COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                   Number 2880

                                 Konkoly Observatory
                                 Budapest
                                 17 March 1986

                                 HU ISSN 0374 - 0676



THE HISTORICAL OPTICAL VARIATION OF DO Dra (=3A1148+719)


   A search of the Harvard College Observatory plate
collection for outbursts of this CV encompassed the following 
numbers of plates and epochs (all magnitudes are blue):

1) very-wide-angle patrol series: 223 plates with limiting
  magnitudes of 13.7 mag or fainter, and more than 200
  additional plates of limit 12.2 mag or fainter, 1899-
  1951;
2) wide-angle patrol series: 118 plates with limit 13.7
  mag or fainter, 1928-1951;
3) recent very-wide-angle patrol series: 91 plates with
  limit 13.7 mag or fainter, 1968-1984;
4) other, non-patrol series: 100 plates with limit 13.7
  mag or fainter, 1890-1944.
   Only three outbursts were detected, with data given
in the table below. At other times the variable, when

        Table: Outbursts of the CV DO Dra


       Julian Date   Mag
     (2,400,000+)    (B)
         28262.7   >12.2 invisible
         28266.7    10.8:
         28267.7    11.1
         28273.7   >12.2 invisible

         31498.7   >14.5 invisible
         31499.7   >12.2 invisible
         31504.7    10.0:
         31505.8    10.8:
         31506.7    11.2
         31511.6   >12.2 invisible
         31519.9   >13.7 invisible

         33242.9    11.2
         33279.8   >14.4 invisible

seen on the plates, had magnitudes between 16 and 17, with
occasional points brighter than 16 mag.
   Clearly, from the table, the outbursts are of short
duration, lasting no more than ten days and probably even
less. Thus, many outbursts would be quite easy to miss
entirely. However, the number of outbursts observed,
coupled with the number of plates searched, suggests that
outbursts of this object are relatively infrequent.



                      MARTHA L. HAZEN

                      Harvard-Smithsonian Center
                      for Astrophysics
                      60 Garden Street
                      Cambridge, MA 02138
                      U.S.A.