Narrow Results

The observations of Betelgeuse since Christmas 2011 were started either to study the star and to contribute to observational astronomy from urban contexts, with high level of light pollution, using the naked eye. Since then 811 observations to November 9, 2021 have been made and communicated to the AAVSO international database. Antares and also other interesting long-period variable stars like VY CMa, RS Oph (recurrent nova), V766 Cen and several novae and SN2014J are part of the 2.5 K database of visual observations, obtained with the Argelander method applied to naked eye or telescopic observations. It is an invitation for the young generations, to contribute to these studies with careful and feasible observations, which require a reduction for airmass extinction of the variable star and of the comparison stars, when they are not on the same narrow field of view. The possibility to deduce the airmass by reading the notes (containing the location of the observation) of all the AAVSO-SGQ catalogue is finally presented as a point of force of my observations.

High energy transients make up a diverse and exotic class of objects, from terrestrial lightning to γ-ray bursts at cosmological distances. In this review, we provide a detailed look at some of the more exciting transients observed over the last few years by Swift and other high energy missions.

The theory of General Relativity deals with very accurate measurements that show significant divergences from Newtonian predictions only with speed near to the velocity of light. The photometry of the radiation from collapsing star’s shells like novae and supernovae is a starting point for relativistic cosmic phenomena. The visual observations described in this paper provided the needed photometrical and timing accuracy to follow these phenomena. More than 1200 observations of variable stars, included the type 1a SN2014J, Nova DEL 2013, Nova CEN 2013 and Nova SGR 2015 no. 2 have been sent to the AAVSO by the author, with SGQ code, during the period 1998-2015, and contributed also to IAU and HST observational campaigns; they have been analyzed to evaluate the photometric accuracy, in the context of the International Year of Light 2015.