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

                  Number 445

                             Konkoly Observatory
                             Budapest
                             197U July 8

           TIME OF MINIMUM FOR WY HYDRAE

The eclipsing binary WY Hya was observed photoelectrically
on the UBV system on one night in March, 1970 at the
No. 1 1.6-inch telescope of the Cerro Tololo Inter-American
Observatory. The are just enough observations to roughly
determine a time of secondary minimum. Solovyev's /1958/
star "a" was used for, the primary comparison star.

Column 1 in Table A lists the heliocentric Julian date.
Columns 2, 3 and 4 list the differential V, /B-V/ and /U-B/
magnitude and color indices in the sense variable minus
comparison.


                                Table A

      HJD             Delta V       Delta /B-V/     Delta /U-B/

 2440676.5689          +1.262          +0.336           -0.126      
        .5713           1.317            .326           -0.112 
        .5758           1.409            .292           -0.082
        .5780           1.399            .338           -0.102
        .5849           1.526            .329           -0.048
        .5868           1.532            .331           -0.143
        .6006           1.396            .308           -0.130
        .6030           1.284            .368           -0.112
        .6080          +1.205          +0.334           -0.078

The derived heliocentric Julian Day time of secondary minimum 
is HJD 2440676.587 +-0.0001. Based upon the ephemeris
quoted by Koch, Sobieski and Wood /1963/, the O-C for this
secondary minimum is -0.d029

This work was supported by the National Science Foundation.


References

Koch, R.H., Sobieski, S., and Wood, F.B. 1963,Publ. of Univ.
     of Pennsylvania, Astronomical Series, Vol.9.

Solovyev, A.V. 1958, Peremennye Zvezdy, 12, 626.




                ARLO U. LANDOLT
                Louisiana State University Observatory
                Balton Rouge, Lousiana