Central Bureau for Astronomical Telegrams
IAUC 4665: Occns BY NEPTUNE; 1987A
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Circular No. 4665
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
OCCULTATIONS BY NEPTUNE
B. Sicardy, Observatoire de Paris, Meudon, writes: "Three
stellar occultations by Neptune were observed on Aug. 2, 25, and
Sept. 12. The Aug. 2 occultation (No. N49 of Mink and Klemola 1985,
A.J. 90, 1894) was observed by P. Bouchet, E. Matamoros, F. Roques,
B. Sicardy, and R. Vega using the 1-m and 3.6-m telescopes of the
European Southern Observatory (La Silla) at 2.2 microns. Recording
was made during Aug. 2.006-2.088 and 2.174-2.292 UT at both
telescopes. The occultation by the planet lasted from 5h15m30s to
5h57m30s (half-light times). The Aug. 25 occultation (No. n1038 of
Nicholson et al. 1988, A.J. 95, 562) was observed by K. Barton, A.
Barucci, B. Grundseth, and R. McLaren with the Canada-France-Hawaii
3.6-m telescope (Mauna Kea) during Aug. 25.252-25.471. The occultation
by the planet lasted from 8h52m25s to 9h57m50s. The Sept. 12
occultation (No. N51 of Mink and Klemola, and No. n1040 of Nicholson
et al.) was observed by L. Capoani, F. Colas, P. Richaud, F. Roques,
and R. Vitry with the 1.93-m telescope of Haute Provence Observatory
at 2.2 microns, and by C. Duthu, C. Hubert, J. Lecacheux, S. Pau, and
B. Sicardy with the 2-m telescope of Pic du Midi Observatory at 0.9
micron. Observations were recorded during Sept. 12.866-12.934 at
Haute Provence, and Sept. 12.783-12.940 at Pic du Midi. The emersion
of the star from behind the planet occurred at about 21h10m (Haute
Provence) and 21h10m30s (Pic du Midi). A central flash was observed
at Pic du Midi during 19h00m30s-19h06m, with two maxima at 19h01m15s
and 19h05m, amounting to 18 and 35 percent of the unocculted stellar
flux, respectively. None of the observations above shows conspicuous
evidence for secondary events due to ring-like objects in Neptune's
Roche limit. The upper limit of the detectable equivalent width of
such objects is about 20 km for the Aug. 2 observation, 2 km on Aug.
25, and 2 km on Sept. 12."
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
Visual magnitude estimates (cf. IAUC 4633): Sept. 26.42 UT, 9.5
(P. Williams, Heathcote, N.S.W.); 28.45, 9.5 (Williams); Oct. 5.54,
9.5 (Williams); 6.43, 9.6 (Williams); 8.39, 9.6 (Williams); 9.55, 9.5
(Williams); 17.48, 10.2 (D. A. J. Seargent, The Entrance, N.S.W.).
1988 October 17 (4665) Daniel W. E. Green
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