COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1365

                                  Konkoly Observatory
                                  Budapest
                                  1977 November 25




        OBSERVATIONS OF THE STAR GAMMA BOOTIS
        AND OF THE NEW VARIABLE STAR HR 5441




   The star Gamma Bootis (HR 5435, A7 III, m_v= 3.03) is a known
intermittent variable. When the light variations of this star can
be detected its period is about 0.29 day and the amplitude seems
to vary between the detection limit and 0.1 magnitude in B. A 
detailed bibliography on this star may be found in Sareyan et al.
(1971).
   The classification of Gamma Bootis is not yet clear. Baglin
et al. (1973) classified it as "peculiar" in their review paper
on Delta Scuti stars. This star falls on the blue edge of the
instability strip. Its location in the H.R. diagram indicates
that Gamma Bootis may be a Delta Scuti star.
   We observed it in May 1977 at the new one meter telescope
in the Chiran station (1900 meters height above sea level) of
the Haute-Provence Observatory. The photoelectric photometer of
the station was equipped with an unrefrigerated EMI 5256 
photomultiplier. The data were obtained on an analogic recorder. We
used only one narrow band filter centered at lambda4670, Delta lambda=100 Angstroms
described in Le Contel et al., (1974). Two comparison stars have
been used; C_1, HR 5441 (F5, m_v=6.4) and C_2, HR 5373 (A2 V,m_v=6.3).
As the studied variable is three magnitudes brighter than the two
comparison stars, a neutral density filter (D=1.2) was used in
order to avoid fatigue effects of the photomultiplier. Our 
observational sequence was: C_1, sky, variable, C_2 .... The treatment 
of the data was made in the usual way. The differences in
magnitude, Gamma Bootis minus HR 5373, Gamma Bootis minus HR 5441
and HR 5373 minus HR 5441 are plotted in Figure 1. From this
figure it appears that:
1) There is no variation in the light of Gamma Bootis during the
three hours we have been observing it. Any variations with an
amplitude greater than 0.01 magnitude should be detected. This
result confirms the intermittence in the pulsation of Gamma
Bootis. (Jerzykiewicz, 1968; Sareyan et al., 1971).
2) The star HR 5441 is clearly variable with an amplitude of at
least 0.02 magnitude and a period longer than three hours, From
its spectral type F5 this star is a probable Delta Scuti type
variable. So we may derive (Baglin et al., 1973) that if the star
is in the instability strip, it must be a giant which is consistent 
with a value of the period between two and four hours.





    AUVERGNE M., LE CONTEL J.M., SAREYAN J.P., VALTIER J.C.

        Groupe Etoiles variables a courtes periodes
        Observatoire de Nice, B.P. 252,06007 Nice Cedex              
                    France


                  DAGUILLON J.
             Observatoire de Haute-Provence
             04300 Forcalquier, France


References:
Baglin, A., Breger, M., Chevalier, C., Hauck, B., Le Contel, J.M.,
     Sareyan, J.P., Valtier, J.C., 1973, Astron. and Astrophys.
     23, 221 [BIBCODE 1973A&A....23..221B ]
Jerzykiewicz, M., 1968, Inf.Bull.Var. Stars No. 319
Le Contel, J.M., Valtier, J.C., Sareyan, J.P., Baglin, A.,
     Zribi, G., 1974, Astron. and Astrophys. Suppl. 15, 115 [BIBCODE 1974A&AS...15..115L ]
Sareyan, J.P., Zribi, G., Bijaoui, A., 1971, 
     Inf. Bull. Var. Stars No. 531


                             [FIGURE 1]