Auroras across the universe

We all love the Northern Lights. Google that and any number of photos like the one below will pop up … some red, some green, some a mixture of colors – but all beautifully fascinating.

Turns out, we aren’t the only ones to have them.

Space.com did a really good job of describing how auroras are formed on Earth in the article below, and then describes how scientists were surprised to see the same effect on a brown dwarf that’s over 18 light years away from Earth.

New discoveries are always exciting, but trying to explain what we have just observed is even more fun.

And that’s why we think this article is a good read!

First Alien Auroras Found, Are 1 Million Times Brighter Than Any On Earth

by Charles Q. Choi, Space.com Contributor   |   July 29, 2015 01:01pm ET

Astronomers have discovered the first auroras ever seen outside the solar system — alien light shows more powerful than any other auroras ever witnessed, perhaps 1 million times brighter than any on Earth, researchers say.

Auroras could soon be detected from distant exoplanets as well, investigators added.

Auroras, the radiant displays of colors in the sky known on Earth as the northern or southern lights, are also seen on all of the other planets with magnetic fields in the solar system. They are caused by currents in the magnetosphere of a planet — the shell of electrically charged particles captured by a planet’s magnetic field — that force electrons to rain down on the atmosphere, colliding with the molecules within and making them give off light. [Amazing Auroras on Earth in 2015 (Photos)]

To see if auroras might be seen outside the solar system, astronomers investigated a mysterious Jupiter-size object called LSR J1835+3259, located about 18.5 light-years from Earth. The object is a few dozen times more massive than Jupiter, suggesting it is too heavy to be a planet but too light to be a star, the researchers said.

They suggested that LSR J1835+3259 is a brown dwarf, a strange misfit object sometimes known as a failed star. As massive as brown dwarfs are compared to planets, they are too puny to force atoms to fuse together and release the nuclear energy that powers stars.

…… “If you were to somehow stand on the brown dwarf’s surface and survive — the surface gravity is maybe 100 times more intense than Earth’s, and the temperature is several hundred to several thousand degrees — you’d see a beautiful bright-red aurora,” Hallinan said. “The colors of auroras depend on whatever the atmosphere they take place in is made of. In Earth’s case, it’s mostly green and blue and red because of oxygen and nitrogen. When it comes to Jupiter, Saturn and brown dwarfs — which have hydrogen-rich atmospheres — you’d see red, and there would be ultraviolet and infrared wavelengths as well.”

Until now, the brightest known auroras came from Jupiter, which has the most powerful magnetic field in the solar system. In comparison, these newfound auroras are more than 10,000 times — and maybe 100,000 times — brighter than Jupiter’s, Hallinan said. This is because LSR J1835+3259 has a magnetic field perhaps 200 times stronger than Jupiter’s, he said.

It remains a mystery what might drive LSR J1835+3259’s auroras. On Earth, auroras are driven by winds of electrically charged particles streaming from the sun, but this brown dwarf does not have a stellar companion.

…… For the full article, please visit Space.com

Cover photo: Auroras detected on the brown dwarf LSR J1835+3259 are much brighter than auroras on Earth, possibly 1 million times brighter than the best northern lights we can see, scientists say.  Credit: Chuck Carter and Gregg Hallinan/Caltech