COMMISSION 27 OF THE I. A. U.
                  INFORMATION BULLETIN ON VARIABLE STARS
                               Number 2465



                                                       Konkoly Observatory
                                                       Budapest
                                                       27 January 1984

                                                       HU ISSN 0374-0676



                      NARROW BAND PHOTOMETRY OF FG Vir

  FG Vir = HD 106384 was discovered as a variable star by Eggen (1971) who
classified it as a delta Scuti star from the general behaviour of the light curve
taken during the night of March 11, 1970.
  In order to confirm the delta Scuti character of the light variation of FG Vir,
we have carried out multicolor photometry during three nights in March, 1982.
  The equipment utilized consisted essentially of a 60 cm telescope with an
analogic photometer and a set of narrow band filters designed specifically
for delta Scuti variables and described in Le Contel et al. (1974).
  We have calculated the magnitude difference between HD 106384 and HD 106976,
which was the comparison star. The magnitude difference Var. minus Comp. for
filter No. 1 and the colour index (1-2) are plotted in Figure 1.
  Since this colour index (1-2) is an indicative of the temperature of the
star, we can deduce that FG Vir behaves as a typical delta Scuti variable, i.e.
maximum light occurs when maximum temperature. Furthermore, a Fourier analysis
of the data showed that there is at least a period of about 0.079d, which, via
a P-L-C relationship (Breger, 1979), leads to an absolute visual magnitude
of 1.73m. This value agrees very well with the M deduced from a purely 
photometric calibration of the Stromgren photometry; Philips et al. (1976), for
example, give for HD 106384, M_v= 1.60m.
  Therefore, we can conclude that FG Vir can be considered as a normal
delta Scuti variable, although more observations are needed in order to find the
whole periodic content of the star.


     P. LOPEZ DE COCA, R. GARRIDO, V. COSTA and A. ROLLAND

          Instituto de Astrofisica de Andalucia
          Apdo. 2144 Granada, Spain

References:

Breger, M. 1979, Pub.Astr.Soc.Pac., 91, 5 [BIBCODE 1979PASP...91....5B ]
Eggen, O.J. 1971, Pub.Astr.Soc.Pac., 83, 762 [BIBCODE 1971PASP...83..762E ]
Le Contel, J.M. Valtier, J.C., Sareyan, J.C., Baglin, A. and Zribi, G. 1974,
  Astron.Astrophys.Suppl., 15, 115 [BIBCODE 1974A&AS...15..115L ]
Philip, A.G.D., Miller, T.M. and Relyea, L.J. 1976, Dudley Observatory
  Reports No. 12 [BIBCODE 1976ahmc.proc.....P ]


                           [FIGURE 1]