The Stellar Origins of Our Toothpaste: Fluorine Created by Red Giants

Most people know that fluorine can be found in our toothpaste, but did you know about its stellar origins? Scientists have found that fluorine was probably formed billions of years ago in now dead stars of the same type as our own sun.

Fluorine can be found in products that range from toothpaste to fluorine chewing gum. Yet the origins of this chemical element have been somewhat of a mystery; scientists mostly relied on three different theories as to how it was created. Now, though, researchers have discovered new evidence that supports the theory that fluorine is formed in stars similar to the sun but heavier.

"So, the fluorine in our toothpaste originates from the sun's dead ancestors," said Nils Ryde, one of the researchers, in a news release.

In order to learn a bit more about the origins of fluorine, the researchers studied stars formed at different points in the history of the universe. This allowed them to see if the amount of fluorine the stars contained agreed with predictions in the theory they were testing. The scientists analyzed the light emitted by stars in order to calculate how much of different elements they contained.

In the end, the researchers found that fluorine is formed toward the end of a star's life, when it has expanded to become what is known as a red giant. Then, the fluorine moves to the outer parts of the star where it is eventually cast off when the star becomes a planetary nebula. The fluorine then mixes with the gas that surrounds the stars, known as the interstellar medium; this material is then used to create new stars and planets.

Currently, the researchers are planning to study other types of stars to see if fluorine could have been produced in the early universe, before the first red giants formed. This could tell them a bit more about the evolution of the universe as a whole, and show them how fluorine came to enter our galaxy.