We present calibrations of the effective temperatures of giant stars versus [Fe/H] and colours (U-V), (B-V), (R-I), (V-R), (V-I), (V-K), (J-H), (J-K), (I-K), (V-L'), (b-y) and (u-b). These calibrations are based on a large sample of field and globular cluster stars which roughly cover spectral types from F0 to K5. Their effective temperatures

We derived photospheric parameters, mass-loss rates, and wind velocities of Galactic O6-O7 stars by analyzing high-resolution spectra in the far-UV and UV ranges with line-blanketed, hydrodynamic, non-LTE spherical models. We combined spectra from the Far Ultraviolet Spectroscopic Explorer (FUSE) in the range 905-1187 Å and International

The effects of seeing on Sérsic r1/n profile parameters are extensively studied using a Moffat function. This analytical approximation to the point spread function (PSF) is shown to provide the best fit to the PSF predicted from atmospheric turbulence theory when β~4.765. The Moffat PSF is additionally shown to contain the Gaussian PSF as a

ELMER is a multi-purpose instrument for the GTC designed for both, imaging and spectroscopy in the visible range. The detection subsystem consists of a single E2V Technologies CCD44-82 detector mounted in a LN[2] cooled CCD camera and a SDSU-II CCD controller with parallel interface. The design including the low-noise fan-out electronics has been

Recently, huge photometric databases are being obtained for the Magellanic Clouds and other Local Group galaxies. These data allow, not only to study in great detail the star formation history of these systems, but also provide important information on details of stellar evolution theory. In the case of the LMC, two structures not previously

We present the results of a comparison between the environments of (1) a complete sample of 46 southern 2-Jy radio galaxies at intermediate redshifts (0.05 z 0.7), (2) a complete sample of 20 radio-quiet type-2 quasars (0.3 ≤ z ≤ 0.41), and (3) a control sample of 107 quiescent early-type galaxies at 0.2 ≤ z 0.7 in the Extended Groth Strip. The