The first Hungarian and the smallest astrophysical space observatory in the world set out to track down the most powerful bursts in the Universe. With the GRBAlpha nanosatellite built under the leadership of experts at the Konkoly Observatory of ELKH Research Centre for Astronomy and Earth Sciences and launched into space in the spring of 2021, scientists managed to accurately determine the peak value of the gamma-ray burst GRB 221009A. This event could hardly been characterized with larger instruments due to detector saturation. Several subsystems of the GRBAlpha, including the detector that captured this event of October 9, 2022, were developed by researchers from the Konkoly Observatory in collaboration with Japanese, Slovak and Czech partners. The mission is currently being operated in cooperation with Masaryk University in Brno and the Technical University of Košice. The paper covering the measurement results related to the event of GRB 221009A, as well as a paper about the GRBAlpha detector design, system description and satellite operations have both been accepted for publication in the Astronomy and Astrophysics scientific journal. Among the authors at the Konkoly Observatory were project leader András Pál, electronic system engineer László Mészáros, director general László Kiss, and Balázs Csák, designer of satellite receivers and ground stations.
Gamma-ray bursts are among the most powerful and intriguing phenomena in the Universe. By studying them, we can gain insights into the final explosions of massive stars and the birth process of black holes. The most powerful gamma-ray burst ever detected and successfully recorded in human history was the event designated as GRB 221009A, observed on October 9, 2022. This burst was detected by many large instruments, including the Fermi Gamma-Ray Observatory operated by NASA. However, the peak value of the burst could not be precisely determined by these larger instruments due to their oversaturation.
The smallest satellite ever built for astrophysical purposes, the GRBAlpha nanosatellite constructed at the Konkoly Observatory and launched into space in the spring of 2021, was able to accurately determine the peak value of this extremely bright source thanks to its small size of 10 × 10 × 10 centimeters and innovative detector structure. Researchers at the Konkoly Observatory developed several subsystems of the GRBAlpha, including the detector that captured the 2022 gamma-ray burst mentioned earlier, in a Hungarian-Japanese-Slovak-Czech collaboration, and the mission is currently being operated in partnership with Masaryk University in Brno and the Technical University of Košice. According to András Pál, research advisor at the Konkoly Observatory and lead developer of the GRBAlpha satellite's detector system, these results show that even the smallest satellite instruments can not only contribute effectively to scientific projects but also serve as important complementary outputs to larger satellite missions.
Using the GRBAlpha nanosatellite, researchers were not only able to record the GRB 221009A event, but also detected dozens of similar, smaller gamma-ray bursts, high-energy solar flares that drive space weather and eruptions of active stars. Several institutes in many countries plan similar small satellite missions to be launched in the near future. It is a remarkable achievement on a global scale that GRBAlpha is the first instrument in this category, paving the way for other similar initiatives.
The big and the small: the large NASA satellites that captured the GRB 221009A gamma-ray burst and the GRBAlpha (Source: Francis Reddy / NASA Goddard, University of Maryland)