Central Bureau for Astronomical Telegrams
IAUC 4391: 1987A; FY CMa; 1986l
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Circular No. 4391
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
S. J. Marcher, W. P. S. Meikle, and B. L. Morgan, Imperial
College, London, telex: "We report further observations (cf. IAUC
4369) of SN 1987A at the Anglo-Australian Telescope on Apr. 14.42-
14.45 UT using the Imperial College speckle interferometer. Filter
passbands were 1.0 nm, centered on 587.6 nm and 658 nm. At 658.5
nm, a source was detected at p.a. 196 deg +/- 2 deg. Preliminary
examination of the data suggests that the source is about 3 mag fainter than
the SN at this wavelength. At 587.6 nm, there is marginal evidence
for the presence of a source at the same position but of fainter
magnitude. To within the quoted errors, the position of the source
is the same as that reported on IAUC 4382. Observations of a nearby
reference star (BS 2015), made immediately before and after the
SN observations, yielded autocorrelation functions corresponding to
an unresolved source."
Photoelectric photometry by S. O. Kepler, Instituto de Fisica,
Universidad Federal Rio Grande do Sul (0.5-m telescope): May 10.96
UT, V = 3.29, B = 4.78 (+/- 0.05).
FY CANIS MAJORIS
G. J. Peters, Space Sciences Center, University of Southern
California, writes: "The spectrum of the Be star FY CMa (HR 2855)
has undergone a striking change in just 12 days. Observations with
the Coude Feed Telescope (+ TI3 CCD) at Kitt Peak National Observatory
reveal that between Apr. 20 and May 2 the violet lobe of the
centrally-reversed H-alpha feature increased in strength by 35 percent
(violet, red lobe intensities with respect to continuum: I(V)/I(cont)
about 2.5, I(R)/I(cont) about 1.8), while He I (667.8 nm), which previously
displayed a simple absorption profile with very weak double emission,
developed a structured, inverse P-Cyg profile with a violet
emission lobe of about 1.2 I(cont) and a central core (velocity about -70
km/s). Steady nightly variations were seen in the He I feature
through May 6. Further observations are urged during the next few
weeks before the star becomes unobservable for the season."
COMET WILSON (1986l)
Further total visual magnitude estimates: May 1.45 UT, 4.8
(Wolf, 0.20-m refl.); 3.48, 5.2 (G. Garradd, Tamworth, N.S.W.,
naked eye); 6.46, 4.5 (Wolf); 11.35, 5.0 (Wolf).
1987 May 14 (4391) Daniel W. E. Green
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