanced by this year's very strong Perseid display. The nominal
prediction (Marsden 1973, A.J. 78, 662) is T = 1992 Nov. 25.85 ET,
Peri = 153.05, Node = 138.74, i = 113.45 (equinox 1950.0), q = 0.9582
AU, e = 0.9633. Because of nongravitational effects, the uncertainty
in T could be as much as +/- 2 months, and this affects the ephemeris (below)
through mid-October by +/- 2 degrees, mainly in declination. The
predicted magnitude is little more than a guess.
1991 ET R.A. (1950) Decl. Delta r m2
Sept.11 9 36.73 +31 22.6
21 9 43.10 +31 32.2 6.022 5.324 21.2
Oct. 1 9 49.23 +31 48.5
11 9 55.01 +32 13.2 5.589 5.143 20.8
21 10 00.26 +32 47.7
31 10 04.83 +33 33.9 5.101 4.960 20.5
Nov. 10 10 08.51 +34 33.7
20 10 11.03 +35 48.8 4.591 4.774 20.1
30 10 12.10 +37 20.9
Dec. 10 10 11.33 +39 11.0 4.097 4.584 19.7
1991 August 28 (5330) Brian G. Marsden
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