Sources responsible for volcanic unrest produce characteristic surface deformation. Given a sufficient number of distributed observation points, inversion is the preferred procedure for retrieving the source parameters of location and volume or pressure change. Most often the solutions have been for point sources embedded in a homogeneous half

Context: Planetary Nebulae (PNe) display complex radial surface brightness profiles whose understanding is crucial for a correct interpretation of their formation and evolution. In particular, the intermediate shells commonly observed around the bright rims of PNe contain important information for the discussion of the mass loss rate at the end of

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

We present 45 ground-based photometric observations of the K2-22 system collected between 2016 December and 2017 May, which we use to investigate the evolution of the transit of the disintegrating planet K2-22b. Last observed in early 2015, in these new observations we recover the transit at multiple epochs and measure a typical depth of

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