Bizarre, rogue planet boasts impressive magnetic aurora

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The planet is only around 20 light years from Earth, but it's not really doing much besides relaxing in the vastness of space.

At 200 million years old and approximately 20 light-years from Earth, SIMP0136 has a surface temperature of about 1,500 degrees Fahrenheit (825 degrees Celsius). Brown dwarf planets are sometimes called "failed stars" because they're almost large enough for fusion to begin taking place in their core, but that's not even the most unique thing about this particular planet. Hoverer, the new object generates a magnetic field 200 times a powerful as Jupiter's.

The new discovery, made with the National Science Foundation's Karl G. Jansky Very Large Array telescopes in New Mexico, marks the first radio observations of a planetary-mass object beyond our solar system. Scientists aren't exactly sure how the auroras form in brown dwarfs, but they do have some theories.


When this object was discovered in 2016 along with four brown dwarfs, scientists believed that it was older and more massive.

"This particular object is exciting because studying its magnetic dynamo mechanisms can give us new insights on how the same type of mechanisms can operate in extrasolar planets - planets beyond our solar system".

SIMP's magnetic field is over 200 times that of Jupiter's, notes the report. The auroras on Earth are caused by our planet's magnetic field interacting with the solar wind. But it's possible an orbiting planet or moon could trigger similar interactions like the ones seen between Jupiter and its moon Io.


Brown dwarf masses are notoriously hard to measure, and at the time, SIMP0136 was thought to be an old and much more massive brown dwarf. One rule of thumb in drawing the distinction is the mass below which fusion of deuterium is not possible - about 13 Jupiter masses.

The difference between what constitutes gas giants and brown dwarfs is a matter of serious debate among astronomers, says NRAO.

"[This presents] huge challenges to our understanding of the dynamo mechanism that produces the magnetic fields in brown dwarfs and exoplanets and helps drive the auroras we see", said Gregg Hallinan, study co-author and assistant professor of astronomy at the California Institute of Astronomy, in a statement.


The planet is considered to be a rogue one because it does not have an orbit around a parent star, unlike the planets of the solar system.

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