December 12, 2015
Massive Jupiter-like storm discovered on tiny brown dwarf star
Using NASA’s Kepler and Spitzer space telescopes, a team of astronomers discovered an unusual brown dwarf star that is nearly as big as Jupiter and has a large, persistent storm similar to that planet’s Great Red Spot, officials at the US space agency announced Thursday.
The brown dwarf in question is known as W1906+40, and according to USA Today, it is nearly 53 light years (or more than 300 trillion miles) from Earth. The storm continued for at least two years and provides the best evidence yet for a star with this type of activity, John Gizis from the University of Delaware, Newark and his colleagues wrote in The Astrophysical Journal.W1906+40 belongs to a class of objects known as L-dwarfs, which Popular Mechanics explains are at the crossroads between small, cool stars and those known as brown dwarfs, which failed to reach temperatures hot enough to fuse atoms into new elements. At 3,500 degrees Fahrenheit, it is hot enough to be considered a star, but cool enough to form clouds in its atmosphere.
This marks the first time that this type of weather phenomenon has been directly observed on an L-dwarf star, although some weather patterns were previously spotted around brown dwarfs, according to NASA. Astronomers believe that the storm clouds and their precipitation are made out of molten iron, hot sand or salts, and that its lightning is likely more violent than storms found on Jupiter.
Researchers now plan to see how common these storms are
Gizis and his fellow researchers monitored atmospheric changes in W1906+40 for more than 24 months. The L-dwarf, which was originally detected in 2011 with the Wide-field Infrared Survey Explorer (WISE), was later found to be located in the same region of the sky after being analyzed by NASA’s planet-hunting Kepler mission.
Typically, Kepler seeks out new worlds by looking for dips in starlight occurring when a planet passes in front of its star. However, in this instance, the study authors found flickers that clearly were not coming from planets. Initially, they thought that a star spot could have been the cause, but follow-up observations conducted using the Spitzer telescope proved otherwise.
Star spots are the result of concentrated magnetic fields, but Spitzer found that the object was not magnetic in nature, but was instead a massive, cloudy storm with a diameter they said would be large enough to hold three Earths. The storm orbits its star once every nine hours.
Gizis and his colleagues said that they now plan to hunt for other, similar features on other stars and brown dwarfs using Kepler and Spitzer. “We don't know if this kind of star storm is unique or common,” he said in a statement Thursday, “and we don't why it persists for so long.”
An artist's concept of the storm in question. Image credit: NASA JPL