Central Bureau for Astronomical Telegrams
IAUC 4611: Occn BY PLUTO; 1987p; 1987A
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Circular No. 4611
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
TWX 710-320-6842 ASTROGRAM CAM Telephone 617-495-7244/7440/7444
MARSDEN or GREEN@CFA.BITNET MARSDEN or GREEN@CFAPS2.SPAN
OCCULTATION BY PLUTO
Pluto was predicted to occult a star of mag 13 on June 9 for
observers in the Pacific (Mink and Klemola 1985, A.J. 90, 1894); the
corresponding occultation by Pluto I (Charon) would have taken place
off the south pole of the earth.
Indirect reports have been received of observations by J. L.
Elliot and E. W. Dunham, Massachusetts Institute of Technology, from
the Kuiper Airborne Observatory, located some 5500 km south of Hawaii.
Disappearance and reappearance during the 80-s event at 10h37m UT were
gradual, suggesting the presence of an atmosphere. The event was also
observed by R. L. Millis, Lowell Observatory, from a point north of Brisbane.
G. L. Blow, Carter Observatory, reports: "The event was observed
at the Black Birch outstation (Long. = +173D48'13".04, Lat. =
-41D44'55".85, Alt. = 1396 m) by J. Priestley and myself using the
0.41-m f/13.5 reflector. Monitoring was carried out with no filter
and an EMI 9813B phototube, approximately 12" aperture and
1.0-s integrations. A smooth decline of about 1 mag was observed
between about 10h38m14s and 10h39m05s UT. A smooth rise followed
immediately until 10h39m55s UT, when the count rate again began to
decline (possibly due to the star's proximity to the edge of the
aperture). Data were also obtained at the Mount John and Auckland
Observatories."
D. J. Tholen, University of Hawaii, reports that monitoring by M.
Buie, J. Spencer, D. Schleicher and himself with four telescopes at
Mauna Kea showed no occultation event at that site.
Cloudy weather seems to have prevented observations in
southeastern Australia and at the Perth Observatory.
PERIODIC COMET BORRELLY (1987p)
Total visual magnitude estimates: Apr. 9.33 UT, 12.4 (D. Levy,
Mt. Lemmon, AZ, 1.5-m reflector; tail 5' in p.a. 350 deg);
12.17, 11.8 (R. Keen, Mt. Thorodin, CO, 0.32-m reflector); 19.24, 12.6
(A. Hale, Las Cruces, NM, 0.41-m reflector).
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
Visual magnitude estimates by A. C. Beresford, Adelaide, South
Australia: May 24.39 UT, 7.7; 25.39, 7.8; June 2.38, 7.8; 8.39, 8.0.
1988 June 11 (4611) Brian G. Marsden
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