Central Bureau for Astronomical Telegrams
IAUC 4338: 1987A
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Circular No. 4338
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
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
M. Koshiba, International Center for Elementary Particle
Physics, University of Tokyo, reports on behalf of the Kamiokande-II
collaboration with Niigata University and the University of
Pennsylvania: "Kamiokande-II observed the neutrino (anti-neutrino)
burst from SN 1987A. The signal consists of 11 neutrino (anti-
neutrino)-produced electron (positron) events in the 2140-tonne
water Cerenkov imaging detector situated 2700 Hg cm-2 underground
in Kamioka mine, Gifu. The events were observed during an interval
of 13 s on Feb. 23.316 UT. The observed electron (positron)
energy interval was from the 7.5 MeV threshold to 36 MeV. The
first two events point back to the LMC within 18 +/- 18 and 15 +/-
27 deg. No events were recorded around Feb. 23.12 UT, the time of
the reported Mont Blanc detection (IAUC 4332)."
There is obviously much interest in prediscovery photographs
that may have been taken of the supernova field between Feb. 23.1
and 23.4 UT, although it seems unlikely that there would have been
many observers between Chile and New Zealand. M. Thomas and S.
Ryder, Beverley-Begg Observatory, Dunedin, inform us that a 10-min
color exposure (hypersensitized Konica SR1600) on Feb. 23.54 UT
showed the object considerably brighter than SAO 249334 (V = 7.5).
F. Steeman, H.-E. Schwarz and P. Monderen report the following
Walraven photometry, obtained at the European Southern Observatory:
Feb. 25.04 UT, V = 4.65, V-B = -0.19, B-U = -0.10, U-W
= -0.12, B-L = -0.10; 26.05, 4.55, -0.25, -0.30, -0.15, -0.25;
27.07, 4.47, -0.40, -0.66, -0.59, -0.49; 28.10, 4.46, -0.56, -1.28,
-1.05, -0.73; Mar. 2.08, 4.50, -0.84, -2.20, -1.19, -1.11; 4.07,
4.46, -1.10, -2.68, -1.22, -1.27; 5.10, 4.42, -1.24, -2.86, -1.15,
-1.35; 6.04, 4.40, -1.36, -2.95, -1.26, -1.40; 9.07, 4.32, -1.68,
-2.99, -1.28, -1.51. Uncertainties are +/- 0.01 (+/- 0.02 in U-W).
The Co I lines at 340-345 nm just fall in the U band and the Ca II
316-318-nm lines in the W band; these lines have so far not been
observed. The V-W color behavior (a very rapid decrease, then
flattening out after Mar. 2) correlates well with the long-wave
length IUE data (IAUC 4327). The W band is the only photometric
band to give a link between groundbased photometry and IUE data.
Visual magnitude estimates: Mar. 9.40 UT, 4.2 (D. Seargent,
The Entrance, N.S.W.); 9.41, 4.4 (R. H. McNaught, Coonabarabran,
N.S.W.); 9.46, 4.2 (T. Beresford, Adelaide, South Australia).
1987 March 10 (4338) Brian G. Marsden
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