COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1777

                                Konkoly Observatory
                                Budapest
                                1980 April 30


     PHOTOELECTRIC MINIMA OF SOME ECLIPSING VARIABLES


The eclipsing binaries U CrB, DO Cas and V470 Cyg have been observed - in B and
V - during 1979 with the two-beam, multimode, nebular-stellar photometer of the
National Observatory of Athens attached to the 48-inch Cassegrain reflector at
the Kryonerion Astronomical Station. Thus, one primary minimum has been
observed for U CrB, one primary and one secondary for DO Cas and one secondary
for V470 Cyg.

The following Table summarizes our results. It gives the star's name, the Hel.
Julian Day, the residuals O-C, the mean error sigma and the type of minimum.

Table

Name of the   Hel. J.D.     O-C      sigma     Type of
  star        2444000+     days       days      Min.
V470 Cyg      053.4546    -0.0010    0.0002     II
U CrB         058.3456    -0.0054    0.0003      I
DO Cas        142.3510    -0.0069    0.0006      I
  "           193.3577    -0.0076    0.0009     II

The times of minima as well as the mean errors sigma have been computed by Kwee
and Van Woerden's method (1956). The ephemeris used is that of Kukarkin et al.
(1969).


P. ROVITHIS
National Observatory of Athens,
Athens 306
Greece

H. ROVITHIS-LIVANIOU
Astronomy Dept. Athens University
Panepistimiopolis, Athens 621
Greece

References:

1. Kukarkin, B.V., et al.: 1969, Gen. Cat. of Var. Stars, Moscow [BIBCODE 1969gcvs.book.....K ]
2. Kwee, K.K. and Van Woerden, H.: 1956, Bull. Astr. Inst. Neth. 12, 327 [BIBCODE 1956BAN....12..327K ]