COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1080


                                Konkoly Observatory
                                Budapest
                                1976 January 8



       OBSERVATIONS OF THE MINIMUM OF Theta' Ori A


   At the Lick Observatory, an attempt was made by the writer to
observe the predicted minimum of Theta' Ori A near 1975 Dec 5.3 or 5.48
(UT) (IBVS 988 and 1025), using the 24-inch reflector and a photometer 
employing a 1P21 photomultiplier. Unfortunately, the night
of Dec 4/5 was overcast, and only two observations of somewhat
uncertain quality were obtained through the clouds. These observations, 
and a single observation through clouds on the following
night, are listed in the accompanying table. These observations
were made in yellow light, through a Corning 3384 filter and using
a focal plane diaphragm 11" in diameter. Theta' Ori D was used as the
comparison star, and the magnitude differences in the table are
given in the sense Theta' Ori A minus Theta' Ori D.


--------------------
Date
1975         DeltaV
 UT            mag
--------------------
Dec 05.442    +1.07
    05.450     1.10
    06.316    +0.04
--------------------


                 M.F. WALKER
                 Lick Observatory
                 University of California
                 Santa Cruz, CA 95064, USA