Colliding magnetic fields reveal unknown planets

Ph.D. candidate astronomer Rob Kavanagh has developed mathematical fashions to higher perceive the interactions between exoplanets and stellar winds and to outline options of exoplanets.

Exoplanets are planets that orbit round different stars than the sun. They’re typically tough to detect, however now it seems that interactions between exoplanets and stellar winds produce alerts that radio telescopes can detect. Stellar winds are sizzling streams of charged particles that constantly escape from the surfaces of stars such because the sun.

“When stellar winds collide with the magnetic fields of orbiting planets, the interplay can produce a vibrant emission. On the Earth, we will see such emission because the northern lights,” says Kavanagh.

Modeling stellar winds

Final 12 months, hints of such interactions occurring in different stellar methods had been detected with the radio telescope LOFAR (Low-Frequency Array) for the primary time. “Round twenty dwarf stars had been discovered that emit radio emission. This might be because of exoplanets orbiting round these stars, though they don’t seem to be at present recognized to host any planets,” says Kavanagh. In mathematical fashions he simulates stellar wind environments. That method, Kavanagh hopes to higher perceive the alerts which can be generated by the interplay between exoplanets and stellar winds.

“Kavanagh’s analysis additionally helps to interpret LOFAR’s new observations,” says his supervisor Aline Vidotto of the Leiden Observatory.

Exploring exoplanets

Kavanagh’s fashions usually are not solely helpful for detecting new exoplanets. Radio emission additionally gives all types of details about, for instance, the scale of the planet and its orbit round its parent star. Kavanagh mentioned, “Trying on the planets inside our personal solar system, we count on that enormous planets, orbiting near their mother or father star, will produce the strongest radio alerts.”

As well as, the power of the emission may also reveal one thing in regards to the properties of the stellar winds themselves and the scale of the magnetic area round an exoplanet. “Vital info, as a result of it’s seemingly that the Earth’s magnetic area has ensured that we now have an environment,” Kavanagh said. The presence and measurement of a magnetic field due to this fact gives astronomers with a sign of the habitability of a planet. “And that turns out to be useful within the seek for extraterrestrial life.”

On to ASTRON

Kavanagh is now working as a postdoc at ASTRON, the Netherlands Institute for Radio Astronomy. “Right here I’ll proceed to develop fashions and I will even begin wanting into brown dwarf stars. These stars emit an enormous quantity of radio emission, which is puzzling. The extra I give it some thought, the stranger I discover it,” Kavanagh laughs.

In the meantime, Vidotto is comfortable that Kavanagh is staying within the Netherlands, wanting ahead to future collaborations. “We began our analysis collectively in Eire, however midway via Kavanagh’s Ph.D., I moved to Leiden to make it simpler to collaborate with my colleague-astronomers,” says Vidotto. After some doubt, Kavanagh joined his supervisor. “It was an enormous problem to immediately to migrate in the course of a pandemic, however I am glad I did.”