Central Bureau for Astronomical Telegrams
IAUC 4518: 1987M; 1987A; 1987s
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Circular No. 4518
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 1987M IN NGC 2715
A. K. Uomoto, Physics Department, Johns Hopkins University,
writes: "I observed SN 1987M with the Kitt Peak 4-m reflector (+
Cryocam) and found it well on its way to becoming a supernebula.
Strong, broad emission lines of [O I] 630-636 nm and [Ca II] 729-
732 nm are seen superposed on a continuum that shows P-Cyg profiles
in He I 588 nm and possibly 502 nm. Spectrophotometric observations
of the emission line strengths and profiles, as well as the
decline of the continuum, are especially important during this
transition period because they can show the time-dependent geometry
of the explosion. The supernova is 4" east and 18" north of
the nucleus and 37".5 east and 27" south of a nearby star."
SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
P. Harvey, D. Lester and M. Joy, University of Texas at Austin,
report far-infrared photometry of SN 1987A, obtained on Nov.
22 with NASA's Kuiper Airborne Observatory in Christchurch, New
Zealand. An eight-channel linear-array photometer observed emission
of 7.7 +/- 0.6 Jy at 47 microns (25-micron bandwidth) and 4.9 +/- 0.4 Jy
at 95 microns (70-micron bandwidth) at the position of SN 1987A, with
absolute calibration uncertainties of +/- 15 percent at 47 microns and +/- 20
percent at 95 microns. No emission was seen by detectors offset by 10"-
30" from the position of SN 1987A at a (2 sigma) upper limit of 1.5 Jy
at each wavelength; this confirms that the measured flux originates
from SN 1987A. These flux levels, together with groundbased 10 micron
data, are more consistent with gaseous emission processes than
thermal dust emission. These observations represent the longest
wavelength detection of SN 1987A at this phase of its evolution.
Visual magnitude estimates by A. C. Beresford, Adelaide, South
Australia: Dec. 20.50 UT, 6.3; 21.46, 6.2; 23.48, 6.3.
COMET BRADFIELD (1987s)
D. Ketelsen, University of Arizona, reports an antitail 1
long in p.a. 240 deg on 30-min exposures with the 0.43-m Schmidt
telescope (hypersensitized, ulfiltered Kodak 2415 film) at the
Catalina Station on Dec. 21.12 and 22.15 UT. Sky conditions were
excellent on both nights, but the antitail was better defined on
Dec. 22. The main tail was at least 3.7 deg long.
Corrigendum. IAUC 4496, line 7, for N' = 1.6 read N' = -1.6.
1987 December 23 (4518) Brian G. Marsden
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