In the orbit of a distant star: researchers have discovered 30 tail stars

In the orbit of a distant star
Researchers discover 30 tail stars

April 28, 2022 at 4:50 pm

Near the star Beta Pictoris, researchers encounter dozens of exocomets. With the help of special technology they can demonstrate their size for the first time. From this, scientists have drawn similarities to the formation of our solar system.

A team of researchers from France, Brazil and the Netherlands have detected up to 30 comets near the star Beta Pictoris, 63 light-years away, using the US space telescope TESS. For the first time, astronomers were able to analyze the size distribution of the stars of another star’s tail. The outer kumites, which range in size from 3 to 14 km in size, show a distribution similar to that found in our solar system – and thus should have arisen in a similar way, The scientists write in the journal Scientific Reports..

Beta Pictoris is a young star still surrounded by a disk of gas and dust where planets may still be forming. Astronomers have discovered two large planets in the system so far – as well as traces of comets. “Comets have been observed passing in front of the star as seen from Earth for 30 years,” explain Alain Lecavallier de Etang of the Sorbonne University in France and colleagues.

Comets give themselves away because their tails of gas and dust in these transits swallow up starlight at certain wavelengths—and this absorption then appears as dark lines in the beta-pictorial spectrum. Scientists now used a different method of observing: Using NASA’s TESS (Transiting Exoplanet Survey Satellite) telescope, they monitored the star’s brightness with high accuracy for 156 days.

Brightness allows inferences about volume to be drawn

TESS is used to search for planets close to other stars: if such a planet passes in front of the star as seen from Earth, it dims the star’s light slightly and thus reveals itself. The transit of a comet with its large tail also results in such attenuation – albeit less. The researchers were able to identify a total of 30 transiting comets in the TESS data. Based on the strength of the weakness, they were also able to deduce the size of the comet.

This made it possible for the first time to determine the size distribution of comets near another star. The scientists stated that “16 comets are three to four kilometers in diameter – but only four are between six and eight kilometers in diameter and only one is between eight and ten kilometers.” Therefore small comets are more common in Beta Pictoris than large comets. So the distribution is similar to the distribution in our solar system.

For the researchers, this is an indication that the formation and evolution of comets in Beta Pictoris was similar to that in our planetary system. Such a distribution of sizes occurs when celestial bodies collide with each other and disintegrate – but sometimes they merge again to form larger ones. This is an important finding for astronomers, because comets may have brought a significant portion of the water to the inner solar system and thus to Earth as well. Therefore such processes should also take place in other planetary systems in a very similar way.