COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 515

                               Konkoly Observatory
                               Budapest
                               1971 February 8


A POSSIBLE FIFTH SUPERNOVA (1969) IN THE SPIRAL GALAXY
               	   NGC 6946

A new stellar object (Fig. 1) of magnitude 13.9 pg
has been observed by the writer 180" South and 5" West of
the nucleus of the spiral galaxy NGC 6946 (RA 20h33.9m;
D.+59d58';1950.0) on two photographs taken with the
40-50-100 cm Schmidt telescope of Asiago on Dec. 11, 1969 at
DT 18h28m (Panchro Royal, 15m) and 18h46m (103a-O, 10m). The
object was discovered by comparing these plates with a 
recent pair of photographs, obtained with the same instrument
and emulsions, on Dec. 20, 1970.
The object was not visible on Dec 1, 1969, neither
it was seen in earlier photographs or reproductions of
NGC 6946. Schmidt films of Oct 24 and Dec 20, 1970 don't
show any trace of it.
In principle, the possibility that the object may
be a slowly moving asteroid cannot be ruled out, although
its high declination and the absence of elongation or 
sensible motion on the photographs taken during the night of
Dec 11, 1969 weaken this hypothesis. Moreover the star is
well inside the galaxy NGC 6946, who is famous for having
shown a high rate of appearance of supernovae. The four
previously known are:

1917 A    37" W    105"S     14.6 pg
1939 C    215 W     24 N     13.0
1948 B    222 E     60 N     14.9
1968 D     45 E     20 N     13.5

The pg magnitude (13.9) of the new object does not disagree
therefore with the magnitudes of the other supernovae found
in this galaxy. Unfortunately, in the series of Asiago
plates centered in NGC 6946 there is a gap of ten months
from Dec 11, 1969 to Oct 24, 1970, during which no photographs 
were taken. Observations made during this period,
and particularly on December-January 1969-70 would be of the
utmost importance to decide whether a fifth supernova has
appeared in this spiral galaxy or whether it was simply a
passing asteroid or a field variable star.


                   [FIGURE 1]

      Fig. 1 reproduces the identification chart of the 
object with the approximate positions of the other four 
supernovae. The new object is situated Within the galaxy, over a
faint extension of a spiral arm.



                            L. ROSINO

                 Astrophysical Observatory of Asiago