COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                    Number 1526

                                 Konkoly Observatory
                                 Budapest
                                 1978 December 29




    HR 5492: A NON-RADIAL PULSATING DELTA SCUTI STAR ?


   HR 5492 is a F2IV star which was classified as a Delta Scuti
star by Percy (1973) on the ground of five hours of photoelectric 
observations. We observed the star for three nights in the
spring of 1978 with the 1 m reflector of the Merate Observatory.
The comparison star was HD 130173 and the check stars were
HD 129226 and HD 129865. The results are represented in the
Figure, where each point is the mean of about nine individual
observations (comparison minus variable) and the bars represent
two standard deviations.
   These data were then analysed to search multiple periodicity
with the Vanicek method (1971). From this analysis two sinusoidal
components were found unambiguously. Their periods are P_1=0.0825d
and P_2=0.0837d and the semi-amplitudes are A_1=0.014m+-0.003 and
A2=0.013m+-0.003, respectively. The synthesized light curve, which
was computed with this solution, is represented with the full
line in the Figure.
   The ratio between the two periods is P_1/P_2=0.986. Such value
would suggest that non-radial pulsational modes are working in
this star, as no low-order radial modes in a Delta Scuti star
would agree with the above ratio (Petersen et al., 1972). A
similar ratio was found by Shobbrook and Stobie (1974) for 1 Mon.



         G. GUERRERO, L. MANTEGAZZA, M. SCARDIA
         Osservatorio Astronomico, Via E. Bianchi, 46
         I-22055 Merate (Como), Italy




References:

Percy, J.R., 1973. Journ.Roy.Astron.Soc.Can., 67, 139 [BIBCODE 1973JRASC..67..139P ]
Petersen, J.O., Jorgensen, H.E., 1972. Astron.&Astrophys., 17, 367 [BIBCODE 1972A&A....17..367P ]
Shobbrook, R.R., Stobie, R.S., 1974. "Stellar Instability and Evolution"
      I.A.U. Symp. No. 59, 67 [BIBCODE 1974IAUS...59...67S ]
Vanicek, P., 1971, Astrophys.Spa.Sci., 12, 10 [BIBCODE 1971Ap&SS..12...10V ]


                       [FIGURE 1]