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IAUC 5574: 1992aq, 1992ar; 1992ao; N Sco 1992

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                                                  Circular No. 5574
Central Bureau for Astronomical Telegrams
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

     M. Hamuy, Cerro Tololo Interamerican Observatory; and J. Maza,
University of Chile, report the discovery by R. Antezana (University
of Chile) of two supernovae of mpg about 19; SNe 1992aq and
1992ar were found on 20-min unfiltered IIa-O plates taken on July
26.218 and 27.233 UT, respectively, by L. Wells and C. Muena (CTIO)
with the CTIO Curtis Schmidt telescope.  SN 1992aq is located about
2".3 east and 6".9 south of the nucleus of a galaxy at R.A. =
23h01m49s, Decl. = -37 36'.8, equinox 1950.0).  A spectrogram
(range 320.0-750.0 nm) of SN 1992aq was obtained by R. Williams
(CTIO) and Hamuy on Aug. 2.26 with the CTIO 4-m telescope, showing
that this is a type-Ia supernova near maximum light; the redshift
of the nucleus of the parent galaxy is 0.101.  SN 1992 ar (R.A. =
23h14m42s, Decl. = -44 55'.3, equinox 1950.0) is located at the
southern edge of a small group of three galaxies; its position is
1".5 west and 5".3 south of the eastern-most galaxy.  A spectrogram
(range 320-750 nm) of SN 1992ar, obtained by Williams and Hamuy on
Aug. 2.65 with the CTIO 4-m telescope, initially suggested that
this might be a type-Ia supernova about 5 weeks after maximum light,
but after examining spectra of the type-Ia supernova 1989B and the
type-Ic supernovae 1983V, 1987M, and 1990W, M. Phillips and Hamuy
both agree that SN 1992ar looks much more like a type-Ic event at
maximum light; the redshift of the nucleus of the eastern-most galaxy
is 0.145.  R. Aviles and R. C. Smith (CTIO) also obtained
confirming CCD images of both supernovae on Aug. 1.4 with the CTIO
0.9-m telescope.

SUPERNOVA 1992ao IN NGC 7637
     Hamuy also reports that a spectrogram (range 600-1000 nm) of
SN 1992ao was obtained with the CTIO 1.5-m telescope by R. Williams
and himself on Aug. 1.388 UT.  The only remarkable feature in this
spectrum is a broad (10 000 km/s FWHM) emission centered at 660.8
nm, probably due to H-alpha, atop an essentially featureless blue
continuum.  This would imply that this object is a type-II
supernova in an early stage.

     Further photometry by A. C. Gilmore, Mt. John University
Observatory (cf. IAUC 5567):  July 30.43 UT, V = 8.64 +/- 0.01, B-V =
+1.07 +/- 0.01, U-B = +0.02 +/- 0.01, V-R = +0.81 +/- 0.01, V-I =
+1.54 +/- 0.02.

1992 August 3                  (5574)            Daniel W. E. Green

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