Mass of tiny binary star discovered, thanks to its intense radio emissions

Researchers have discovered intense radio emission from a tiny binary star, which calls for a review of stellar models.

As per the University of Valencia study, this small binary star is known as AB Doradus B and is located in the AB Doradus star system, consisting of two pairs of stars. Stars normally emit light that can be seen with the naked eye or through telescopes, but some also emit radio waves, similar to those from televisions, mobile phones or microwave ovens.

Co-author Jose Carlos Guirado said that these emissions have made it possible to calculate the mass of the star, which is usually complex, but when the star is accompanied by another, its orbital motion gives us an accurate way to determine it, as Kepler's laws establish.

He added that the mass of these stars cannot be reproduced by the current models of stellar evolution, so we require a major overhaul of these theories.

The study of the pair Ba and Bb has revealed that these stars, as pointed out by co-author Rebecca Azulay, have an intense radio emission that has been captured by the Australian interferometer antennas, but the stars shine at visible wavelengths and not so much at radio wavelengths. The question is where do such emissions come from?

Azulay added that the high speed of rotation of each of the stars makes them suspect that both Ba and Bb are, in turn, the result of two stars in contact at very high rotation rates which merged into a single object. That is why, still today, Ba and Bb revolve on themselves at great speed and produce intense radio waves in the same way that a bicycle dynamo generates light when the wheels turn.

The study is published in the journal Astronomy & Astrophysics.