We request 13.9 hours of IRS GTO time to observe two recently discovered very low-mass T dwarfs, the early-T HN PegB and the very late-T ULAS J0034. As inferred...

We propose to use the low spectral resolution capabilities of IRS to obtain high signal-to-noise mid-infrared spectra of a sample of 70 Ultra- and Hyperluminous...

The ESO 32-channel infrared (1 -5 micron-meter) grating spectrometer, IRSPEC, was put into operation and made available for Visiting Astronomers in October 1986...

We have derived beryllium abundances for all Li-rich giant stars known in the literature and visible from the southern hemisphere and 10 other Li-normal giants...

GRO J0422+32 (= V518 Per) is a black-hole X-ray nova which went into outburst on August 5, 1992. Since then, we have been monitoring the decay light curve of...

According to its spectral type B2 Ib/I I (Klare & Neckel 1977; Schmidt & Carruthers 1996), HD163899 is a supergiant star. The star presents p and g-mode...

NLTE effects in iron lines are carefully investigated for the sunspot umbral model of Maltby et. al. (1986). Our model atom is realistic: it has hundreds of...

As part of a long term observational project, we are investigating the macroturbulent broadening in O and B supergiants (Sgs) and its possible connection with...

The spectrum of O and B Supergiants is known to be affected by an important extra line-broadening (usually called macroturbulence) that adds to stellar rotation...