Abstract. We present the first results of a 2-year high-resolution spectroscopy campaign of 59 candidate γ Doradus stars which were mainly discovered from the HIPPARCOS astrometric mission. More than 60% of the stars present line profile variations which can be interpreted as due to pulsation related to γ Doradus stars. For all stars we also derived the projected rotation velocity (up to more than 200 km s −1 ). The amplitude ratios 2K/∆m for the main HIPPARCOS frequency are in the range 35−96 km s −1 mag −1 . About 50% of the candidates are possible members of binary systems, with 20 stars being confirmed γ Doradus. At least 6 stars present composite spectra, and in all but one case (for which only one spectrum could be obtained), the narrow component shows line profile variations, pointing towards an uncomfortable situation if this narrow component originates from a shell surrounding the star. This paper is the first of a series concerning mode identification using both photometric and spectroscopic methods for the confirmed γ Doradus stars of the present sample.

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Using uvby − β photoelectric photometry obtained with the 0.84 m telescope of the Observatorio Astrónomico Nacional de San Pedro Mártir, México, we determined some of the physical characteristics, such as effective temperature and surface gravity of the high amplitude Delta Scuti star V2455 Cyg (=HD 204615). Newly determined times of maximum light gathered at the Observatorio Astrónomico Nacional de Tonantzintla, México with small 10 inch telescopes equipped with CCD cameras were combined with times of maxima in the literature, and used to study the secular variation of the pulsational period of the star.

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Abstract. We present spectroscopic and photometric observations of the star HD 173977. It appears that the star is part of a double line binary system, with a period of 1.801 d, corresponding to twice the period of the photometric variations. Hence the star is an ellipsoidal variable. The system is probably synchronized. The physical parameters of both components were derived through two independant methods, one based on evolutionary tracks, the other being the result of the behaviour of light curves in a close binary system. After removing the ellipsoidal variations, 3 frequencies are detected in the photometric data: 8.56, 14.51 and 16.42 d −1 , while 2 additional frequencies are also possible: 10.96 and 12.11 d −1 . In accordance with its position in the HR diagram, the primary component of HD 173977 should be considered as a δ Scuti star and no longer as a γ Doradus star. In addition, HD 173844, used as a check star, is discovered variable with a 15.79 d −1 frequency and is classified as a δ Scuti star.