Abstract. In July, 1999, the Hubble Space Telescope (HST) pointed for more than 8 days continuously at the globular cluster 47 Tucanae. Two guide stars were used during this campaign by the Fine Guidance Sensors (FGS). Using more than 19 million photometric FGS data for the guide star GSC 09137-03505 we found brightness variability corresponding to three approximately equidistant frequencies. The detected frequencies range from 21 to 71 µHz with amplitudes between 341 and 291 ppm. Multicolor CCD photometry was obtained at the Cerro Tololo Inter-American Observatory to derive color information for the guide stars. In addition, flux calibrated spectra were observed at the South African Astronomical Observatory. Temperature and surface gravity were determined from a comparison of observed and synthetic spectral fluxes using the  (Vienna New Model Grid of Stellar Atmospheres) model atmosphere grid developed by Heiter et al. (2002, A&A, 392, 619) and Nendwich et al. (2004, CoAst, 144, 43). We also performed linear nonadiabatic analyses of various stellar models in an attempt to interprete the frequencies.

Abstract. The existence of Maia variables has been in dispute since 1955. They are supposed to be located between the blue edge of the classical instability strip and the red border of the slowly pulsating B stars, hence in a domain of the HRD where no excitation mechanism for pulsation is yet known. But luminosity variations were discovered in time series of α Draconis, an A0iii Maia candidate star, with a period of about 53 minutes and an amplitude of less than 0.002 mag. Spectroscopic time series indicate radial velocity variations with the same period and an amplitude of about 40m s −1 . Alpha Dra is a single-lined spectroscopic binary with an orbital period of 51.4 days and a distance between the components of about 0.46 AU. Tidal interaction may therefore be responsible for pulsation. If true, the pulsation amplitude should be modulated with the orbit as is indeed indicated by recent observations.

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MOST and COROT are two satellite missions dedicated to asteroseismology and the detection of exoplanets. Both satellites use CCDs as a detector and hence they do not exclusively observe their prime targets but an entire field with additional objects. It is crucial to know their astrophysical properties and to have information on the location in the CCD-fields. Therefore VISAT (VIenna Selection of Astronomical Targets, see Kallinger et al., this volume) was used to investigate the fields around the prime targets of COROT and MOST resulting in the two catalogues described in this article.