A visit to the H.E.S.S. observatory

Drukuj

Prof. Tomasz Bulik, Director of the UW’s Astronomical Observatory, was part of the Foreign Secretary’s delegation to Namibia. One of the highlights of the trip was a visit to the world’s largest ground-based gamma-ray observatory – the High Energy Stereoscopic System (H.E.S.S.). The University of Warsaw has been a member of the H.E.S.S. consortium for 20 years.

 

H.E.S.S. (High Energy Stereoscopic System) is one of the world’s most important astronomical observatories studying cosmic sources of the highest-energy gamma-ray radiation. Its most significant achievements include: the discovery of the first particle accelerator in the Galaxy capable of accelerating particles to energies of the order of PeV at the centre of the Milky Way, the detection of gamma-ray bursts (GRBs), the detection of cosmic rays, and research into dark matter. In recent years, the observatory has published ground-breaking results in the journals “Nature” and “Science”, concerning, amongst other things, the microquasar SS433, the new RS Ophiuchi, and the gamma-ray burst GRB 190829A.

 

The H.E.S.S. collaboration brings together over 200 scientists from 13 countries, with the University of Namibia (UNAM) as the key African partner, contributing to the operation of the observatory and the training of young researchers. Poland has been involved since 2006 through a consortium comprising the Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences (lead partner), the University of Warsaw, the Jagiellonian University, Nicolaus Copernicus University and the Institute of Nuclear Physics of the Polish Academy of Sciences. Polish scientists have played a significant role both in scientific discoveries and in the development of the observatory’s infrastructure, supplying components of the control system for the largest H.E.S.S. II telescope and some of the mirrors, as well as participating in the management of international collaboration. The observatory is one of the most prominent examples of long-term scientific cooperation between Europe and Africa, contributing to the development of technological and educational expertise in Namibia.

 

The H.E.S.S. team includes Prof. Tomasz Bulik, Director of the UW’s Astronomical Observatory, who, together with Prof. Rafał Moderski from the Astronomical Centre of the Polish Academy of Sciences, took part in the delegation led by Deputy Prime Minister and Minister for Foreign Affairs Radosław Sikorski to Namibia. Part of the trip, which took place from 30th June to 1st July, was a visit to the H.E.S.S. observatory.

 

 

“Minister Sikorski’s visit to the H.E.S.S. observatory is a tribute to the excellence of Polish astronomy and the significance of its presence in Africa and across the entire southern hemisphere. Over more than 20 years of operation, the H.E.S.S. telescope has pioneered and advanced gamma-ray astronomy. Before the observatory began operations, we knew of only one source of these rays; to date, H.E.S.S. has discovered over 200. Our work at H.E.S.S. contributes not only to the advancement of science but also to technological development in Poland, as evidenced by our involvement in the construction of the CTA (Cherenkov Telescope Array), which is currently being built in Chile and the Canary Islands,” says Prof. Tomasz Bulik.

 

 

A leader in sky surveys

The UW’s Astronomical Observatory (OA) is a leader both nationally and internationally in the field of large-scale photometric sky surveys. This is thanks to the OGLE and ASAS projects, which have been running for over a dozen years.

In addition to H.E.S.S., employees of the UW’s Astronomical Observatory are also actively involved in such world-renowned projects as Araucaria, CTA, LIGO/VIRGO and the Planck and Gaia satellite missions.

 

Key achievements of the UW scientists in the field of astronomy:

 

  • discoveries made as part of the OGLE (Optical Gravitational Lensing Experiment) project, including:
  • the detection of the first instances of gravitational microlensing and the development of this pioneering field of astrophysical research (around 20,000 instances of gravitational microlensing discovered over the project’s 30-year history);
  • unique new stars, dwarf novae and supernovae;
  • a unique map of interstellar reddening towards the Magellanic Clouds (2021);
  • in 2020, astronomers from the OGLE team announced in Astrophysical Journal Letters the discovery of the smallest free-floating planet found to date;
  • demonstrating that dark matter does not form compact objects;
  • further ground-breaking discoveries have been made in the field of exoplanet searches. For the first time, two new planet-hunting techniques were successfully applied: the transit method and gravitational microlensing. To date, over 70 exoplanets have been discovered;
  • in 2019, a team of astronomers from the UW’s Astronomical Observatory, working as part of the OGLE project, presented a unique three-dimensional map of the Milky Way in the journal Science. The map provides a precise picture of our Galaxy and offers a wealth of new information regarding the structure and history of the stellar system in which we live;
  • as part of the OGLE project, the world’s largest catalogue of variable stars, comprising over a million objects, has been compiled. It contains many unique stellar systems and previously unknown types of stellar variability. Explosive objects are also regularly discovered, notably the discovery of the first extrasolar ice giant – the planet OGLE-2008-BLG-092Lb (2014);
  • the discovery, using the gravitational microlensing method, of the planetary system OGLE-2007-BLG-349 (2007). A few years later, an international team of scientists proved that the planet orbits a binary star system;
  • the discovery of the largest ‘Polish’ asteroid, Dziewanna – 500 km in diameter;
  • the demonstration of the existence of a new class of exoplanets – free-floating planets;
  • participation in the European Space Agency’s Gaia space mission and the discovery of black holes in our galaxy;
  • participation in research into gravitational waves detected by the LIGO and VIRGO detectors;
  • work on the detector of the future – the Einstein Telescope;
  • participation in the Vera Rubin Observatory project, a new 8-metre telescope in Chile.