'Fluorine' in toothpastes was produced in stars billions of years ago

A new study has claimed that fluorine, which is found in everyday products such as toothpaste and chewing gum, was formed in stars billions of years ago.

Astronomers from Lund University in Sweden with colleagues from Ireland and the USA, have presented findings that say that the chemical element was created in stars similar to the sun but heavier, towards the end of their existence. The sun and the planets in our solar system have then been formed out of material from these dead stars.

The scientists studied stars formed at different points in the history of the universe to see if the amount of fluorine they contain agreed with the predictions of the theory.

By analysing the light emitted by a star, it is possible to calculate how much of different elements it contained. Light of a certain wavelength indicates a certain element. The researchers used a telescope on Hawaii and a new type of instrument that's sensitive to light with a wavelength in the middle of the infrared spectrum. It is in this area that the signal is found in this case.

Different chemical elements were formed at high pressure and temperature inside a star. Fluorine was formed towards the end of the star's life, when it has expanded to become what is known as a red giant. The fluorine then moved to the outer parts of the star, which then casted off the outer parts and formed a planetary nebula. The fluorine that was thrown out in this process mixed with the gas that surrounded the stars, known as the interstellar medium.

New stars and planets were then formed from the interstellar medium. When the new stars died, the interstellar medium was enriched once again.