COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                        Number 2719

                                          Konkoly Observatory
                                          Budapest
                                          13 May 1985

                                          HU ISSN 0374 - 0676

       NO CEPHEID-LIKE VARIABILITY IN SAO 096478 = NSV 03374



  SAO 096478 (9.2, K0) is the star designed as "O" in the C4 Harvard Standard
Region. Its variability was suspected by Balz Jr. and Vyssotsky (1958) : "Both
the photographic and photovisual magnitudes of this star show larger than
average residuals (...). The star is probably a Cepheid". The spectrum varies
from F5 to K0 (Balz Jr. and Vyssotsky and references therein). The star is
named NSV 03374 as a suspected variable (Kholopov, 1982).
  Taking into account the wide spectral variation, a period longer than 15 d
and an amplitude of about 1.0 mag. is expected from a classical Cepheid, but
a first contradiction arises from the G5 V spectrum recorded by Nassau and
Mac Rae (1955).
  Such an amplitude is large enough to allow detection by a visual observer:
a tentative visual survey conducted by one of us (Le Borgne, 1983) during
1983 spring failed to show evidence of any significant   variation (probable
error : 0.2 mag.) discouraging further visual monitoring on larger scale by
GEOS observers.
  In order to have a definitive answer, NSV 03374 was photoelectrically
observed in 7 nights with the 50 cm telescope of Merate Observatory, in a
program concerning the study of variable stars of intermediate and late
spectral type.
  SAO 096482 (8.5, K0) was used as comparison star, SAO 096459 (9.2, G5) as
check star. The integration time was set to 20 sec. Table I shows DeltaV values
in the sense 'comparison minus variable' ; sigma is the standard error. If any,
the variation is smaller than 0.02 mag., but NSV 03374 is probably constant
since the same scatter is observed for the check star.
  The puzzle of the spectral variation cannot be solved with a simple
misidentification, because SAO 096469 (9.1, F5) and SAO 096494 (9.3, F5) are
30' northern to NSV 03374. In any case, the spectral features are not typical
of a Cepheid (or SRd) variable or of an RS CVn activity.
  Acknowledgements : thanks are due to Dr. A. Figer for advice about
visual results.





                             Table I
           
     DeltaV values for NSV 03374 and the check star
               NSV 03374     SAO 096459
      JD     DeltaV   sigma  DeltaV     sigma


    46069.44  -0.867  0.006         -
    46095.50  -0.872  0.008  -0.942    0.008
    46096.43  -0.849  0.006  -0.929    0.007
    46116.47  -0.882  0.007  -0.951    0.006
    46118.34  -0.854  0.013  -0.933    0.006
    46119.35  -0.857  0.007  -0.915    0.006
    46144.36  -0.863  0.006  -0.936    0.007





    E. PORETTI                                J.F. LE BORGNE
    Osservatorio Astronomico di Brera         GEOS
    Via E. Bianchi, 46                        12, rue Bezout
    22055 Merate (CO)                         75014 Paris
    Italia                                    France





References ;
Balz Jr., A.G.A., Vyssotsky, A.N., 1958, A.J., 63, 474 [BIBCODE 1958AJ.....63..474B ]
Kholopov, P.N., 1982, New Catalogue of Suspected Variables [BIBCODE 1982ncss.book.....K ]
Le Borgne, J.F., 1983, GEOS NC 379
Nassau, J.J., MacRae, D.A., 1955 Ap.J., 121, 32 [BIBCODE 1955ApJ...121...32N ]