COMMISSIONS 27 AND 42 OF THE IAU
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 4001

                                            Konkoly Observatory
                                            Budapest
                                            1 March 1994

                                            HU ISSN 0374 - 0676


      DISCOVERY OF SHORT TIME-SCALE OSCILLATIONS IN HD 74292


 The small amplitude variability of HD 74292 was discovered in December 1988 in the
course of the work on the Catalogue of WBVR Magnitudes of the Northern Sky Bright
Stars (Kornilov et al., 1991). The star has not yet been mentioned as variable in any
catalogues and lists of variable stars. Co-ordinates of the star are RA=8h44m14.89s
D=+32d03'45.1" (2000.0), spectrum A2, mean magnitudes and colours are V=7.032m,
B-V=0.233m, W-B=0.030m, V-R=0.211m.
 The photometric observations were carried out at Tien-Shan High-Altitude Observatory 
of Sternberg State Astronomical Institute with 48-cm reflector. Four-channel WBVR
photometer constructed by V. G. Kornilov and A. V. Krylov and single channel UBV
photometer constructed by the author of this paper were used. The total of nine sets of
observations were obtained on the following Julian Dates:

Set No.   J.D. 24...
1         47509.3008-.3843
2         47622.1753-.3027
3         47623.1284-.2812
4         48255.2734-.5098
5         48278.3701-.4854
6         48291.2607-.4219
7         49028.1445-.4611
8         49040.1016-.4468
9         49043.0877-.2814

 HD 75332 (Sp.: F7Vn, V=6.228m, B-V=0.526m, W-B=-0.127m, V-R=0.437m) was
used as a comparison star. The stability of this star is undoubted because it has been
checked many times during the photometric sky survey (Kornilov et al.,1991), the r.m.s.
error of a measurement is of 0.002m in V band. HD 74057 (Sp.:F8, V=7.201m, B-V=0.585m,
W-B=-0.099m, V-R=0.486m) was a control star.
 The light curves of HD 74292 in V band obtained during the last four sets of observations 
(Nos. 6-9) are shown in Figure 1. The deviations Delta V from the mean magnitude are
plotted against Julian Date. These curves demonstrate rapid oscillations with maximum
amplitude of 0.5m in V.
 A preliminary periodogram analysis was carried out using Deeming's (1975) and PDM
methods in the period range from 0.025d to 0.10d. The whole data set does not give definite
result. Sets 1-3 confirm variability but are not sufficient for independent period search.
Sets 4-6 show multiple peaks in the power spectrum with maxima near 0.080d and 0.046d.
Sets 7-9 show distinct variability pattern with predominating peak at 0.038m in the power
spectrum.

                             [FIGURE 1]

                     Light curves of HD 74292


  On the base of the spectrum, color indices and parameters of oscillations, HD 74292
may be classified as a delta Scuti type variable.



                          A. V. KUSAKIN
                          Tien-Shan High-Altitude Observatory
                          of Sternberg State Astronomical
                          Institute,
                          Kislovodskaya 34, Almaty,
                          480060, Kasakhstan


References:

Deeming, T. J., 1975, Astrophys. Space Sci., 36, 137 [BIBCODE 1975Ap&SS..36..137D ]
Kornilov, V. G., Volkov, I. M., Zakharov, A. I., Kozyreva, V. S., Kornilova, 
   L. N., Krutjakov, A. V., Krylov, A. V., Kusakin, A. N., Leontiev, S. E., 
   Mironov, A. V., Moshkaliov, V. G., Pogrosheva, T. M., Sementsov, V. N., 
   Khaliullin, Kh. F., 1991, Sternberg Astr. Inst. Trans. (Trudy), Vol. LXIII
   [BIBCODE 1991TrSht..63....1K ]