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IAUC 5545: N Cyg 1992; AM Her

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                                                  Circular No. 5545
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
Postal Address: Central Bureau for Astronomical Telegrams
Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
Telephone 617-495-7244/7440/7444 (for emergency use only)
TWX 710-320-6842 ASTROGRAM CAM     EASYLINK 62794505
MARSDEN@CFA or GREEN@CFA (.SPAN, .BITNET or .HARVARD.EDU)


NOVA CYGNI 1992
     J. L. Hora, University of Hawaii; L. K. Deutsch and H. M.
Butner, Ames Research Center, NASA; W. F. Hoffmann, University of
Arizona; G. G. Fazio, Harvard-Smithsonian Center for Astrophysics;
and K. Shivanandan, Center for Advanced Space Sensing, communicate:
"We report imaging of Nova Cyg 1992 with the UA/SAO/NRL Mid-Infrared
Array Camera (scale 0".67/pixel; camera noise equivalent flux
density 10 mJy arcsecE-2 at 11.7 microns in a 5-min on-source
integration) at the NASA Infrared Telescope Facility.  Images were
obtained at about 30-min intervals, starting at the following times
with respective wavelengths, bandpasses, and flux levels (using the
infrared standard star gamma Aql) from preliminary analysis:  June
3.62 UT, 12.5 microns, 1.16 microns, 4.09 Jy; 5.56, 8.8, 0.87,
1.16; 5.60, 11.7, 1.13, 1.58.  The 12.5-micron flux includes
emission from the [Ne II] line at 12.8 microns.  A comparison of the
profiles of gamma Aql and Nova Cyg yields an upper limit of 0".25
+/- 0".20 for the FWHM size of the nova.  A scaled stellar profile
was subtracted from the images of Nova Cyg to look for low-level
extended emission; the upper limits for extended emission given by
the residual images are 36 mJy at 8.8 and 12.5 microns, and 27 mJy
at 11.7 microns."


AM HERCULIS
     P. A. Mason and G. Chanmugam, Louisiana State University;
J. Raymond and S. Vrtilek, Harvard-Smithsonian Center for
Astrophysics; N. V. Borisov, Special Astrophysical Observatory;
N. M. Shakhovskoy, Crimean Astrophysical Observatory; I. L.
Andronov, Odessa State University; and C. Mauche, Lawrence
Livermore National Laboratory, report observations of AM Her in
its low state.  The IUE satellite observed AM Her for 8 hr
on June 3.  The ultraviolet spectra show none of the emission
lines that dominate high-state ultraviolet spectra.  Five-color
circular polarization measurements were made at the Crimean
Astrophysical Observatory 1.25-m telescope for 2.6 hr centered
on June 3.79 UT.  These observations are consistent with low-state
behavior with V = 15.1-15.5.  The circular polarization was
< 3 percent.  A spectrogram obtained June 4.84 with the Special
Astrophysical Observatory 6-m telescope shows evidence for a special
accretion event similar to the one observed in 1980 June; the
emission lines of H and He are much stronger than that typical
for the low state.  Spectra taken during one full orbital
period centered on June 4.94 show weak emission lines and three
broad components of Zeeman absorption.


1992 June 15                   (5545)            Daniel W. E. Green

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