COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1027

                             Konkoly Observatory
                             Budapest
                             1975 August 4


         PHOTOELECTRIC OBSERVATIONS OF UV Cas


    The variability of UV Cas (26.1913) was first detected by
D'Esterre (1913) who gave photographic magnitudes of 12.3m at maximum 
and 16.5m at minimum light of the star. According to these 
observations Ludendorf (1919) included UV Cas in a list of R CrB stars.
Gitz (1935) using plates taken from 1896 to 1907 and from 1933 to
the beginning of 1935 obtained a 13.4m (mpg) minimum and a nearly
constant 11.8m maximum. Payne-Gaposchkin and Gaposchkin (1938) 
questioned Lunderdorf's classification and placed the star in the 
doubtful R CrB stars list. Floria (1946) quoted the maximum from Gitz
and the minimum from D'Esterre. Petit's (1960) visual observations
(32 points during 706 days) show a constant brightness of 10.8m.
Weber (1966) observed UV Cas from 1945 to 1959 and from 1969 to 1965;
his results show a steady light curve at about 11.7 mpg with a maximum 
of 11.4m (in 1964, one night) and a minimum of 12.0m (in 1956 one
night; in 1958 two successive nights). Isles (1973) communicated
three visual estimates of 10.9, 11.2, 11.5 mv.
     The plot in Figure 1 shows all observations mentioned above.

                      [FIGURE 1]

                      [FIGURE 2]

-------------------------------------------------
J.D.     Deltam J.D.      Deltam J.D.      Deltam
2442000+        2442000+         2442000+
-------------------------------------------------
006       .13   087        .14   281        .05
022       .22   097        .04   331        .10
023       .21   157        .90   338        .12
028       .14   217        .35   349        .08
030       .12   219        .30   395        .09
064       .06   238        .19   386        .08
070       .09   243        .06   399       -.02
                                 417        .10
-------------------------------------------------


     Photoelectric observations in V light, from November 1973
to January 1975, carried out using the 90 cm refractor of the Teramo
Observatory are given in Figure 2 and in the Table; a 0.4 magn. deep
minimum occurred in April 19, 1974.
     Finding chart (from Weber) with comparison (a) and check
(b) stars is given in Figure 3.
                      Some doubts about the classification of UV Cas
                      as R CrB star arise analyzing the data; during
                      69 years of observations only one deep minimum
   [FIGURE 3]
                      (based on 4 nights in 1913) is known.
                      Spectroscopic observations are necessary to
                      classify this star properly.



                          F. ZAVATTI
                        Teramo Astronomical
                      Observatory, I-69100 Teramo



References:

D'Esterre C.R., 1913, AN 9697, 301 [BIBCODE 1913AN....196..301D ]
Floria H.F., 1946, VS, 6, 3
Gitz H., 1935, VS, 5, 21
Isles J.E. IAU Circ 2597, 1973
Ludendorf H., 1919, AN, 5010 281  [BIBCODE 1919AN....209..273L ]
Payne-Gaposchkin and Gaposchkin, 1938, Variable Stars
Petit M., 1960, Journal des Obstrvateurs, 43, 79 [BIBCODE 1960JO.....43...79P ]
Weber R., 1966, Bull.Stat.Astr.Mainterne, 9