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IAUC 3255: SN IN MCG -5-9-22; 1978 PA; 1978 P 1

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IAUC number

                                                  Circular No. 3255
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 617-864-5758

     V. M. Blanco, Cerro Tololo Interainerican Observatory, further
reports that F. Schweizer, M. M. Phillips and J. H. Elias have
analyzed a spectrogram of the supernova in MCG -5-9-22 obtained by
A. C. Danks on Aug. 14.4 UT with the 400-cm telescope plus image-tube
spectrograph and covering the wavelengths 4700-7000 A.  The
supernova is of type II with a featureless spectrum except for
about 8000-km-s**-1-wide (fwhm) H-alpha and H-beta emission lines with P-Cyg
profiles.  The centers of the blue-shifted broad absorption components
show expansion velocities of 7900 km s**-1 with respect to the
galaxy, whose northern spiral arm has a heliocentric radial velocity
of 4060 km s**-1  For a Hubble constant of 50 km s**-1 Mpc**-1, the
galaxy lies at a distance of about 80 Mpc, and the blue absolute
magnitudes uncorrected for absorption are ~ -20.4 and -16.0 for the
galaxy and supernova, respectively.  Because of the scarcity of
suitable published spectra of type II supernovae, the date of the
light maximum cannot be estimated from this single spectrogram.
The current absolute magnitude seems to be somewhat bright for a
six-month-old supernova.  Information from plates of the galaxy
taken since January would be most useful to establish or refute the
proposed identification with the x-ray burst of Feb. 2 (IAUC 3254).

1978 PA
     H.-E. Schuster, European Southern Observatory, communicates
the following additional semiaccurate positions:

     1978 UT             R. A. (1950) Decl.
     Aug. 14.25139     0 08 07      -41 04.6
          15.29028     0 08 30      -41 34.0

1978 P 1
     J. D. Mulholland, University of Texas at Austin, reports that
a 10-min exposure of Pluto was obtained by P. J. Shelus on 1977 May
22.23 UT with the 208-cm reflector at the McDonald Observatory.
The plate scale was ~ 7".5/mm and the seeing 1" or better.  The
image of Pluto was elongated by 10-15 percent in p.a. 180o+ 10o,
in good agreement with the prediction (IAUC 3241).  A nearby star
was elongated by no more than about 1 percent.

1978 August 16                 (3255)              Daniel W. E. Green

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