COMMISSION 27 OF THE I.A.U.
                 INFORMATION BULLETIN ON VARIABLE STARS
                             Number 3206

                                                         Konkoly Observatory
                                                         Budapest
                                                         22 June 1988

                                                         HU ISSN 0374 - 0676


                   A PERIOD CHANGE IN WY CANCRI

Chambliss (1965, 1975) presented epochs of minimum light for WY Cancri
and combined these with previously published times of minimum light to get a
period of 0.8293712, with a probable error of 1 in the last place. Chambliss
noted the constancy of the period, while Ahnert (1973) noted that the period
had remained constant for 40 years. Faulkner (1986) presented two epochs of
minimum light which had small negative (O-C)'s using Chambliss's light
elements. This suggests that a small period change may have occurred, though
Faulkner did not comment on this.  We present two new times of minimum light
and a new set of light elements that indicate that the period has changed.
   An Optec photometer was used on the 41cm David Irons telescope of the
Charlotte Amateur Astronomy Club. Differential B and V measurements were made
using BD+27d1701 as the comparison and BD+28d1672 as the check star. Because
the size of the detector exceeded 40", no attempt was made to exclude the
light of a faint companion 20" from WY Cancri (Chambliss, 1975). Because of
the color of WY Cancri, the B curves had much more scatter than the V curves,
so only the V curves were used to find epochs of minimum light. The Hertzsprung
method was used for this, and the epochs are given as:

             Hel. J.D.        E          (O-C)

           2447202.7774     25,140      -0.0049
           2447241.7580     25,187      -0.0047

where the residuals were computed using the light elements of Chambliss (1975)
   Because these residuals are about 7 minutes, a new set of light elements
was obtained by combining these two epochs of minimum light with those of

Faulkner:

          H.J.D. MIN.I = 2446025.9017 + 0.82936984d E.
                                 +/-2        +/-18

   Note that this period is 0.12 sec. shorter than that of Chambliss, while the
probable error in the period is about ten times smaller than this difference.
The epochs of minimum light used to get the above light elements, as well as
the residuals, are given below.

         Hel. J.D.         E       (O-C)

        2446025.9014       0      -0.0003
        2446143.6726       142    +0.0004
        2447202.7774     1,419    -0.0001
        2447241.7580     1,466    +0.0001



    CHRISTOPHER R. MULLIS              DANNY R. FAULKNER

   501 Highland Forest Drive       University of South Carolina-
      Charlotte, NC 28226                  Lancaster
            U.S.A.                    Lancaster, SC 29720
                                            U.S.A.



References:

Ahnert, P., 1973, MVS Sonneberg, 6, 107
Chambliss, C.R., 1965, A.J., 70, 741. [BIBCODE 1965AJ.....70..741C ]
Chambliss, C.R., 1975, Inf. Bull. Var. Stars, No. 1029.
Faulkner, D.R., 1986, P.A.S.P., 98, 605. [BIBCODE 1986PASP...98..605F ]