NIR (JHK) photometry of six quasars with redshifts ranging from 3 to 3.78 is reported. None of these objects has previously been observed in the IR. Their NIR colors are bluer than those of low-redshift quasars. They do, however, exhibit a considerable scatter, which can be qualitatively explained by line-emission contamination within the IR

Near-infrared maps in the J, H, and K bands, have been obtained for the nearby flocculent spiral NGC 2403, with a linear resolution of 900 pc. Radially and azimuthally averaged profiles, and profiles in colour index are presented. The maps and the annular profiles show the presence of near-infrared spiral arms, whose contrast with the disc is

New measurements of the lithium abundance in a sample of 37 field dwarfs of low metallicity (-0.6 ≥ [Fe/H] ≥ 3.2) are presented. Combining these observations with those in the literature it is shown that extremely metal-deficient ("EMD") dwarfs ([Fe/H] ≤ -1.4) form a much more homogeneous population with regard to 7Li abundance than stars somewhat

Following the work started in 1984 to detect the solar intensity oscillations from ground (Jimenez et al., 1986), simultaneous velocity and intensity observations of 16 contiguous days of very high atmospheric quality obtained at Izana (Tenerife) have been analyzed. The frequencies of the p-mode intensity spectrum at three channels (500, 680 and

The RS CVn noneclipsing system II Peg has been observed in the J, H, K, L, and M infrared bands along a complete period. The shape of the light curve shows an unusual size and concentration of the dark spots in one of the hemispheres of the star. Photometric spectral type K3 IV is derived for the unperturbed photosphere and M4 for the dark spots

We have observed six highly metal-deficient dwarfs in the spectral range containing the resonance doublet of 9Be II at 3130 Å. Using the method of spectral synthesis we have evaluated the abundance of 9Be in these objects. In three of the stars, those with metallicities [Fe/H] -1.5 we set upper limits to the 9Be abundance, 9Be/H, below 2.5 10-12