Science. The give and take of stellar flares and their effect on the planets
Madrid, 17 (European Press)
Long-term relationships between stars and the planets around them, including the Sun and Earth, can be more complex than previously thought.
That’s one of the conclusions of a new study of thousands of stars using NASA’s Chandra X-ray Observatory.
By conducting the largest-ever study of star-forming regions in X-rays, a team of researchers has helped determine the link between very powerful flares or explosions from young stars and the effect they can have on the planets that orbit them.
“Our work tells us how the Sun behaved and affected the young Earth billions of years ago,” Konstantin Guttmann of Penn State University in University Park, Pennsylvania, who led the study, said in a statement. “In a way, this is our last origin story – how the Earth and the solar system came into being.”
Scientists examined Chandra X-ray data from more than 24,000 stars in 40 different regions where stars are forming. They captured more than a thousand stars that emit flares that are much more energetic than the strongest glow observed by modern astronomers on the Sun, the “Carrington Solar Event” in 1859. The “super” flares were at least a hundred thousand times more frequent. more powerful. From the Carrington event, the “mega” ignites with a force of up to 10 million times.
The flares that Chandra observed in this work occur in all regions of star formation and between young stars of all different masses, including those similar to the Sun, as seen in all the different stages of the evolution of young stars, ranging from the earliest stages when the star is densely covered with dust. and gas and surrounded by a large planet-forming disk, to the later stages in which the planets formed and the disks disappeared. The stars in the study are estimated to be less than 5 million years old, compared to the Sun’s age of 4.5 billion years.
The team found that several superflares occur per week per young star, an average of over the entire sample, and about two massive flares per year.
“We want to know what kind of effect, good and bad, these eruptions had on the life of the first planets,” said co-author Eric Fegelson, of Penn State University. “Such strong flares could have important ramifications.”
Over the past two decades, scientists have argued that these giant flares could help “give” planets to form stars by pulling gas away from the disks of surrounding material. This can lead to the formation of pebbles and other small rock materials and is a critical step for planet formation.
On the other hand, these flares can “remove” planets that have already formed by bombarding any atmosphere with powerful radiation, which could evaporate and completely destroy them in less than 5 million years.
The researchers also detailed models of 55 very bright and ultra-bright flares and found that most of them resemble the long-duration flares seen in the Sun that produce “coronal mass ejections,” powerful ejections of charged particles that can damage planetary atmospheres. The Carrington Solar event included such a package.
This work is also important in understanding the eruptions themselves. The team found that the properties of the flares, such as their brightness and frequency, are the same as for young stars that do not have planet-forming disks. This indicates that the flares are likely similar to those seen on the Sun, with the rings of the magnetic field having footprints on the surface of the star, rather than one fixed to the disk and one to the star.
“We found that these giant flares are similar to those in the Sun, but are greatly amplified in terms of energy and frequency, and in the size of their magnetic rings,” said co-author Gordon Garmire of the Huntingdon Institute of X-ray Astronomy in India. Huntingdon, Pennsylvania. “Understanding these starbursts can help us understand the most powerful flares and coronal mass ejections from the Sun.”