COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                        Number 3318

                                         Konkoly Observatory
                                         Budapest
                                         11 April 1989

                                         HU ISSN 0374 - 0676


          TWO PHOTOELECTRIC TIMES OF MINIMUM OF 44 i Boo


49 i Boo is a fascinating eclipsing variable due to its dramatically short
period of 0.26781 day. The Yale Bright Star Catalogue suggests that this
system may experience unusual variations in its light curve shape and its
orbital period, perhaps as a result of mass transfer between its two
components.

Photometry of this variable was obtained with the 24-inch Seyfert reflector at
the A. J. Dyer Observatory in Nashville, Tennessee, on the nights of 1988
June 6-7 and 9-10. The detector was a 1P21 photomultiplier tube, cooled with
dry ice and employing pulse-counting electronics. Filters to match the U, B,
and V bandpasses were used on the first night of observation, while just the B
and V filters were used on the second night, increasing the number of
measurements possible. As a comparison star, nearby 47 Boo was used. The
differential magnitudes were corrected for atmospheric extinction and
transformed to the UBV system. Figure 1 shows the B and V light curves
resulting from the second night.

We calculated the times of minimum with a novel approach which made use of the
data at all phases of the light curve. Our differential magnitudes were fitted
with the equation

 l = A_0 + A_1 cos Theta + A_2 cos 2Theta,                        (1)

where Theta is phase computed using a period of 0.26781 day. The above 
equation
was solved successively by least squares with different assumed initial epochs
to find the Julian date which gave the best fit, i.e. the smallest sum of the
squares of the residuals. The results are given in Table 1, and refer to the
primary minimum.

The uncertainties in Table 1 are the formal errors resulting from chi-squared
analysis. They might underestimate the actual uncertainties because our fit
with equation (1) assumes a shape to the entire light curve which is only an
approximation.

Table 1.

Times of primary minimum for 44 i Boo.
Filter            J.D.(hel.)
U          2447319.7446  +-0.0040 d
B          2447319.7495  +-0.0038
V          2447319.7491  +-0.0025
B          2447322.7008  +-0.0012
V          2497322.6999  +-0.0013


                            [FIGURE 1]

 Figure 1. The B and V light curves from the night of June 9-10, 1988.




THOMAS R. WILLMITCH
     and
DOUGLAS S. HALL
Dyer Observatory
Vanderbilt University
Nashville, Tennessee 37235
U.S.A.