It is now about 30 years ago that photometric and spectroscopic surveys of asymptotic giant branch (AGB) stars in the Magellanic Clouds (MCs) uncovered the first examples of truly massive (> 3-4 M_ȯ) O-rich AGB stars experiencing hot bottom burning (HBB). Massive (Li-rich) HBB AGB stars were later identified in our own Galaxy and they pertain to

We present the preliminary results from observing the nearby radio galaxy M 87 for 156 hours (between the years 2012 and 2015) with the MAGIC telescopes, which lead to a significant very high energy (VHE, E > 100 GeV) detection of the source in quiescent states each year. Our VHE analysis combined with quasi-simultaneous data at other energies

The description of dust production by asymptotic giant branch stars (AGB) is matter of interest for a wide part of the astronomical community. In the light of this, the number of studies focused on this topic rapidly increased in the last decade. Latest releases of hydrodynamical models provide a deep insight of wind structure and mass loss process

Observations of H2O isotopologues of the extreme OH/IR star OH 26.5+0.6 show that the star has an initial mass consistent with it being an intermediate-mass star. The Herschel-HIFI spectra show clear detection of H216O and H217O while H218O is missing, consistent with the prediction of hot bottom burning which occurs in stars with an initial mass

The blazar QSO B0218+357 is the first gravitationally lensed blazar detected in the very high energy (VHE, E > 100 GeV) gamma-ray spectral range (Ahnen et al. 2016). It is gravitationally lensed by the intervening galaxy B0218+357G (z l = 0.68466 +/- 0.00004, Carilli et al. 1993), which splits the blazar emission into two components, spatially

We have explored the circumstellar effects on the Li abundance determination in a complete sample of O-rich Galactic asymptotic giant branch (AGB) stars, previously studied with hydrostatic models. We use a modified version of the spectral synthesis code Turbospectrum and more realistic extended model atmospheres that consider the presence of a