COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                   Number 1812

                                        Konkoly Observatory
                                        Budapest
                                        1980 July 3






 NEW BV LIGHT CURVES AND MINIMA OF THE ECLIPSING BINARIES:

              W UMa, AW UMa AND 44i Boo





We made 1318 photoelectric observations in B and V light of
three W UMa type systems between February and May 1980. A
photometer equipped with an unrefrigerated RCA 1P21 photomultiplier 
tube and standard Johnson B, V filters have been used, attached 
to the 20 cm Zeiss refractor of the Torun Observatory in
Piwnice. In the observations following stars were used as comparison 
stars: BD +56deg1397 for W UMa, BD +31deg2270 for AW UMa and
BD +48deg2261 for 44i Boo, respectively. From these data times of
minima have been calculated by using the Kwee and van Woerden
(1956) method.
  The Table gives the heliocentric minima with their standard
errors (sigma), filters, the interval of the period (Delta P) used for
calculating the minima and corresponding (O-C)'s. (O-C) values
for W UMa were calculated from the ephemeris given by Cester
and Pucillo (1973); for AW UMa from Dworak and Kurpinska (1975);
for 44i Boo from Pohl (1967). AW UMa has been observed only in
V light.
                          Times of minima
Star    Min.       JD Hel.   sigma    Filter   Delta P      (O-C)
                 2444000+    x10^-5
W UMa   II     291.56544      11        BV       0d065     +0.0020
        I      302.40708      23        BV       0.050     +0.0004
        II     302.57509      11        BV       0.060     +0.0016
        I      303.40786      10        V        0.070     +0.0002
        II     303.57460      24        V        0.030     +0.0002
        I      313.41757       1        BV       0.070     +0.0008
AW UMa  I      320.39578      58        V        0.130     -0.0130
        II     343.43098      64        V        0.100     -0.0112
44i Boo II     345.50670      12        BV       0.030     +0.0320
        I      365.45694      33        BV       0.058     +0.0300
        I      366.52904      16        BV       0.060     +0.0309


                    [FIGURE 1]
                    [FIGURE 2]
                    [FIGURE 3]



    The observations have been reduced in phase by using:
Hel. JD Min. I = 2444302.40692 + 0.3336559 .E, for W UMa,
Hel. JD Min. I = 2444320.39578 + 0.43873234  E, for AW UMa,
Hel. JD Min. I = 2444366.52904 + 0.2678158  E, for 44i Boo.


The obtained light curves are shown in Figs. 1-3.








                      JOANNA MIKOLAJEWSKA
                      MACIEJ MIKOLAJEWSKI
                      Institute of Astronomy
                      Nicolaus Copernicus University
                      Chopina 12/18
                      87-100 Torun, Poland




References:
Cester, B., Pucillo, M., 1973, Mem.S.A.It., 44, 201 [BIBCODE 1973MmSAI..44..201C ]
Dworak, T.Z., Kurpinska, M., 1975, Acta Astron., 25, 417 [BIBCODE 1975AcA....25..417D ]
Kwee, K.K., van Woerden, H., 1956, B.A.N., 12, 327 [BIBCODE 1956BAN....12..327K ]
Pohl, E., 1967, I.B.V.S. No. 209