Central Bureau for Astronomical Telegrams
IAUC 4359: 1987A
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Circular No. 4359
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
U. R. Rao, Indian Space Research Organization, Bangalore,
telexes photoelectric measurements obtained with a 0.35-m telescope
(comparison star HR 1859): Mar. 3.65 UT, V = 4.28, B-V = +1.25;
4.60, 4.41, +0.89; 5.61, 4.40, +1.04; 6.59, 4.54, +0.99; 7.59,
4.41, +0.97; 7.61, 4.40, +1.02; 8.58, 4.37, +1.14; 8.60, 4.39,
+1.26; 9.58, 4.44, +1.11; 12.60, 4.32, +1.12; 19.59, 4.39, -;
23.56, 4.23, +1.27; 24.58, 4.25, +1.11; 26.58, 4.16, +1.51.
A. C. Porter, California Institute of Technology, writes: "The
evidence for pre-maximum plateaux in the type-II supernovae 1940B
and 1941A (cf. IAUC 4329, 4334) is not substantial. The pre-maximum
light curve of SN 1941A includes only one point and one upper
limit (cf. HAC 522). The pre-maximum light curve of SN 1940B
contains no points, but it does contain five upper limits (HAC 576)
which were erroneously reported as magnitudes in Bull. Soc. Ast.
France 54, 185. This error is the source of reports of the
premaximum plateau. The present brightening of SN 1987A must
therefore be regarded as another peculiarity of this object, without
precedent among normal type-II SNe."
N. K. Rao, Indian Institute of Astrophysics, Bangalore,
reports: "Observations by B. N. Ashoka, K. K. Ghosh, S. Giridhar,
and S. G. V. Mallik using the Vainu Bappu Observatory 1-m and 0.75-
m telescopes show that emission around H-alpha has considerable
structure on Mar. 30.6 UT. A narrow, double-peaked emission feature
with a central absorption at 655.9 nm appears, with a peak-to-peak
separation of 1400 km/s. This feature was not present on Mar.
27.65. Another emission feature appears at 669 nm which may not be
related to H-alpha. The emission peak of the feature at 860 nm is
continuously shifting to the red (from 861.3 nm on Mar. 8 to 866.3 nm
on Mar. 30). It appears that there is contribution to this blend
from lines other than Ca II. We identify the absorption features
at 607.0, 619.8, and 639.0 nm with the Fe II multiplet 74, and at
735.8 nm with the Fe II multiplet 73."
Further visual magnitude estimates: Mar. 31.74 UT, 3.8 (J.
Campos, Durban, R.S.A.); Apr. 1.46, 3.7 (R. H. McNaught, Siding
Spring Observatory); 1.58, 3.8 (A. Beresford, Adelaide, South
Australia); 1.74, 3.8 (Campos); 2.46, 3.6 (McNaught); 3.44, 3.7 (G.
Garradd, Tamworth, N.S.W.); 4.46, 3.7 (McNaught); 4.63, 3.5
(McNaught); 5.40, 3.5 (D. A. J. Seargent, The Entrance, N.S.W.).
1987 April 6 (4359) Daniel W. E. Green
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