Central Bureau for Astronomical Telegrams
IAUC 4328: 1987A
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Circular No. 4328
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
J. R. Walsh and J. A. Bailey, Anglo-Australian Observatory;
and K. Ogura, Kogukakuin University, Tokyo, report: "
Spectropolarimetry was obtained on Feb. 27.55 UT with the Pockels cell
spectropolarimeter on the AAT. Over the wavelength range 350-530
nm the polarization is 0.8 to 1.0 percent in p.a. 35 , confirming
previous results. Any structure in the polarization across the P-
Cyg profiles was less than the measurement errors. At H beta we measure
1.08 +/- 0.10 percent on the emission peak and 0.93 +/- 0.14 percent
on the absorption trough. At H gamma the corresponding figures
are 0.83 +/- 0.14 and 0.75 +/- 0.20 percent."
A. Rodgers and P. Harding, Mt. Stromlo Observatory, telex:
"We obtained high signal-to-noise spectra between 300 and 800 nm
during Feb. 26-Mar. 1 with resolution 40 km/s. The spectrum
consists of continuum with P-Cyg profiles of Balmer lines, the total
profile width being about 66 nm. At H alpha the emission peak amounts to
10 percent of the continuum. Blueshifted absorption components of
all the lines increase in depth with time up to Mar. 1. The FWHM
of the absorption component of H alpha is 17 nm with a residual central
depth of 45 percent on Mar. 1. The center of the ill-defined H alpha
profile is at 636.4 nm. The centers of H beta, gamma and delta are at 473.3,
423.5 and 399.0 nm, respectively. A broad absorption feature at
391.0 nm is probably a blend of higher Balmer lines and He I 388.9
nm. On Mar. 1 the spectrum resembled neither a type I nor a type
II supernova. Galactic and LMC components of interstellar K, H
and D lines are visible."
N. Suntzeff, Cerro Tololo Interamerican Observatory, confirms
that SN 1987A is reddening rapidly in the blue, nightly spectrophotometry
with the 0.40-m telescope by J. Matthews, M. Pastoriza,
T. Storlhi-Bergmann, R. Gonzalez and M. Hamuy also indicating rapid
reddening shortward of 500 nm: Feb. 25.111, V = 4.63, B-V = +0.05,
U-B = -; 25.221, 4.57, +0.02, -; 26.040, 4.49, +0.16, -; 26.169,
4.50, +0.21, -; 26.183, 4.52, +0.20, -; 26.236, 4.52, +0.28, -;
27.065, 4.45, +0.38, -0.24; 27.085, 4.46, +0.37, -0.22; 27.095,
4.47, +0.38, -0.21; 28.058, 4.48, +0.47, +0.38; 28.135, 4.49,
+0.47, +0.39; 28.199, 4.43, +0.53, +0.39; Mar. 1.031, 4.46, +0.65,
+0.78; 1.072, 4.45, +0.64, +0.78; 1.140, 4.50, +0.68, +0.79; 1.197,
4.50, +0.68, +0.80; 2.022, 4.50, +0.76, +1.06; 2.082, 4.45, +0.80,
+1.06; 2.141, 4.52, +0.78, +1.08; 2.195, 4.52, +0.80, +1.06.
1987 March 3 (4328) Brian G. Marsden
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