COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1507

                                 Konkoly Observatory
                                 Budapest
                                 1978 November 27




       PHOTOELECTRIC MINIMA OF U CrB, u Her AND U Oph


    From 1969 till 1973 photoelectric observations were carried out on
eclipsing binaries in B, V and R with a 40 cm reflector of the Utrecht
Observatory operated during that time at the Astronomical Station at
Stephanion, Peloponnesus, Greece (Heintze, Provoost, 1979).
    We report here O-C values for primary minima of U CrB, u Her and
U Oph. The C values were calculated with ephemeris formulae given by
Kukarkin et al. (1969):

for U CrB with Hel. Min. J.D. = 2416747.964 + 3.45220416. N
for u Her with Hel. Min. J.D. = 2427640.654 + 2.0510272. N and
for U Oph with Hel. Min. J.D. = 2408279.641 + 1.6773460. N

The results are:

--------------------------------------------------------------------------
Star    Hel. Min. J.D.    N         O-C          Number of        Filter
                                   (days)       observations
--------------------------------------------------------------------------
U CrB     2440364.4688   6841    - 0.0239+-0.0011   28             B,V
u Her       41468.6734   6742    - 0.0059+-0.0006   76             B,V,R
U Oph       40724.5330   19343   - 0.0117+-0.0015   16             B,V
--------------------------------------------------------------------------

    Revised ephemeris formulae of U CrB and u Her are given by Van Gent
(1979) and Heintze and Provoost (1979).



                              R.H. VAN GENT
                              J.R.W. HEINTZE
                              P. PROVOOST

                           "Sonnenborgh" Observatory
                           of the Astronomical Inst.
                           at Utrecht, Zonnenburg 2,
                           The Netherlands




References:

Van Gent, R.H.: 1979, Astron. & Astrophys., submitted
Heintze, J.R.W. and Provoost, P.: 1979. Astron.& Astrophys. submitted
Kukarkin, B.V.et al.: 1969, 1970, 1971, Gen.Cat.of Var.Stars 3rd ed.1, 2, 3
                1971, 1974, 1976, 1st, 2nd & 3rd suppl., Publishing
                House "Nauka", Moscow