We report on the results of a coordinated observation of Mrk 421 during outburst using data from XMM-Newton and ground-based TeV data from two Imaging Air Cherenkov Telescopes, the Whipple 10m telescope, based in Arizona, and the MAGIC telescope, based on La Palma in the Canary Islands. The coordinated effort between the two TeV groups allowed for

We have searched for possible sites in Argentina for the installation of large air Cherenkov telescope arrays and water Cherenkov systems. At present seven candidates are identified at altitudes from 2500 to 4500 m. The highest sites are located at the NW of the country, in La Puna. Sites at 2500 and 3100 m are located in the West at El Leoncito

Slow earthquakes and afterslips prove that the Earth does not have just two response time scales, i.e. that of tectonic loading and that of regular earthquakes. A swarm of slow earthquakes, with time constants of the order of hundreds of seconds, has been detected by a laser interferometer below the Gran Sasso massif (Italy). We analyse and model

Context. Light bridges are convective intrusions in sunspots that often show enhanced chromospheric activity. Aims: We seek to determine the nature of flux emergence in a light bridge and the processes related to its evolution in the solar atmosphere. Methods: We analyse a sequence of high-resolution spectropolarimetric observations of a sunspot

We explore the stellar structure of the Large Magellanic Cloud (LMC) disk using data from the Survey of the MAgellanic Stellar History and the Dark Energy Survey. We detect a ring-like stellar overdensity in the red clump star count map at a radius of ∼6° (∼5.2 kpc at the LMC distance) that is continuous over ∼270° in position angle and is only

Context. Research on supernovae (SNe) over the past decade has confirmed that there is a distinct class of events which are much more luminous (by 2 mag) than canonical core-collapse SNe (CCSNe). These events with visual peak magnitudes ≲-21 are called superluminous SNe (SLSNe). The mechanism that powers the light curves of SLSNe is still not well