EX Hydrae is one of the earliest detected eclipsing binaries among the cataclysmic variables. The most striking property seen in the light curve of the star is the presence of a coherent large-amplitude periodic variation with a period of 67 min that is secularly decreasing. The existence of this shortening 67-minute cycle, in turn, is one of the prime reasons why EX Hydrae has been so intensively observed during the last decade. In this research the eclipsing dwarf nova EX Hydrae was monitored during 29 hours in Strömgren uvby, and, at the same occasion, during 45 hours in the B band of the Johnson system. We present these data (more than 18,000 discrete magnitudes) in extenso, and scrutinize their quality in relation to their future employment in an analysis of flickering.
On the CD-ROM are 2750 datapoints for the differential uvby light curves and 17,088 differential B measurements. In total approximately 0.7 Megabyte of data in ASCII tables. HJD approx. 3960--3972 (-2440000).
The North Galactic Pole Canada--France--Hawaii Telescope Catalogue of faint galaxies is made available. We provide positions, photometric and structural parameters for more than 50,000 galaxies. The J and F magnitudes were obtained from IIIaJ and IIIaF CFHT prime focus plates respectively. This catalogue have been used in many studies of faint galaxy properties. Galaxy counts, colour distributions and clustering properties of faint galaxies have been obtained with these data. Statistical properties of stars have been studied as well.
As part of a study of large scale structure at intermediate redshifts, a catalog of faint galaxies has been derived for a 2.2 square degrees area (maximum angular extent approx. 2.5×2.5 degrees) near the North Galactic Pole. Five IIIaJ and four IIIaF plates were obtained with the Canada--France--Hawaii Telescope in 1987. The mulsion/filter combinations were IIIaJ+GG385 [= Kron (1980) J mag around approx 4560 Å, and width approx 1560 Å and IIIaF+GG495 [= Kron (1980) F mag around approx 6000 Å, width approx 2000 Å.
The data encompass time-series spectra of a small number of early-type supergiants zeta Pup (O4 Iaf), P Cygni (B1p), HD169454 (B1 Ia+), zeta1 Sco (B1.5 Ia+), HD91619 (B7 Ia), beta Ori (B8 Ia), HD96919 (B9 Ia), HD92207 (A0 Ia), HD100262 (A2 Ia), α Cyg (A2 Ia), HD160529 (A2 Ia+), and eta Car (pec)) which have been obtained with a number of telescopes within the last years (between 1990 and 1994). In addition we present spectra of the Trapezium star theta1 Ori C (O7 V), which was included in our monitoring program. A total of 1719 spectra covering the wavelength range from 4000 to 6800 Å with a spectral resolution between 12,000 and 20,000 is presented. The data present a unique data base for the study of the variability of early-type supergiants on time scales from days to years.
Several classes of early-type emission-line stars, in particular supergiants and P Cygni-type stars are variable on long time scales, typically months and longer. Since the atmospheric velocities and particularly velocity variations are small (a few km/s only) for spectroscopic studies of these stars high spectral resolution is needed. Since traditionally high-dispersion spectrographs have been attached to large telescopes only, where typical observing runs are shorter than a week, the long time-scale variations of these stars are little studied with high dispersion and good coverage in time and wide spectral range. Only photographic data (with their well-known problems) are available over longer time scales for a few stars, e.g. P Cygni.
|Return to JAD page||Orderform||Return to Twin Press homepage|