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The effect of temperature fluctuations in the spectra of ionized nebulae was firstly explored by Peimbert (1967). Since then, the problem of their existence has remained an open question. In fact, there are observations and models that argue both in favor and against such fluctuations and these are reviewed in this paper. We also discuss the

We report on an approximately twelve hour long X-ray flare from the low-mass X-ray binary KS 1731-260. The flare has a rise time of less than 13 min and declines exponentially with a decay time of 2.7 hours. The flare emission is well described by black-body radiation with peak temperature of 2.4 keV. The total energy release from the event is 1042

In this contribution, we show the capability of STARE to obtain frequencies and amplitudes from high temporal resolution δ Scuti spectra. Lightcurves of 13 new field δ Scuti stars are analyzed and a total of 21 oscillation modes are found in a single field. Noise level in the spectra falls bellow 3 mmag for stars fainter than magnitude 9

We present Very Large Telescope (VLT) low-resolution spectroscopy of the neutron star X-ray transient XTE J2123-058 during its quiescent state. Our data reveal the presence of a K7V companion which contributes 77 per cent to the total flux at λ6300 and orbits the neutron star at K2=287+/-12kms-1. Contrary to other soft X-ray transients (SXTs), the

We have obtained series of continuous differential photometry in the J and KS bands for several L-type dwarfs. We intend to search for photometric variability in order to: - investigate the variability amplitude associated to atmospheric changes in time-scales from minutes to several hours, - investigate rotation periods through light curve