COMMISSION 27 OF THE I. A. U.
       INFORMATION BULLETIN ON VARIABLE STARS
                    NUMBER 344

                              Konkoly Observatory
                              Budapest
                              1969 April 16

           UBV PHOTOMETRY OF AK VIRGINIS

      The eclipsing binary AK Vir was observed 
photoelectrically on 3 nights in June 1968 with the Dyer 
Observatory 24-inch reflector. The results are presented here
now because the observations are not sufficient for a light
curve solution and no further observations are planned.
       Column 1 lists the heliocentric Julian date. Columns
2, 3 and 4 list the differential V, B, and U magnitudes in
the sense AK Vir minus comparison. The comparison star used
was HD 123037, which is the visually brighter component of
BD -17deg4002.


                             Table A


24400..  DeltaV    DeltaB  DeltaU  24400..   DeltaV  DeltaB  DeltaU
23.6452   -        -       1.997   25.6991   3.540   -       -
  .6460   -        1.862   -         .7004   -       3.436   -
  .6468   2.095    -       -         .7017   -       -       3.557
  .6478   2.093    -       -         .7024   -       -       3.675
  .6490   -        1.832   -         .7036   -       3.417   -
  .6502   -        -       1.945     .7050   3.496   -       -
  .6566   2.058    -       -         .7099   3.383   -       -
  .6581   -        1.727   -         .7108   -       3.213   -
  .6593   -        -       1.803     .7120   -       -       3.365
  .6601   -        -       1.821     .7130   -       -       3.423
  .6614   -        1.754   -         .7145   -       3.180   -
  .6625   2.084    -       -         .7158   3.291   -       -
25.6057   2.154    -       -         .7204   3.211   -       -
  .6070   -        1.868   -         .7217   -       3.043   -
  .6083   -        -       1.979     .7232   -       -       3.129
  .6092   -        -       1.991     .7238   -       -       3.123
  .6104   -        1.892   -         .7254   -       2.944   -
  .6114   2.198    -       -         .7265   2.936   -       -
  .6737   3.266    -       -       26.5870   2.065   -       -
  .6748   3.299    -       -         .5880   -       1.798   -
  .6795   3.408    -       -         .5892   -       -       1.931
  .6809   -        3.290   -         .5898   -       -       1.921
  .6822   -        -       3.455     .5906   -       -       1.922
  .6829   -        -       3.439     .5918   -       1.746   -
  .6840   -        3.374   -         .5926   2.049   -       -
  .6850   3.483    -       -         .6006   2.032   -       -
  .6891   3.506    -       -         .6018   -       1.746   -
  .6902   -        3.441   -         .6032   -       -       1.840
  .6914   -        -       3.635     .6042   -       -       1.868
  .6921   -        -       3.579     .6062   -       1.789   -
  .6932   -        3.445   -         .6080   2.066   -       -
  .6947   3.582    -       -         .6090   2.062   -       -


      The time of primary minimum was JD (hel.)
2,440,025.695d +/- 0.001d. The old ephemeris, 2,427,551.395 +
1.193595d, gives an O-C of +0.036d and thus appears inadequate.
The following new ephemeris, 2,440,025.6946 +/- 1.19359875
gives satisfactorily small O-C's for all known times of
minimum. The last digit in each constant is probably 
significant.


                    Table B

Piotrowski (Acta Astronomica 2,70)   +0.0009d /-+ ?
Tsesevich (Odessa Izvestia, 4,
part 3, 66)                          -0.0004d +/- 0.001
Soloviev (Variable Stars 12, 276)    -0.0008d +/-  ?
Hall (this paper)                    +0.0004d +/- 0.001


      From the observations it can be seen that primary
minimum is partial, 1.49m deep in V, 0.17m redder in B-V,
and 0.06m redder in U-B.

      I am very grateful to Mr. Samuel L. Weedman for help
with much of the data reduction.




                         DOUGLAS S. HALL

                         Dyer Observatory
                       Nashville, Tennessee