Relativistic jets are observed across the entire electromagnetic spectrum in a variety of astrophysical systems, such as active galactic nuclei (AGNs), gamma-ray bursts (GRBs), and some black hole X-ray binaries, being launched from compact objects (black holes or neutron stars) typically surrounded by accretion discs. They are well-collimated outflows of plasma and fields, propagating with velocities close to the speed of light. Relativistic jets are supersonic, producing shocks that lead to a turbulent magnetic field, which can play an important role in acceleration of jet particles. They are also sources of kinetic instabilities driven by currents and shears as well as magnetic reconnection.

On July 31, 2025, the University of Tokyo completed excavation of the colossal cavern that will house the main detector volume of Hyper-Kamiokande, a next-generation, ultra-large water Cherenkov detector currently under construction in Hida City, Gifu, Japan.

On November 23, 2023, the LIGO-Virgo-KAGRA (LVK) collaboration detected GW231123, a gravitational-wave signal likely caused by the merger of two black holes with the highest combined mass the LVK collaboration has ever observed. These black holes would have been spinning incredibly fast, and their individual masses appear to fall into a range that challenges existing theories about how massive stars evolve and end their lives.

Object from outside the Solar System is just passing through it at high speed.

The visible light detected by our eyes is only a small fraction of the entire electromagnetic spectrum. It also includes radio waves, infrared, ultraviolet, X-ray, and gamma radiation. Combining observations in different ranges of electromagnetic waves allows astronomers to get a better understanding of what's going on in different objects in the Universe.

The Rector of the Jagiellonian University announces a competition for the position of assistant professor in the research staff group at the Astronomical Observatory of the Faculty of Physics, Astronomy and Applied Computer Science of the Jagiellonian University.

The lists of winners of this edition of the Competition are now public.

Research conducted by the student Aleksander Lenart from our Observatory suggests that black holes could power gamma-ray bursts.