We consider here a representative set of delta Scuti stars observed in the Praesepe cluster, thanks to recent efforts of multi-site networks. We show that the effect of rotation on the determination of fundamental parameters {Mbol} and {Teff} cannot be neglected when modelling fast rotators as delta Scuti stars. We propose a method to take this

We report the first reliable measurement of the nebular [O i] lambda 5577 emission line in the Orion nebula. Diagnostic diagrams based on the [O i] lambda lambda 5577, 6300, and [N i] lambda lambda 3467, 5198, 5200 emission lines indicate that the bulk of the nebular emission in the partially ionized zone of the Orion nebula is produced in regions

We present lithium observations of 35 stars previously reported by Wichmann et al. (1996) to be possible new weak T Tauri stars (WTTS) discovered by ROSAT in the Taurus-Auriga star-forming region. These stars were identified on the basis of low-resolution optical spectra. We have used our higher resolution spectra for measuring the equivalent

The eighth STEPHI international multi-site campaign was devoted to the δ Scuti Star V647 Tau of the Pleiades Cluster and was carried out in the period 1997 Nov 19-Dec 13. Analysis using two methods gave the same result. Five pulsation frequencies including both radial and non-radial modes are excited in this star. The dominant frequency p = 20.408c

We are continuing a comprehensive systematic study of the properties of Wolf-Rayet Galaxies (WRGs) based on data from ground and space observatories. In this proposal we request time on the KPNO 0.9m and 2.1m telescopes to undertake CCD imagery and spectroscopy of a group of WRGs. Our basic aim is threefold: (a) identify and characterize the

Six BL Lac objects from the complete 1 Jy radio-selected sample of 34 objects were observed in cycle 5 with the Hubble Space Telescope (HST) Wide-Field Planetary Camera 2 (WFPC2) to an equivalent limiting flux of mu_I~26 mag arcsec^-2. Here we report results for the second half of this sample, as well as new results for the first three objects