ESO Science Release | 2018 Jul 30
Observations using ALMA find radioactive isotope aluminium-26 from the remnant CK Vulpeculae
Astronomers using ALMA and NOEMA have made the first definitive detection of a radioactive molecule in interstellar space. The radioactive part of the molecule is an isotope of aluminium. The observations reveal that the isotope was dispersed into space after the collision of two stars, that left behind a remnant known as CK Vulpeculae. This is the first time that a direct observation has been made of this element from a known source. Previous identifications of this isotope have come from the detection of gamma rays, but their precise origin had been unknown.
The team, led by Tomasz Kamiński (Harvard-Smithsonian Center for Astrophysics, Cambridge, USA), used the Atacama Large Millimeter/submillimeter Array (ALMA) and the NOrthern Extended Millimeter Array (NOEMA) to detect a source of the radioactive isotope aluminium-26. The source, known as CK Vulpeculae, was first seen in 1670 and at the time it appeared to observers as a bright, red “new star”. Though initially visible with the naked eye, it quickly faded and now requires powerful telescopes to see the remains of this merger, a dim central star surrounded by a halo of glowing material flowing away from it.
348 years after the initial event was observed, the remains of this explosive stellar merger have led to the clear and convincing signature of a radioactive version of aluminum, known as aluminium-26. This is the first unstable radioactive molecule definitively detected outside of the Solar System. Unstable isotopes have an excess of nuclear energy and eventually decay into a stable form. ...
Pair of Colliding Stars Spill Radioactive Molecules into Space
ALMA | NRAO | ESO | NAOJ | 2018 Jul 30
26AlF -- First Detection of a Radioactive Molecule in Space
Max Planck Institute for Radio Astronomy | 2018 Jul 30
Astronomical Detection of a Radioactive Molecule 26AlF in a Remnant of an Ancient Explosion - Tomasz Kamiński et al
- Nature Astronomy (online 30 Jul 2018) DOI: 10.1038/s41550-018-0541-x
arXiv.org > astro-ph > arXiv:1807.10647 > 27 Jul 2018