High-cadence observations by the slit-jaw (SJ) optics system of the sounding rocket experiment known as the Chromospheric Lyman Alpha Spectropolarimeter (CLASP) reveal ubiquitous intensity disturbances that recurrently propagate in either the chromosphere or the transition region or both at a speed much higher than the speed of sound. The CLASP/SJ

We report on an ongoing study of disk galaxy merger simulations and their implications for the Fundamental Plane (FP) of elliptical galaxies.

After the early observations of the disrupted asteroid P/2016 G1 with the 10.4 m Gran Telescopio Canarias (GTC) and modeling of the dust ejecta, we have performed a follow-up observational campaign of this object using the Hubble Space Telescope (HST) during two epochs (2016 June 28 and July 11). The analysis of these HST images with the same model

We report on long-term multiwavelength monitoring of blazar Mrk 421 by the GLAST-AGILE Support Program of the Whole Earth Blazar Telescope (GASP-WEBT) collaboration and Steward Observatory, and by the Swift and Fermi satellites. We study the source behaviour in the period 2007-2015, characterized by several extreme flares. The ratio between the

On the basis of a new photometric analysis of the Local Group dwarf irregular galaxy NCG 6822 based on observations obtained with the Advanced Camera for Surveys onboard the Hubble Space Telescope, we have obtained a new estimate of the extinction of two fields located in the southeast region of the galaxy. Because of significant differences in the

In order to develop a reliable method of distance determination of W UMa-type stars, a catalogue of light curve solutions of 159 systems has been compiled. The rate of transferred luminosity from the primary star to the secondary star was determined based on the catalogue data. This quantity has an important role in the distance determination. The