Recent high-resolution observations of sunspot oscillations using simultaneously operated ground- and space-based telescopes reveal the intrinsic connection between different layers of the solar atmosphere. However, it is not clear whether these oscillations are externally driven or generated in situ. We address this question by using observations

Observations have been selected in Tenerife Zodiacal Light Data, which make it possible to separate the diffuse galactic light from other components. Far from the Milky Way (30°≤|b|≤60°) the diffuse galactic light shows a decreasing slope which cannot exceed -0.3S 10 vis. per degree of galactic latitude, and is probably a very weak component of the

Not Available

We present a total of 12,436 photometric measures of 371 field stars of 26 quasars in the visible (UBVRI) and 22,276 photometric measures of 122 field stars of 13 quasars in the near-infrared (JHK), giving a total of 34,712 measures. Of these, 115 stars in 12 fields are calibrated in both ranges. One further field, Mrk 421, was calibrated, but on

The BL Lacertae object AO 0235+16 is well known for its extreme optical and radio variability. New optical and radio data have been collected in the last four years by a wide international collaboration, which confirm the intense activity of this source: on the long term, overall variations of 5mag in the R band and up to a factor 18 in the radio

We present the optical and UV emission-line properties of 160 X-ray-selected active galactic nuclei (AGN) taken from the RIXOS survey (including Hα, Hβ, [Oiii] lambda5007, Mgii lambda2798 and Ciii] lambda1909). This sample is believed to contain a mixture of absorbed and unabsorbed objects, with column densities up to ~4x10^21cm^-2. Although the