Central Bureau for Astronomical Telegrams
IAUC 5841: PERSEID METEORS 1993; 1992bt
The following International Astronomical Union Circular may be linked-to from your own Web pages, but must not otherwise be redistributed (see these notes on the conditions under which circulars are made available on our WWW site).
Read IAUC 5842
.dvi or
.ps format.
Circular No. 5841
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@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)
PERSEID METEORS 1993
Reports from numerous observers in Europe and North America
indicate that, although there was no meteor storm, impressive meteor
activity was observed from both continents, with a high percentage of
bright fireballs and enduring trains; J. Rao, observing from the
Mediterranean Sea, noted one fireball as bright as mag -10. S. Nakano
indicated unusually weak activity in Japan up to Aug. 11.8 UT.
Preliminary information compiled by M. Gyssens, International Meteor
Organization, from observations made in Croatia, Czech Republic,
Germany, Belgium, France and England, tentatively suggests a zenithal
hourly rate ZHR around 40 on Aug. 11.85, rising to perhaps
100 by Aug. 12.04, after which there was a more significant increase
until Aug. 12.13, when the ZHR may well have surpassed 300. M. Kidger
and others, observing from the Canary Islands, were indicating
ZHR about 350-400 during a 10-min interval around Aug. 12.13, dropping
closer to 100 during Aug. 12.14-12.18. D. W. E. Green and others,
observing under less satisfactory conditions in Massachusetts,
independently reported a peak around Aug. 12.13, with significantly
less activity during Aug. 12.17-12.21. In New Mexico, A. Hale
remarked that he seemed to be seeing the end of a period of activity
around Aug. 12.14, with a prevalence of bright, long-pathed meteors; as
the altitude of the radiant increased and conditions improved he noted
more normal activity until Aug. 12.37.
SUPERNOVA 1992bt IN NGC 3780
R. R. Treffers, B. Leibundgut and A. V. Filippenko, University of
California at Berkeley; and M. W. Richmond, Princeton University, report
the discovery of a probable supernova in NGC 3780 (R.A. = 11h36m38s,
Decl. = +56 33.0, equinox 1950.0), about 22" west and 0".5 north of the
galaxy's nucleus. The object was found during the Leuschner Observatory
Supernova Search, which uses an automated 0.76-m telescope equipped
with the Lawrence Berkeley Laboratory CCD camera. It is visible at R
approximately 16 on 1992 Dec. 19 but was not automatically
detected by the software because this was the first image of NGC 3780
obtained for the search. It is also visible at roughly the same brightness
in images taken on Dec. 22 and 25, 1993 Jan. 4, 11, 25 and Mar. 5.
By Mar. 31 the object seems to have faded about 0.8 mag. It could not
be detected to limiting mag 17.5 +/- 0.3 in images obtained
on Apr. 20 and later. The lightcurve suggests that the supernova was of
type II (plateau), but confirmation with a late-time spectrum is desirable.
1993 August 12 (5841) Brian G. Marsden
Read IAUC 5842
.dvi or
.ps format.
Our Web policy. Index to the CBAT/MPC/ICQ pages.
