COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                    Number 2262

                                     Konkoly Observatory
                                     Budapest
                                     1983 January 10

                                     HU ISSN 0374-0676



   THE X-RAY SOURCE 3A1148+719 IS ANOTHER DWARF NOVA WITH VERY LONG
                      CYCLE LENGTH




The X-ray source 3A1148+719 (= 2A1150+720) has been identified by Green
et al. (Publ. Astron. Soc. Pac. 94, 560) and by Patterson et al. (Bull. Amer.
Astron. Soc. 14, 618) with a 15th to 16th magnitude star showing U Geminorum-
like spectra. An identification of the object with the 12th magnitude Algol
variable YY Draconis discovered by Tsesevich (Perem. Zvezdy 4, 291) has also
been suggested because of the apparently near coincidence of the published
positions.
After having inspected a sample of 950 Sonneberg sky patrol plates centred
at 12h +80deg which were taken by H. Huth during 700 nights of the years 1963
to April 1982 I came to the following conclusions:
1. A 12th magnitude star near the given position of YY Dra (which is  3.1
minutes of arc south of BD +72deg544) is constant; no Algol variable with the
properties published by Tsesevich)(l.c.: P = 4.21123d, range 12.9mag...>14.5 pg)
can be found. Probably the catalogued position is erroneous. In this way the
fact that since Tsesevich's note in 1934 to my knowledge further observations
of the genuine YY Dra have not been reported can also be explained.
2. At a place approximately 4.0 minutes of arc to the south of BD +72deg544
(and slightly following) I have found an interesting eruptive object, which
could be localized easily on the Palomar prints. The plate series mentioned
above shows it bright (10.6mag pg) in two nights only (UT 1968 Nov. 10.8 and
1975 Nov. 23.8) and otherwise invisible fainter than the plate limit, which
is about 14.5mag on numerous exposures and in most cases not poorer than 13.5mag.
These two eruptions are confirmed without doubts on plates of the adjacent
(overlapping) field and on photovisual plates taken simultaneously. With
certainty this object is the cataclysmic star classified spectroscopically
and by the presence of X-ray radiation. Concerning the mean cycle length,



which should be for statistical reasons of the order of 5...20 years, the
object obviously is very much alike BZ UMa (see IBVS No. 2256).
3. YY Dra is not identical with 3A1148+719; anyhow, the brightness published
for the "normal" levels of the two stars contradict each other.





           W. WENZEL
           Sternwarte Sonneberg
           Zentralinstitut fur Astrophysik
           der Akademie der Wissenschaften
           der DDR