However, this upgrade will likely be implemented in several stages, with periods of data collection in between and a new observation campaign starting in late summer/early autumn 2026 and lasting approximately six months.

⏩ The LIGO, Virgo and KAGRA interferometers are preparing for a new phase of technological upgrades and testing over the next few years.

Virgo has played a crucial role, contributing to the detection and characterization of numerous signals. The success of the O4 run reflects the strength of international collaboration and the relentless effort of our teams to push the boundaries of such challenging measurements.”

“The completion of O4 marks a historic milestone: the longest observing run ever conducted by the global gravitational-wave network - said Gianluca Gemme, spokesperson for the Virgo Collaboration and researcher at @INFN_

"These discoveries highlight, once again, the crucial role of the international network of gravitational interferometers in unravelling the most elusive phenomena in the universe."

Image credits: Carl Knox, OzGrav, Swinburne University of Technology

"GW241011 and GW241110 teach us that some black holes do not just exist as isolated partners, but probably as members of a dense and dynamic crowd." said Gianluca Gemme, researcher INFN and spokesperson of the Virgo Collaboration

These phenomena usually occur in very dense and crowded cosmic environments, such as star clusters, where black holes are more likely to collide and merge repeatedly 💥

They are black hole mergers in which the values of the spin, i.e. the rotation parameters, and the masses of the black holes suggest that they have themselves been generated by previous mergers and are therefore 'second-generation' 🧐

In the picture from left to right Nicolas Leroy (CNRS), Joël Groeneveld (FNRS), Jorgen D’Hondt (Nikhef/NWO-I), Marco Pallavicini (INFN), Massimo Carpinelli (EGO Director), Hans Plets (FWO)

EGO, the European Gravitational Observatory, was created 25 years ago by the Italian INFN and the French @cnrs.fr, later joined by @nikhef.bsky.social (Netherlands). This year two new institutions, based in Belgium, joined the consortium: @fwovlaanderen.bsky.social and FNRS 🌍

This can be limited using “squeezing”, a technique manipulating light at the quantum level, effectively “cooling down” the relative movement of the mirrors to a few millionths of a degree above Absolute Zero

LIGO, Virgo and KAGRA constantly battle with quantum effects on their mirrors (objects weighing more than 40 kg!), such as quantum radiation pressure noise, that is, fluctuations of the laser field that causes the mirrors to jitter.

Even the extreme precision of the measurements required to detect gravitational waves explores and pushes the boundaries of the quantum world.

Quantum mechanics is an extraordinary theory which, more than a century after its initial formulation, continues to surprise us and whose consequences can still be explored in many areas of physics.

People of all ages got to learn about these extraordinary signals through which the universe tells its story and how we listen to them 👂

Barcelona, Rome, Paris, Warsaw, Madrid, Milan, Pisa, Olbia, Cascina, Bologna , L’Aquila, Napoli, Perugia, Trieste: these are only some of the cities where researchers of the Virgo Collaboration organized activities 🤯

📹 The video shows the then Virgo collaboration spokesperson Fulvio Ricci, @INFN_ researcher and professor at Sapienza University of Rome, announcing this important discovery, followed by the signal detected in September 2015.

This opens up extraordinary new scientific challenges that we will only be able to tackle in the coming years thanks to an increasingly broad and solid collaboration between different scientists, countries and institutions, both at European and global level."

"We are living an extraordinary moment for gravitational wave research: thanks to instruments such as Virgo, LIGO and KAGRA, we can explore a dark universe that was previously completely inaccessible. - said Massimo Carpinelli, professor at Milano Bicocca University and director of EGO