Central Bureau for Astronomical Telegrams
IAUC 4376: 1987D; 1987A
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Circular No. 4376
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 1987D IN MCG +0-32-01
J. Schombert provides the following precise position of the
SN, measured from the Palomar Sky Survey II plate: R.A. = 12h17m07.4,
Decl. = +2 21'06" (equinox 1950.0), or 11" east and 24" south of the
galaxy's center. Spectra obtained with the 5.1-m Palomar reflector
on Apr. 27 by J. Gunn, M. Schmidt, and D. Schneider confirm that
this is a type-I SN, 10 to 20 days after maximum light.
M. Rosa, European Southern Observatory, reports: "A spectrum
of SN 1987D has been obtained at the ESO 1.5-m telescope (range
365-700 nm, resolution 0.8 nm) on Apr. 28.02 UT. The following
wavelengths have been corrected for the redshift of the parent galaxy,
determined to be about 0.077 from H alpha of an H II region near the
nucleus. Strong, broad emission is present on the blue continuum
at 395, 408-425, 457, 519, and 561 nm. Weaker emission occurs at
479, 586, and (rather narrow) 492 nm. There is prominent absorption
at 615 nm. The object is thus type Ia near maximum phase."
G. M. Hurst, Basingstoke, England, provides the following
magnitude estimates by himself (visual) and A. Young, Burwash (
photovisual): Apr. 22.89 UT, 13.2 (Hurst); 22.92, 13.3 (Young); 23.87,
13.5 (Hurst); 23.88, 13.4 (Young); 25.87, 13.4 (Hurst).
This supernova was also inadvertently given the designation
1987G on IAUC 4375.
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
With reference to the companion reported on IAUC 4341 and
subsequent remarks on IAUC 4343 and 4348, S. G. Djorgovski, Center for
Astrophysics, informs us that new data analysis confirms the existence
of a stellar object 1".80 from the supernova in p.a. 235 deg.
The object is seen in a narrow band containing the [O II] 372.7-nm
emission line but not seen in broad-band U images obtained by
Walker and Suntzeff. A possible explanation is that the object is
a compact H II region. This is supported by Sun's (IAUC 4343)
detection of 372.7-nm emission from the southern limb of the supernova.
Djorgovski adds that further studies of this object would be
most valuable, as it may provide valuable diagnostics when the
supernova light and shock waves reach it.
Visual magnitude estimates: Apr. 26.42 UT, 2.9 (G. Garradd,
Tamworth, N.S.W.); 26.51, 3.0 (R. H. McNaught, Siding Spring
Observatory); 27.46, 3.0 (McNaught).
1987 April 28 (4376) Daniel W. E. Green
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