Thanks to the Cheops satellite, scientists have been able to study the planet HIP 67522 b, which orbits very close to a young star. They discovered that it was practically causing its own demise by provoking flares on its surface.
Star HIP 67522 b
Scientists have discovered that the planet HIP 67522b is trying to kill itself. That was all thanks to the Cheops space telescope, which the European Space Agency launched into orbit back in 2019. It had watched this world and its star long enough to learn all their secrets.
The star HIP 67522 is interesting because it is similar to the Sun, only slightly heavier and colder. It is also much younger than our star. It is not 4.5 billion years old, but only 17 million years old. It has two planets, the closer of which, the one observed by astronomers, completes one orbit in only seven days.
And it was this feature that caught the attention of astronomers. The fact is that virtually every star in the main sequence occasionally experiences flares caused by disturbances in its magnetic field. At the same time, the Sun, which we often complain about, still has a relatively calm magnetic field and a small number of flares. HIP 67522 should have many more of them.
Planet and magnetic field
In general, since the discovery of the first exoplanets, scientists have been interested in how the presence of one of them in a sufficiently close orbit will affect the magnetic field of a star. After all, they have their own field, and if it is powerful enough, they can easily disrupt the processes occurring on the Sun and increase the frequency of flares.
This is precisely why scientists are so interested in HIP 67522. It is as heavy as Jupiter and is located close to its young star. And research using Cheops shows that flares at dawn really occur 100 times more often than expected.
Suicide
Being bombarded with such a large amount of high-energy radiation does not promise anything good for HIP 67522 b. The planet is similar in size to Jupiter, but has the density of cotton candy, making it one of the lightest exoplanets ever found.
Over time, radiation destroys the planet’s fluffy atmosphere, which means that it loses mass much faster than expected. Over the next 100 million years, it could transform from a planet nearly the size of Jupiter into a much smaller planet, about the size of Neptune.
“The planet seems to be triggering particularly energetic flares,” notes Ekaterina Ilin. “The waves it sends along the star’s magnetic field lines kick off flares at specific moments. But the energy of the flares is much higher than the energy of the waves. We think that the waves are setting off explosions that are waiting to happen.”
More questions than answers
When HIP 67522 was discovered, it was the youngest known planet orbiting so close to its star. Since then, astronomers have discovered several more similar systems, and there are probably dozens more in the nearby Universe. Ekaterina and her team aim to explore these unique systems in greater detail using TESS, Cheops, and other exoplanet-hunting missions.
Scientists believe that this is a completely new phenomenon, and its details have not yet been fully clarified. In their opinion, the most important thing to do now is two things. The first is to conduct further observations in various wave ranges to determine what kind of energy is released during these flares — for example, ultraviolet and X-ray radiation are particularly harmful to exoplanets.
The second is to search for and study other similar systems of stars and planets; by moving from a single case to a group of 10–100 systems, astronomers will obtain material for their work.
According to www.esa.int
