COMMISSION 27 OF THE I. A. U.
     INFORMATION BULLETIN ON VARIABLE STARS 
                 Number 1685

                                  Konkoly Observatory
                                  Budapest
                                  1979 October 15



       EPOCHS OF MINIMUM LIGHT, SW LACERTAE

   SW Lacertae (BD+37d4717) is a W Ursae Majoris-type eclipsing
binary system which undergoes partial eclipses. Jameson and
Akinci (M.N.R.A.S. 188, 421, 1979) observed the light curve of
this system at 1.2 and 2.2 micro m. They kindly provided the present
authors with the unpublished data.

   Epochs of minimum light were determined from the observations
defining one primary and one secondary eclipse curve. The 
bisection-of-chords technique was utilized since there is noticeable
asymmetry in the primary eclipse curve. Table I includes the
epochs of minimum light and the O-Cs calculated from the ephemeris
given by Bookmyer (Astron. J. 70, 415, 1965), namely

     JD Hel. Min. I = 2437572.57231+0.32072811d E.

                        TABLE I

        JD Hel.                 Min.         O-C
      2443411.4804              II        -0.1075
      2443411.6343              I         -0.1140

The residuals are consistent with the O-C plot published by
Faulkner and Bookmyer (IBVS #1503, 1978).

   It should be noted that _all_ the available epochs of minimum
light for SW Lac - visual, photographic, and photoelectric -
have been collected and tabulated by Bookmyer and Faulkner. Upon
request, these will be sent to any investigator interested in
them for future studies.


                    DANNY R. FAULKNER
                    P. A. BASILICO
                    BEVERLY B. BOOKMYER
                    Dept. of Physics and Astronomy
                    Clemson University
                    Clemson, SC 29631 USA