We report four colour CCD photometry and photoelectric photometry of 3C 345 taken in the spring of 1990. After an initial partial recovery from the minimum observed in 1989 which was, at that time, the deepest ever recorded, a very fast decline to even fainter levels was seen over ten days in May 1990, which was then followed by a further partial

Extensive infrared observations were taken of OJ 287 in 1993/94 as part of an on-going monitoring campaign of this object started in 1988. The data show that this blazar reached very high levels in the infrared in Fall'94 after a continuous increase in brightness through the winter and spring of 1993/94. The infrared fluxes registered at maximum

Many barred galaxies show a set of symmetric enhancements at the ends of the stellar bar, called ansae, or the "handles" of the bar. Ansa bars have been in the literature for some decades, but their origin has still not been specifically addressed, although they could be related to the growth process of bars. But even though ansae have been known

Traditionally the Earth's reflectance has been assumed to be roughly constant, but large decadal variability, not reproduced by current climate models, has been reported lately from a variety of sources. We compare here the available data sets related to Earth's reflectance, in order to assess the observational constraints on the models. We find a

We use data from the Tenerife 10-, 15- and 33-GHz beam-switching experiments along with the COBE 53- and 90-GHz data to separate the cosmic microwave background (CMB) signal from the Galactic signal, and create two maps at high Galactic latitude. The new multi-MEM technique is used to obtain the best reconstruction of the two channels. The two maps

Because of the intense brightness of the OB-type multiple star system σ Ori, the low-mass stellar and substellar populations close to the centre of the very young σ Orionis cluster is poorly know. I present an IJHK_s survey in the cluster centre, able to detect from the massive early-type stars down to cluster members below the deuterium burning