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IAUC 4399: V348 Sgr; 1986l; 1987A; U Sco

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                                                  Circular No. 4399
Central Bureau for Astronomical Telegrams
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

     M. W. Feast, South African Astronomical Observatory, reports
that observations by D. Pollaco show that this unique variable
faded from V = 12.3 on May 19 to V = 15.5 on May 26.

     T. Brooke, R. Knacke, T. Owen and A. Tokunaga report their
detection at the NASA Infrared Telescope Facility on May 24 of
emission features at 2.8 and 3.4 microns.  The band positions and
shapes closely resemble the unidentified emission features
discovered in the spectrum of P/Halley in 1986.

     G. Sonneborn, M. Crenshaw, IUE Observatory, Goddard Space
Flight Center; and R. Kirshner, Center for Astrophysics, report:
"Recent observations with the IUE satellite show that the
ultraviolet flux increase (cf. IAUC 4377) has slowed down; the near-
ultraviolet flux levels are now nearly constant.  A slow increase
in the far-ultraviolet flux has been detected between 180 and 200
nm.  However, the optical brightness of the supernova, as measured
by the IUE fine-error-sensor, reached a maximum near May 20 and
has started to decline.  The near-ultraviolet spectrum has not
changed qualitatively from previous reports: broad features at
285.0, 310.5 and 323.0 nm, with FWHM of 5, 7 and 4 nm and peak flux
levels of 1.4, 1.2 and 3.0 (in units of 10**-12 erg s-2 cm-1 A-1),
respectively.  The features at 241 and 262 nm, with FWHM 4 and 3
nm and peak flux levels of 0.18 unit, are sharply peaked and more
extended to the red than to the blue side of the emission peak.
These features may be redshifted emission of Fe II multiplets 1 and
2.  At shorter wavelengths there are two features at 183.5 and
195.0 nm (FWHM 3 nm and peak flux 0.060 unit) which stand out above
the broader continuum flux increase between 180 and 200 nm.  No
flux increase has been detected in the 115-180 nm range.  The
estimated fine-error-sensor V mag was 3.0 at maximum brightness on May
20 +/- 2 and had dropped slightly to 3.10 on May 28.8."

     Further visual magnitude estimates by R. H. McNaught,
Coonabarabran, N.S.W.: May 26.58 UT, 14.1; 28.79, 14.4.

1987 May 30                    (4399)              Brian G. Marsden

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