A binary star system located 5,000 light-years away from Earth that explodes in a spectacular nova every 15 years has been captured by the MAGIC telescopes . Thanks to these powerful devices located at the Roque de los Muchachos Observatory in La Palma (Canary Islands), astronomers from the Max Planck Institute in Germany were able to study the observations of this pair of stars found in the Serpent Bearer constellation and it is formed by a white dwarf and a red giant that are about to end up becoming a supernova.
It is the first time that we capture such an event
The RS Ophiuchi nova emits a massive explosion, sending particles flying outward at close to the speed of light once every 15 years. The explosion occurs when the white dwarf “steals” (hence the nickname ‘vampire star’) gas from its nearby companion star. The last explosion from the binary star system occurred last year and the dramatic event was captured by two ground-based telescopes located in the Canary Islands , marking the first time this rare event has been captured – in which, when enough pressure builds up on the surface of the white dwarf being engulfed explodes – in such detailed gamma-ray observations.
Gamma rays emanate from protons that are accelerated to very high energies in the shock front that follows the explosion; this suggests that novae are also a ubiquitous source of cosmic radiation in the universe , consisting mainly of energy-rich protons, streaming through space at nearly the speed of light. A combination of measurements taken by ground-based telescopes suggests that the gamma rays come from energetic protons, the nuclei of hydrogen atoms.
massive thermonuclear explosion
The MAGIC telescopes allowed the researchers to measure the radiation coming from the explosion at 250 gigaelectronvolts , among the highest energies ever measured in a nova. By comparison, this radiation is 100 billion times more powerful than a beam of visible light.
“The spectacular eruption of RS Ophiuchi shows that the rapid response of the MAGIC telescopes really pays off: it takes them no more than 30 seconds to move to a new target,” says David Green, a scientist at the Max Planck Institute for Physics and Sciences and one of the authors of the study published in the journal Nature Astronomy.
This discovery could help solve one of the greatest mysteries of our universe: the puzzle of cosmic rays. First discovered in 1912 by Austrian physicist Victor Hess, cosmic rays have become a timeless reminder of how little we know about our cosmos.
We know that cosmic rays rain down on Earth at the speed of light and interfere with our technology, such as satellites or radio communications. But, despite being able to see, measure and study them, scientists are not very clear about where n comes from . To fully understand the complicated interaction of violent events with the interstellar medium in the Milky Way, more observations like those of RS Ophiuchi will be needed.
“This also makes nova outbursts a source of cosmic rays,” says David Green. “However, they tend to play the role of local heroes, meaning they only contribute to cosmic rays in the immediate neighborhood. The big players for cosmic rays are supernova remnants. Shock fronts created by stellar explosions They’re much more violent compared to novae.”
In the future, the researchers intend to continue using the MAGI C telescopes and see if they are capable of capturing gamma rays from violent events much closer to our planet.
Therefore, the MAGIC collaboration will continue to search for such objects in our galaxy and beyond to gain a better understanding of the origin of the mysterious cosmic rays.
Referencia: David Green, Proton acceleration in thermonuclear nova explosions revealed by gamma rays, Nature Astronomy (2022). DOI: 10.1038/s41550-022-01640-z. www.nature.com/articles/s41550-022-01640-z
