26.10.2022

Europe's galaxy mapper Gaia sent a strange signal that ground controllers first couldn't explain.

European Space Agency's veteran space telescope XMM-Newton captured the immediate aftermath of the gamma ray burst of the century. (Image credit: ESA/XMM-Newton/Pedro Rodriguez (Serco Gestión de Negocios S.L. for ESA - European Space Agency)/Andrea Tiengo (IUSS Pavi))

A fleet of space telescopes unexpectedly detected the record-breaking gamma-ray burst GRB221009A onOct.9, sparking concern among spacecraft operators about the blast's odd signal. 

The European Space Agency's (ESA) Gaia galaxy mapper sent a strange reading to its controllers on early afternoon, Oct. 9, showing a surprising amount of high-energy particles hitting the spacecraft's detectors. The engineers were puzzled for a while, ESA said in a statement(opens in new tab), but eventually realized that the spacecraft, built to measure precise positions of stars in our galaxy, detected the powerful gamma-ray burst GRB221009A which flashed at Earth from a distant world over 2 billion light-years away. 

Other ESA spacecraft picked up the signal, described as the most energetic gamma-ray burst ever detected, among them the sun-exploring Solar Orbiterand Mercury-bound BepiColombo. The data, ESA said in the statement, is still being analyzed.

ESA's probably best catch is an image of the gamma-ray burst's immediate aftermath taken by the agency's veteran spacecraft XMM-Newton, which, just like NASA's Swift observatory that spotted GRB221009A first, specializes in detecting high-energy X-ray radiation. 

XMM-Newton, in orbit since 1999, captured the mesmerizing rings around the source of the burst that are a result of the interaction between the energetic rays and the dust in our galaxy. 

ESA's gamma-ray observatory Integral, which celebrated 20 years in orbit earlier this month, imaged the waning source one day after the explosion, clearly detecting a still active region.

Data gathered by the satellites will help astronomers to learn all there is about this event, which has since been described as a "once-in-a-century" by astronomers.

European Space Agency's Integral spacecraft captured the aftermath of the most powerful gamma-ray burst ever recorded. (Image credit: ESA)

Gamma-ray bursts are the most energetic explosions known to occur in the universe apart from the Big Bang. Astronomers believe that these bursts mark the birth of black holes in supernova explosions of extremely massive stars. As a vast amount of material from the old collapsing star falls into the new-born black hole, the black hole gets rid of some of it in the form of a powerful jet that bursts into the surrounding space at nearly the speed of light. The jet is rather narrow and therefore the burst can be detected only in the parts of the universe where it aims. 

Satellites around Earth detect about one gamma-ray burst per day but only in about 30% cases can astronomers locate the burst's source. GRB221009A, however, was like none seen before, the energy of its photons temporarily blinding the sensitive gamma-ray detectors on specialist satellites. 

Quelle: SC