Northern Lights is also found outside solar system – NU.nl

The auroras were observed in the atmospheres of several “failed stars” known as brown dwarfs.

The results were Thursday presented in Nature by an international team of scientists .

“This is the first time that auroras are seen on brown dwarfs,” says lead author Professor Greg Hallinan of the California Institute of Technology.

According to the scientists, the discovery is a sign that brown dwarfs are more like planets than previously thought.

Brown dwarfs are not massive enough to reach the core temperatures and pressures necessary for nuclear fusion, the process that causes stars like our sun light and radiate heat.

This means that a brown dwarf is a cross between a small star, a red dwarf and a giant gas planet like Jupiter.

Northern Light

Polar Lights often occur around the high latitudes on Earth and are called Northern Lights. On all planets with magnetic fields come auroras for.

The phenomenon is caused when charged particles in the solar wind interact with the magnetosphere of a planet.

The particles flutter down along the magnetic field lines, and collide with atoms in the atmosphere, with a spectacular (optical) light show as a result. The phenomenon also emits radio waves.

The scientists sensed the optical and radio signals at a rapidly rotating brown dwarf called LSR J1835, which is located about 18 light years from our planet is in the Lyran system.

“When radio waves from the brown dwarf saw come, we speculated that the object had aurora,” Hallinan said.

Later found similar signals at smaller and cooler brown dwarfs. Hallinan: “That tells us that brown dwarfs behave more like massive planets, a kind of giant Jupiters, then like little stars.”

Red light

The aurora on the brown dwarf is predominantly red in color, because the charged particles in the atmosphere, especially react with hydrogen molecules in the atmosphere. On Earth they mostly react with oxygen molecules, resulting in a green color.

How the auroras on the brown dwarfs occurs is still unclear. The failed stars are not close to a star like our sun, which they can bombard with charged particles.

According to astronomers, it is possible that the dwarf himself those particles, electrons, produced by material from the planet’s surface is stripped . Another theory is that an undiscovered planet or moon around the dwarf who hurls matter in space.

The aurora in the star is thousands of times as strong as that of Jupiter, and is on turn a thousand times as strong as the auroras on Earth

By:. ANP / NU.nl