A Radioactive Molecule Is Detected in Space — An Incredible First!

For the first time ever, scientists have detected a radioactive molecule in space — and it came from an ancient stellar explosion.

In the 17th century, astronomers saw a nova shining brightly in the Vulpecula constellation. But while they could see the star with the naked eye, it wasn't until 2013 that astronomers were able to tracean unusual isotopic molecular gas to the stellar event, reigniting interest in the nova. Now, in a new investigation, an international research team, led by Tomasz Kamiński from the Harvard-Smithsonian Center for Astrophysics,has shown that the nova was likely caused by the merger of two starsin what is known as a red nova. In a red nova, two stars merge in an explosive event, cool off, and then, in this "cool phase," produce large amounts of molecular gas and dust.

This team has observed this molecular gas, ²⁶AlF, a radioactive isotope of aluminum, ²⁶Al, in the remnants of the nova, known as CK Vul (or Nova Vul 1670). This is the first time that a radioactive molecule has been detected in space. This is also the first time that an object that produces ²⁶AlF has been directly identified, according to the study published today (July 30) in the journal Nature Astronomy. [Kilonova Photos: Hubble Telescope Spies Cosmic Explosion]

By observing ²⁶AlF, scientists can better understand how the merger in CK Vul happened, according to a statement. Additionally, studying the merger process shows that a stellar collision, like this red nova, can expose even the deepest layers of a star, according to the statement. In this collision, the research team has found that, in the low-mass binary system that merged, there was a red-giant-branch star with a mass between 0.8 and 2.5 solar masses.

But, while this study has shined new light on this ancient collision, it has also raised new questions. It has been known for years that there are about two solar masses of ²⁶Al across the galaxy, according to the statement. It is still unclear where this radioactive material originated, but with estimates of the mass of ²⁶AlF in CK Vul, researchers think that the merger can't be solely responsible for all of the isotope detected, according to the statement. So, the amount of the isotope found and its origin in the galaxy remain a bit of a mystery.

Still, this research has highlighted CK Vul — an object that had not before been considered as a ²⁶AlF producer. Through this work, the research team has also found that tools like the Atacama Large Millimeter/submillimeter Array (ALMA) could be more useful in searching for ²⁶Al producers than gamma-ray observatories, according to the statement. This could be useful in future investigations of the stellar remnants and ²⁶AlF in the galaxy.

Email Chelsea Gohd at cgohd@space.com or follow her @chelsea_gohd. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.