First detection of a radioactive particle in space

Astronomers have made the first unequivocal detection of a radioactive particle in interstellar space. The aluminum isotope was ejected into space after the collision of two stars, and was discovered by a team of researchers led by the Pole.

New data collected with the help of a radio telescopeoin ALMA and NOEMA unequivocally pointed to the radioactive isotope aluminum-26. This radioactive nuclide is found in interstellar space in molecules of aluminum-26 monofluoride.

Researchers believe that the radioactive compound was ejected into space by a collision of twooch stars. Scientists found it in matter surrounding CK Vulpeculae. This is a star whoora was formed by a collision – an extremely rare event seen on Earth in 1670.

The research on this topic appeared in the pages of „Nature Astronomy”, and it isoThe paper’s lead author is Tomasz Kaminski of the Harvard-Smithsonian Center for Astrophysics in Cambridge. In the research team there was also another Pole – Romuald Tylenda from the Astronomical Center of im. Nicolaus Copernicus University of the Polish Academy of Sciences (CAMK PAN).

Astronomers have known about the presence of 26Al in space for decades. The compound was detected by gamma-ray observations. However, it is a compositeoł conducted by Kaminski unambiguously confirmed radioactive particles for the first time. In the remnants of the collision, astronomers found a distinct 26AI signature. Nor did previous observations reveal anything about the origin of the isotope.

When two Sun-like stars collide, the result is a spectacular explosion and the formation of an entirely new star. An event thatore led to the ejection of a radioactive particle into space was observed on Earth in 1670. Humans mow then said they saw a bright reddish spot in the sky and called it a new star.

The cosmic collision was initially clearly visible to the naked eye, but over time the light quickly faded and now powerful telescopes are neededow to see the remains of the crash. Even more so because it took place 2280 light-years from us in the constellation of Pisces.

This is the first molecule with unstable radiotworczym isotope, whichora was discovered outside the solar system. – Observing the guts of a star torn apart three centuries ago by a collision. The first observations of this isotope in a star-type object are important in the broader context of galactic chemical evolution. For the first time in sposob directly identified an active producer of the radioactive nuclide aluminum-26 – Kaminski said.

Aluminum-26 is a non-permanent variety (isotope) of aluminum. It has 13 protons in its atomic nucleusow and 13 neutronoin, which is one neutron less than in the stable isotope of aluminum-27. After radioactive decay, aluminum-26 becomes stable magnesium-26.

It is worth mentioning that aluminum-26 does not occur on Earth, so it is difficult to know its exact spectrum in laboratory experiments. Therefore, the analysis relied on laboratory measurements of a stable version of aluminum monofluoride containing aluminum-27.

During earlier detections of aluminum-26 in space outside the solar system, it was determined that it is present in the Milky Way in amounts of about twooch masses of the Sun. Unknown, however, was the process by whichory mohead to produce aluminum-26 and its origin was not very well known. The discovery that aluminum-26 was formed by the collision of dwoch stars relatively small-mass stars, as was the case with CK Vulpeculae, so it is important to explain these factsow. With the amount of aluminum-26 formed as a result of the collision in CK Vulpeculae, it is about a quarter of the mass of Pluto. And since objects of this type are rare, they are unlikely to be the only producer of aluminum-26 in the Milky Way.

This discovery is of interest to technology. It shows that millimeter-wave spectroscopy, and it was at wavelengths of this length that the aluminum-26 signature was discovered, can be a much better tool for locating the source of theodles of radioactive nuclidesow, than gamma-ray observatories.

Sourceosource: National Radio Astronomy Observatory, PAP, photo. ALMA (ESO/NAOJ/NRAO), T. Kaminski & M. Hajduk; Gemini, NOAO/AURA/NSF; NRAO/AUI/NSF, B. Saxton