Central Bureau for Astronomical Telegrams
IAUC 4457: 1987A; V1819 Cyg (N Cyg 1986)
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Circular No. 4457
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
R. Catchpole, South African Astronomical Observatory, telexes:
"Since it is possible that emission features, in particular
the CO fundamental band at 4.8 microns, may contribute a significant
fraction of the infrared excess in the M band reported by Allen,
Whitelock and Catchpole on IAUC 4453, spectroscopic observations
in this band are very important. An emission feature that may be
due to the CO first overtone at 2.3 microns is seen in a circular-
variable-filter spectrum taken by I. Glass on July 9."
M. Karovska, P. Nisenson, C. Papaliolios and C. Standley,
Center for Astrophysics, report: "The measurements of the diameter
of SN 1987A on IAUC 4450 were erroneously scaled by a factor
proportional to the observation wavelength. Correctly scaled values
follow. Apr. 2: 450 nm, 0".012 +/- 0".004, 600 AU, 13 500 km/s; 533
nm, 0".011 +/- 0".004, 550 AU, 12 500 km/s; 656 nm, 0".001 +/- 0".004, -,
-. June 1: 450 nm, 0".023 +/- 0".004, 1150 AU, 10 200 km/s; 533 nm,
0".018 +/- 0".004, 900 AU, 8000 km/s; 656 nm, 0".008 +/- 0".004, 400 AU,
3600 km/s; 775 nm, 0".015 +/- 0".004, 750 AU, 6700 km/s. As a
calibration of the accuracy of our measurements of the diameter of SN
1987A, we measured the diameter of Alpha Cen using speckle data
recorded at the CTIO 4-meter telescope with the PAPA speckle system.
Data were recorded at 533 nm with a 10-nm bandpass. Fitting the
Fourier transform of a uniform disk to the integrated power spectrum
gives an angular diameter of 0".009 +/- 0".002. This is very
close to the diameter of 0".0086 calculated by Blackwell and
Shallis (1977, M.N. 180, 177)."
Corrigendum. On IAUC 4452, in the second paragraph, the name
of the observer should read T. F. Flower.
Visual magnitudes: Sept. 23.56 UT, 5.6 (D. A. J. Seargent,
The Entrance, N.S.W.); 24.77, 5.4 (R. H. McNaught, Coonabarabran,
N.S.W.); 25.54, 5.4 (McNaught); 28.49, 5.5 (Seargent).
V1819 CYGNI (NOVA CYGNI 1986)
Visual magnitudes: Aug. 5.83, 12.9 (A. Boattini, Florence,
Italy); 17.92, 13.0 (J. Ripero, Madrid, Spain); 24.89, 13.6 (R.
Monella, Covo, Italy); 26.60, 12.7 (S. Sakuma, Kawasaki, Japan);
28.88, 13.0 (M. Verdenet, Bourbon-Lancy, France); 30.93, 13.0
(Boattini); 31.87, 13.0 (Ripero); Sept. 8.90, 13.0 (Boattini).
1987 September 29 (4457) Brian G. Marsden
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