COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 172


                                    Konkoly Observatory
                                    Budapest
                                    29 December 1966




             NEW MICROVARIABLE HD 117555

        According to P.W. Merrill (1) the star HD 117555 has rather
  large rotational velocity (v sin i = 75 km/sec), the spectral class
  being gG. Halpha and CaII H and K are in emission. It was found also
  that the profiles of emission lines vary with a period of about
  5 days (2).
        We have obtained photoelectric observations of HD 117555.
  The star was observed during May-August 1966. The photometer
  equipped with blue and yellow filters on the 64-cm telescope was used.
  The comparison stars were HD 117567 and HD 117876.
        We conclude that the light of HD 117555 varies periodically,
  the elements of variation being:


           Min. hel. = 2439298. 818 + 2.412d E.

                       [FIGURE 1]

        The light curves obtained are given in the figure where Delta m_y
  and Delta m_b are magnitude differences in the yellow and blue light with
  respect to HD 117567.
        The type of variability as well as the properties of the star
  (high rotation and late spectral class) are unusual.


                                         P. F. CHUGAINOV
                                  Crimean Astrophysical Observatory
                                  of the Academy of Sciences of the
                                              U. S. S. R.





  (1) P. W. Merrill, 1948, Publ. Astron. Soc. of the Pacific, 60, 382. [BIBCODE 1948PASP...60..382M ]
  (2) G. H. Herbig, 1965, Private Communication.