COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1502

                                 Konkoly Observatory
                                 Budapest
                                 1978 November 9





           MINIMA OF ECLIPSING BINARY STARS


    Presented are 33 minima of eclipsing binary stars. All
observations were visual with both the descending and ascending
branch of the light curve observed. Times of minima were found
by the tracing paper method.
    Column one gives the heliocentric time of minima. Column
two gives the number of visual brightness estimates used in the
light curve. Columns three and four give the epoch and O-C from
the linear elements of GCVS 1969. Epoch and O-C for AZ Virginis
are from the linear elements of studies by Meinunger, L. (March
1977, Mitteilungen uber Veranderliche Sterne, 185-188). Column 5
gives the standard deviation, sigma expected for a single visual
minimum of that star is given. These standard deviations are
calculated from studies by Mallama, A.D. (1974a, JAAVSO, 3, 11
and 1974b, JAAVSO, 3, 49).

Telescopes used were as following: 20.3 cm refractor,
36.2 cm reflector, and a 15.2 cm reflector.


JD hel.              n   Epoch    O-C days   sigma
2,440,000+
--------------------------------------------------
OO Aquilae
3348.654            10   18594   -.043       d.009
WW Aurigae
3127.690             9   4032.5  +.011       .004
SV Camelopardalis
3219.717            11   15921   -.004       .004
3225.643             8   15931   -.009
3231.572             7   15941   -.011
3244.616             9   15963   -.014
3263.600            10   15995   -.009
3381.637             9   16194   +.007
3591.579             7   16548   +.002
RZ Cassiopeiae
3428.586             8   5258    -.011       .003
U Coronae Borealis
3274.683          10   7684     -.018       d.004
3350.623           8   7706     -.027
Y Cygni
3340.627           8   11282.5   +.177      d.016
3352.615           8   11286.5   +.180
ZZ Cygni
3298.687          10   35254     -.036       .006
V477 Cygni
3339.650          12   4471      -.021       .007
AI Draconis
3273.643          10   3517      +.003       .002
3291.625           9   3532      +.003
3701.615           9   3874      -.001:
YY Eridani
3461.727           9   30620     -.007       .002
CT Herculis
3260.717           8   2186      +.058       .018
SZ Herculis
3274.709          10   10130     +.033       .002
3283.706          11   10141     +.030
FL Lyrae
3248.703           8   2308     -.028        .013
RU Monocerotis
3225.587          11   3789.5    +.030      .006
ER Orionis
3211.616          10   15831    -.029       .007
3479.647           8   16464    -.011
V505 Sagittarii
3368.627           9   8330     -.022       .05
HU Tauri
3185.625           9   8532      +.014      .009
X Trianguli
3427.616           9   6027     -.044       .006
3428.588           8   6028     -.044
AZ Virginis
3587.704          10   44789    -.011       .003
3600.648          10   44826    -.005
-------------------------------------------------

JD hel. equals the heliocentric Julian Day for minima. n equals
the number of visual brightness estimates used to plot the light
curve. Epoch and O-C   are from the linear elements in the 1969
General Catalogue of Variable Stars.(See introductory note  on
AZ Virginis).


                          CHRISTOPHER P. STEPHAN
                          Mahoning Valley Observatory
                          Braceville, Ohio 44444, U.S.A.