COMMISSION 27 OF THE I. A. U.
              INFORMATION BULLETIN ON VARIABLE STARS
                            NUMBER 57

                                           Konkoly Observatory
                                           Budapest
                                           24 June 1964


                            i BOOTIS


      From 21 photoelectric observations obtained between J.D.
243 8540.3991 and  .5087 the following epoch of minimum can be
derived:
         Hel. J.D. 243 8540.4649 +- 0d.0003 m. e.
The elements
         Min = J.D. 243 7362.6179 +- 0d.267 814 191.n
                          +-    2            +- 171 m.e.
valid after March 1961 provide O - C = + 0d.0002.
      The mean error of the 15 minima observed since March 1961
and used in deriving the above ephemeris amounts to + 0d.00055.
      Before March 1961 the following elements were valid:
Min = J.D. 243 4132.517 + 0d.267 812 271. n + 0d.115242.10^-9. n^2.
               +-   0005          +- 220      +- 017....10^-9 m. e.

     This formula is based on 41 minima and gives for the mean
error of one minimum + 0d.0012.
     The period of i Bootis seems to be practically constant since
March 1961.

     A more exhaustive discussion will follow elsewhere.

Potsdam, 11 June 1964
                                       H. SCHNELLER
                                 Astrophysical Observatory