COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 3432

	                              Konkoly Observatory
        	                      Budapest
                	              8 February 1990

                        	      HU ISSN 0374 - 0676


     LONG-TERM LIGHT-CURVE OF THE IRREGULAR VARIABLE OR ANDROMEDAE

   The variability of OR And (206.1940 = NSV 14419) was announced by
Hoffmeister (1940), who described the star provisionally as "slowly 
varying, probably irregular, with long standstills". Huth (1956) discovered
non-periodic short-term fluctuations of small amplitude (0.6 mag) and a
time scale of hours: in the time interval covered by 224 plates available
to him (242 7955...243 3977) the star did not exhibit large long-term 
variations (see also the upper part of Figure 1).
   Downes (1986), without knowing these findings, independently detected
the outstanding nature of the object in the course of a spectroscopic survey 
for potential novae. He found narrow H-alpha, beta, gamma and He II 4686 emission
lines and a fairly flat Balmer decrement which is typical of cataclysmic
variables: for the Harvard plate collection the star proved to be too faint
to be investigated properly.
   Kurochkin (1987) observed the variable on 83 Moscow 40cm astrograph
plates and found three conspicuous minima and also short-term variations of
several time-scales: unfortunately, however, the exposures are rather 
irregularly spaced.
   In the course of a routine investigation of variables in the Sonneberg
field 23h09m +52.5d (Haussler 1990) OR And again attracted attention. With
the help of nearly 450 plates a fairly dense long-term light-curve from
242 7955 to 244 7770 (gaps are from 243 4200 to 5700 and from 244 2400 to
5600) could be constructed and thus the photometric pattern, described by
the above authors, greatly improved. The light-curve resembles that of MV
Lyr prior to its great minimum (Wenzel and Fuhrmann 1983) or of V 425 Cas
(Wenzel 1987): the star was bright with minor changes from 1935 to 1952. It
was very active from 1956 to 1974 with alternating bright and low states:
the latter lasted several years in general and were as deep as some magnitudes 
below "normal" light. A much narrower minimum (duration 50 days) happened 
in the autumn of 1985 (Kurochkin 1987), with a subsequent high state
till summer 1989. The comparison stars were linked to Mt. Wilson Selected
Area 42.


                           [FIGURE 1]


   Figure 1 shows two representative parts of the light-curve. Observations 
of Kurochkin are included (open circles). Larger signs denote average 
brightness data composed from up to 10 individual values. The four
signs in brackets are derived from Kurochkin's data, whose magnitudes in
the lower part seem to be too faint by about 1 mag.
   We conclude that our light-curve supports the supposition first 
expressed by Downes that the star is a cataclysmic variable. Spectroscopic
and photoelectric observations are strongly recommended.



         W. WENZEL                            K. HAUSSLER

      Sternwarte Sonneberg           Bruno- H.- Bürgel- Sternwarte
   Zentralinstitut für Astrophysik            DDR - 7302 Hartha
   Akademie der Wissenschaften der
             DDR
      DDR - 6400 Sonneberg

References:

Downes, R.A.: 1986, Astrophys.J. 307, 170. [BIBCODE 1986ApJ...307..170D ]
Haussler, K.: 1990, Veroff. Sternwarte Sonneberg 10, Nr. 4
        (in preparation).
Hoffmeister, C.: 1940, Astron. Nachr.- Astron. Abh. 10, Nr. 2.
Huth, H.: 1956, Veroff. Sternwarte Sonneberg 4, 146.
Kurochkin, N.E.: 1987, Astron. Tsirk. 1482, 1. [BIBCODE 1987ATsir1482....1K ]
Wenzel, W.: 1987, Inf. Bull. Variable Stars No. 3086
Wenzel, W., Fuhrmann, B.: 1983, Mitt. Veranderl. Sterne 9, 175. [BIBCODE 1983MitVS...9..175W ]