COMMISSION 27 OF THE I. A. U.
      INFORMATION BULLETIN ON VARIABLE STARS
                  Number 1693

                                  Konkoly Observatory
                                  Budapest
                                  1979 October 22





     THE DEVELOPMENT OF THE 1978 OUTBURST OF WZ SAGITTAE



    The December 1978 outburst of the recurrent nova WZ Sge
was followed spectroscopically and photometrically at the Wise Observatory.
However the entire light curve of the present outburst has not been
published. In the Figure we display the curve for the first 4 months
after the eruption. Most of the points have been reported by various
observers in the I.A.U. Circulars and the I.B.V.S. Bulletins. A few
points have been communicated directly to the author, while some represent
measurements obtained with the Wise Observatory 40" reflector.

                            [FIGURE 1]

     The light curve of the present outburst should be compared with
those displayed after the 1913 and the 1946 eruptions (Mayall, 1946).
In the table we compare the main characteristics of the outbursts,
those of the previous events calculated from the plots in Mayall's
paper. The range Delta m was calculated assuming that at minimum the object's
magnitude is 14.5.

Table: Outburst Characteristics of WZ Sge

Year   m_Max Deltam t_3

1913   7.0    7.5   23d
1946   7.7    6.8   21
1978   7.9    6.6   31


    The 1978 gross photometric behaviour of WZ Sge was similar to
that displayed in 1913 and 1946, namely that of a moderately fast nova.
But the present eruption differs in one conspicuous detail from the
previous ones. Near Jan 1.0, 1979 a sudden light drop of about 2
magnitudes occurred for about one day. This drop was followed by a
one day recovery with a subsequent, shallower drop, also of about one
day duration. In the next few days the magnitude variations of the
object-were apparently more pronounced than during the first month of
the outburst. The subsequent development of the nova was characterized
by a slow return to the quiet state.
    Thus Jan. 1, 1979, the onset of the oscillatory behaviour, is
revealed to be another important date in the recent history of WZ Sge,
along with Dec. 1, 1978, the date of the outburst (Patterson, 1978),
and Dec. 9 or 10, 1978, when the photometric period apparently increased
by 0.8 min. (Targan, 1979; Bohusz and Udalski, 1979).


                       NOAH BROSCH
                       Dept. of Physics and Astronomy
                       and the Wise Observatory
                       Tel Aviv University
                       Tel Aviv, Israel.

References:
Bohusz, E., Udalski, A., 1979, I.B.V.S., No. 1583
Mayall, M.W., 1946, Harvard Bull. 918, 3 [BIBCODE 1946BHarO.918....3M ]
Patterson, J., 1978, I.A.U. Circular No. 3311 [BIBCODE 1978IAUC.3311....1P ]
Targan, D., 1979, I.B.V.S., No. 1539