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IAUC 4557: N Vul 1987; 1986l; 1987A; N Her 1987

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                                                  Circular No. 4557
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


NOVA VULPECULAE 1987
     R. D. Gehrz, Department of Astronomy, University of Minnesota;
and T. Hayward, Department of Physics and Astronomy, University of
Wyoming, communicate the following infrared magnitudes obtained
with the 2.34-m Wyoming Infrared Telescope on Feb. 24 UT:  [2.3 microns]
= +5.8, [3.6 microns] = +2.4, [4.9 microns] = +0.9, [7.8 microns] = -0.4,
[8.7 microns] = -0.7, [9.8 microns] = -0.8, [10.3 microns] = -1.0, [11.6
microns] = -1.4, [12.5 microns] = -1.4, [18 microns] = -1.5.  These
magnitudes can be fitted by a 600-deg blackbody curve and indicate the
presence of a dust shell, probably containing carbon.  Based on recent
infrared photometry, the flux from the dust shell appears to be declining,
suggesting that the dust is past its formation maximum and has been cooling.
     Visual magnitude estimates (cf. IAUC 4533, 4544):  Feb. 14.20
UT, 15.4 (M. Verdenet, Bourbon-Lancy, France); 21.17, 15.7 (Verdenet);
26.21, 15.4 (S. Lubbock, Bridgend, Wales).


COMET WILSON (1986l)
     Z. Sekanina, Jet Propulsion Laboratory, California Institute
of Technology, reports:  "Analysis of the available separations
between the two nuclei on Feb. 13-22 (IAUC 4552, 4555) indicates that
the comet broke up 132 +/- 7 days after perihelion, or about 1987
Aug. 31, at a heliocentric distance of 2.3 AU (mean residual of the
fit 0".22).  The differential nongravitational deceleration of the
secondary nucleus is 63 +/- 11 units of 10E-5 solar attraction.
Following is an ephemeris for 0h ET (equinox 1950.0):  Feb. 29, position
angle 116 deg, separation 10".6; Mar. 20, 115 deg, 12".0; Apr. 9,
116 deg, 12".5; Apr. 29, 117 deg, 12".7."


SUPERNOVA 1987A IN THE LARGE MAGELLANIC CLOUD
     Visual magnitude estimates by A. C. Beresford, Adelaide, South
Australia:  Feb. 20.48 UT, 7.0; 21.48, 7.0; 22.51, 6.9; 23.47, 6.9;
24.58, 6.8; 25.44, 6.8; 26.47, 6.9; 28.57, 6.8; 29.45, 6.9.


NOVA HERCULIS 1987
     Visual magnitude estimates (cf. IAUC 4487):  1987 Nov. 15.80
UT, 13.4 (A. Boattini, Piazzano, Italy); 21.76, 13.6 (Boattini);
1988 Feb. 14.21, 13.5 (M. Verdenet, Bourbon-Lancy, France);
19.2, 13.4 (Verdenet); 21.2, 13.4 (Verdenet).


1988 February 29               (4557)            Daniel W. E. Green

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