\n\t\t\t\t\t\t\t\tNASA\u2019s Webb Finds Signs of Possible Aurorae on Isolated Brown Dwarf\t\t\t\t\t\t\t<\/h1>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n<\/div>\n![\"An](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/01\/webb-stsci-01hkmvcm2zq9xgy7vfgap0c3na.png?w=1536\")
<\/figure>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n\n\n\nArtist’s concept portrays the brown dwarf W1935.<\/figcaption><\/div>\n<\/p><\/div>\n\n\t\t\t\t\t\tCredits: <\/span>
\n\t\t\t\t\t\tNASA, ESA, CSA, and L. Hustak (STScI)<\/span>\n\t\t\t\t\t<\/div>\n<\/figcaption><\/div>\n<\/p><\/div>\n<\/p><\/div>\nInfrared emission from methane suggests atmospheric heating by auroral processes.<\/em><\/strong><\/p>\nAstronomers using NASA\u2019s James Webb Space Telescope have found a brown dwarf<\/a> (an object more massive than Jupiter but smaller than a star) with infrared emission<\/a> from methane, likely due to energy in its upper atmosphere. This is an unexpected discovery because the brown dwarf, W1935, is cold and lacks a host star; therefore, there is no obvious source for the upper atmosphere energy. The team speculates that the methane emission may be due to processes generating aurorae.<\/p>\nThese findings are being presented at the 243rd<\/sup> meeting of the American Astronomical Society in New Orleans.<\/p>\nTo help explain the mystery of the infrared emission from methane, the team turned to our solar system.\u00a0Methane in emission is a common feature in gas giants like Jupiter and Saturn. The upper-atmosphere heating that powers this emission is linked to aurorae.<\/p>\n
Image: Artist Concept Brown Dwarf W1935<\/h2>\n\n\n\n![\"An](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/01\/webb-stsci-01hkmvbkcj8fxr63h112y044pw-4k.png?w=2048\")
<\/figure>\nThis artist concept portrays the brown dwarf W1935, which is located 47 light-years from Earth. Astronomers using NASA\u2019s James Webb Space Telescope found infrared emission from methane coming from W1935. This is an unexpected discovery because the brown dwarf is cold and lacks a host star; therefore, there is no obvious source of energy to heat its upper atmosphere and make the methane glow. The team speculates that the methane emission may be due to processes generating aurorae, shown here in red.<\/div>\nNASA, ESA, CSA, and L. Hustak (STScI)<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nOn Earth, aurorae are created when energetic particles blown into space from the Sun are captured by Earth\u2019s magnetic field. They cascade down into our atmosphere along magnetic field lines near Earth\u2019s poles, colliding with gas molecules and creating eerie, dancing curtains of light. Jupiter and Saturn have similar auroral processes that involve interacting with the solar wind, but they also get auroral contributions from nearby active moons like Io (for Jupiter) and Enceladus (for Saturn).<\/p>\n
For isolated brown dwarfs like W1935, the absence of a stellar wind to contribute to the auroral process and explain the extra energy in the upper atmosphere required for the methane emission is a mystery.\u00a0The team surmises that either unaccounted internal processes like the atmospheric phenomena of Jupiter and Saturn, or external interactions with either interstellar plasma or a nearby active moon, may help account for the emission.<\/p>\n
A Detective Story<\/h2>\n
The aurorae\u2019s discovery played out like a detective story. A team led by Jackie Faherty, an astronomer at the American Museum of Natural History in New York, was awarded time with the Webb telescope to investigate 12 cold brown dwarfs.\u00a0Among those were W1935 \u2013 an object that was discovered by citizen scientist Dan Caselden, who worked with the Backyard Worlds zooniverse project \u2013 and W2220, an object that was discovered using NASA\u2019s Wide Field Infrared Survey Explorer. Webb revealed in exquisite detail that W1935 and W2220 appeared to be near clones of each other in composition. They also shared similar brightness, temperatures, and spectral features<\/a> of water, ammonia, carbon monoxide, and carbon dioxide. The striking exception was that W1935 showed emission from methane, as opposed to the anticipated absorption feature that was observed toward W2220.\u00a0This was seen at a distinct infrared wavelength to which Webb is uniquely sensitive.<\/p>\n\u201cWe expected to see methane because methane is all over these brown dwarfs. But instead of absorbing light, we saw just the opposite: The methane was glowing.\u00a0My first thought was, what the heck? Why is methane emission coming out of this object?\u201d said Faherty.<\/p>\n
The team used computer models to infer what might be behind the emission. The modeling work showed that W2220 had an expected distribution of energy throughout the atmosphere, getting cooler with increasing altitude. W1935, on the other hand, had a surprising result.\u00a0The best model favored a temperature inversion, where the atmosphere got warmer with increasing altitude.\u00a0 \u201cThis temperature inversion is really puzzling,\u201d said Ben Burningham, a co-author from the University of Hertfordshire in England and lead modeler on the work. \u201cWe have seen this kind of phenomenon in planets with a nearby star that can heat the stratosphere, but seeing it in an object with no obvious external heat source is wild.\u201d\u00a0\u00a0<\/p>\n
Image: Spectra W1935 vs W2220<\/h2>\n\n\n\n![\"A](\"https:\/\/www.nasa.gov\/wp-content\/uploads\/2024\/01\/webb-stsci-01hkmvqc58zs5ftmb6p20pq8h4.png?w=1920\")
<\/figure>\nAstronomers used NASA\u2019s James Webb Space Telescope to study 12 cold brown dwarfs. Two of them \u2013 W1935 and W2220 \u2013 appeared to be near twins of each other in composition, brightness, and temperature. However, W1935 showed emission from methane, as opposed to the anticipated absorption feature that was observed toward W2220. The team speculates that the methane emission may be due to processes generating aurorae.<\/div>\nNASA, ESA, CSA, and L. Hustak (STScI)<\/div>\n<\/figcaption><\/div>\n<\/div>\n<\/div>\nClues from our Solar System<\/h2>\n
For clues, the team looked in our own backyard, to the planets of our solar system.\u00a0The gas giant planets can serve as proxies for what is seen going on more than 40 light-years away in the atmosphere of W1935.<\/p>\n
The team realized that temperature inversions are prominent in planets like Jupiter and Saturn. There is still ongoing work to understand the causes of their stratospheric heating, but leading theories for the solar system involve external heating by aurorae and internal energy transport from deeper in the atmosphere (with the former a leading explanation).<\/p>\n
Brown Dwarf Aurora Candidates in Context<\/h2>\n
This is not the first time an aurora has been used to explain a brown dwarf observation.\u00a0Astronomers have detected radio emission coming from several warmer brown dwarfs and invoked aurorae as the most likely explanation. Searches were conducted with ground-based telescopes like the Keck Observatory for infrared signatures from these radio-emitting brown dwarfs to further characterize the phenomenon, but were inconclusive.<\/p>\n
W1935 is the first auroral candidate outside the solar system with the signature of methane emission. It\u2019s also the coldest auroral candidate outside our solar system, with an effective temperature of about 400 degrees Fahrenheit (200 degrees Celsius), about 600 degrees Fahrenheit warmer than Jupiter.<\/p>\n
In our solar system the solar wind is a primary contributor to auroral processes, with active moons like Io and Enceladus playing a role for planets like Jupiter and Saturn, respectively. W1935 lacks a companion star entirely, so a stellar wind cannot contribute to the phenomenon.\u00a0It is yet to be seen whether an active moon might play a role in the methane emission on W1935.\u00a0<\/p>\n
\u201cWith W1935, we now have a spectacular extension of a solar system phenomenon without any stellar irradiation to help in the explanation.\u201d Faherty noted. \u201cWith Webb, we can really \u2018open the hood\u2019 on the chemistry and unpack how similar or different the auroral process may be beyond our solar system,\u201d she added.<\/p>\n
The James Webb Space Telescope is the world\u2019s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.<\/em><\/p>\nWant to help discover a new world? <\/h2>\n
Want to help discover a new world? Join the\u00a0Backyard Worlds: Planet 9<\/a>\u00a0citizen science project and search the realm beyond Neptune for new brown dwarfs and planets. Or try NASA\u2019s new\u00a0Burst Chaser<\/a>\u00a0citizen science project, which launched Jan. 9.<\/p>\nDownloads<\/h2>\n
Download full resolution images for this article<\/a><\/strong> from the Space Telescope Science Institute.<\/p>\nRight click the images in this article to open a larger version in a new tab\/window.<\/p>\n
Media Contacts<\/h2>\n
Laura\u00a0Betz<\/strong> \u2013 laura.e.betz@nasa.gov<\/a>, Rob Gutro<\/strong>\u2013 rob.gutro@nasa.gov<\/a>
NASA\u2019s \u00a0Goddard Space Flight Center<\/em><\/a>,\u00a0<\/em>, Greenbelt, Md.<\/p>\nChristine Pulliam<\/strong> \u2013 cpulliam@stsci.ed<\/a>u
Space Telescope Science Institute<\/a>, Baltimore, Md.<\/p>\nRelated Information<\/h2>\n
Brown Dwarfs<\/strong><\/a><\/p>\nMore Webb News<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/latestnews\/<\/p>\nMore Webb Images<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/multimedia\/images\/<\/p>\nWebb Mission Page<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/<\/p>\n<\/p>\nRelated For Kids<\/h2>\n
What is the Webb Telescope?<\/strong><\/a><\/p>\nSpacePlace for Kids<\/strong><\/a><\/p>\nEn Espa\u00f1ol<\/h2>\n
Ciencia de la NASA<\/strong><\/a><\/p>\nNASA en espa\u00f1ol\u00a0<\/strong><\/a><\/p>\nSpace Place\u00a0para ni\u00f1os<\/strong><\/a><\/p>\n\n\n\n\nKeep Exploring<\/div>\nRelated Topics<\/h2>\n<\/p><\/div>\n<\/p><\/div>\n\n\t\t\t\t\t<\/p>\n\n
<\/figure>\n<\/p><\/div>\n<\/p><\/div>\n<\/p><\/div>\n\n\t\t\t\t\t\tNASA, ESA, CSA, and L. Hustak (STScI)<\/span>\n\t\t\t\t\t<\/div>\n<\/figcaption><\/div>\n<\/p><\/div>\n<\/p><\/div>\n
Infrared emission from methane suggests atmospheric heating by auroral processes.<\/em><\/strong><\/p>\n Astronomers using NASA\u2019s James Webb Space Telescope have found a brown dwarf<\/a> (an object more massive than Jupiter but smaller than a star) with infrared emission<\/a> from methane, likely due to energy in its upper atmosphere. This is an unexpected discovery because the brown dwarf, W1935, is cold and lacks a host star; therefore, there is no obvious source for the upper atmosphere energy. The team speculates that the methane emission may be due to processes generating aurorae.<\/p>\n These findings are being presented at the 243rd<\/sup> meeting of the American Astronomical Society in New Orleans.<\/p>\n To help explain the mystery of the infrared emission from methane, the team turned to our solar system.\u00a0Methane in emission is a common feature in gas giants like Jupiter and Saturn. The upper-atmosphere heating that powers this emission is linked to aurorae.<\/p>\n On Earth, aurorae are created when energetic particles blown into space from the Sun are captured by Earth\u2019s magnetic field. They cascade down into our atmosphere along magnetic field lines near Earth\u2019s poles, colliding with gas molecules and creating eerie, dancing curtains of light. Jupiter and Saturn have similar auroral processes that involve interacting with the solar wind, but they also get auroral contributions from nearby active moons like Io (for Jupiter) and Enceladus (for Saturn).<\/p>\n For isolated brown dwarfs like W1935, the absence of a stellar wind to contribute to the auroral process and explain the extra energy in the upper atmosphere required for the methane emission is a mystery.\u00a0The team surmises that either unaccounted internal processes like the atmospheric phenomena of Jupiter and Saturn, or external interactions with either interstellar plasma or a nearby active moon, may help account for the emission.<\/p>\n The aurorae\u2019s discovery played out like a detective story. A team led by Jackie Faherty, an astronomer at the American Museum of Natural History in New York, was awarded time with the Webb telescope to investigate 12 cold brown dwarfs.\u00a0Among those were W1935 \u2013 an object that was discovered by citizen scientist Dan Caselden, who worked with the Backyard Worlds zooniverse project \u2013 and W2220, an object that was discovered using NASA\u2019s Wide Field Infrared Survey Explorer. Webb revealed in exquisite detail that W1935 and W2220 appeared to be near clones of each other in composition. They also shared similar brightness, temperatures, and spectral features<\/a> of water, ammonia, carbon monoxide, and carbon dioxide. The striking exception was that W1935 showed emission from methane, as opposed to the anticipated absorption feature that was observed toward W2220.\u00a0This was seen at a distinct infrared wavelength to which Webb is uniquely sensitive.<\/p>\n \u201cWe expected to see methane because methane is all over these brown dwarfs. But instead of absorbing light, we saw just the opposite: The methane was glowing.\u00a0My first thought was, what the heck? Why is methane emission coming out of this object?\u201d said Faherty.<\/p>\n The team used computer models to infer what might be behind the emission. The modeling work showed that W2220 had an expected distribution of energy throughout the atmosphere, getting cooler with increasing altitude. W1935, on the other hand, had a surprising result.\u00a0The best model favored a temperature inversion, where the atmosphere got warmer with increasing altitude.\u00a0 \u201cThis temperature inversion is really puzzling,\u201d said Ben Burningham, a co-author from the University of Hertfordshire in England and lead modeler on the work. \u201cWe have seen this kind of phenomenon in planets with a nearby star that can heat the stratosphere, but seeing it in an object with no obvious external heat source is wild.\u201d\u00a0\u00a0<\/p>\n For clues, the team looked in our own backyard, to the planets of our solar system.\u00a0The gas giant planets can serve as proxies for what is seen going on more than 40 light-years away in the atmosphere of W1935.<\/p>\n The team realized that temperature inversions are prominent in planets like Jupiter and Saturn. There is still ongoing work to understand the causes of their stratospheric heating, but leading theories for the solar system involve external heating by aurorae and internal energy transport from deeper in the atmosphere (with the former a leading explanation).<\/p>\n This is not the first time an aurora has been used to explain a brown dwarf observation.\u00a0Astronomers have detected radio emission coming from several warmer brown dwarfs and invoked aurorae as the most likely explanation. Searches were conducted with ground-based telescopes like the Keck Observatory for infrared signatures from these radio-emitting brown dwarfs to further characterize the phenomenon, but were inconclusive.<\/p>\n W1935 is the first auroral candidate outside the solar system with the signature of methane emission. It\u2019s also the coldest auroral candidate outside our solar system, with an effective temperature of about 400 degrees Fahrenheit (200 degrees Celsius), about 600 degrees Fahrenheit warmer than Jupiter.<\/p>\n In our solar system the solar wind is a primary contributor to auroral processes, with active moons like Io and Enceladus playing a role for planets like Jupiter and Saturn, respectively. W1935 lacks a companion star entirely, so a stellar wind cannot contribute to the phenomenon.\u00a0It is yet to be seen whether an active moon might play a role in the methane emission on W1935.\u00a0<\/p>\n \u201cWith W1935, we now have a spectacular extension of a solar system phenomenon without any stellar irradiation to help in the explanation.\u201d Faherty noted. \u201cWith Webb, we can really \u2018open the hood\u2019 on the chemistry and unpack how similar or different the auroral process may be beyond our solar system,\u201d she added.<\/p>\n The James Webb Space Telescope is the world\u2019s premier space science observatory. Webb is solving mysteries in our solar system, looking beyond to distant worlds around other stars, and probing the mysterious structures and origins of our universe and our place in it. Webb is an international program led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.<\/em><\/p>\n Want to help discover a new world? Join the\u00a0Backyard Worlds: Planet 9<\/a>\u00a0citizen science project and search the realm beyond Neptune for new brown dwarfs and planets. Or try NASA\u2019s new\u00a0Burst Chaser<\/a>\u00a0citizen science project, which launched Jan. 9.<\/p>\n Download full resolution images for this article<\/a><\/strong> from the Space Telescope Science Institute.<\/p>\n Right click the images in this article to open a larger version in a new tab\/window.<\/p>\n Laura\u00a0Betz<\/strong> \u2013 laura.e.betz@nasa.gov<\/a>, Rob Gutro<\/strong>\u2013 rob.gutro@nasa.gov<\/a> Christine Pulliam<\/strong> \u2013 cpulliam@stsci.ed<\/a>u Brown Dwarfs<\/strong><\/a><\/p>\n More Webb News<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/latestnews\/<\/p>\n More Webb Images<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/multimedia\/images\/<\/p>\n Webb Mission Page<\/a><\/strong> \u2013 https:\/\/science.nasa.gov\/mission\/webb\/<\/p>\n<\/p>\n What is the Webb Telescope?<\/strong><\/a><\/p>\n SpacePlace for Kids<\/strong><\/a><\/p>\n Ciencia de la NASA<\/strong><\/a><\/p>\n NASA en espa\u00f1ol\u00a0<\/strong><\/a><\/p>\n Space Place\u00a0para ni\u00f1os<\/strong><\/a><\/p>\nImage: Artist Concept Brown Dwarf W1935<\/h2>\n
<\/figure>A Detective Story<\/h2>\n
Image: Spectra W1935 vs W2220<\/h2>\n
<\/figure>Clues from our Solar System<\/h2>\n
Brown Dwarf Aurora Candidates in Context<\/h2>\n
Want to help discover a new world? <\/h2>\n
Downloads<\/h2>\n
Media Contacts<\/h2>\n
NASA\u2019s \u00a0Goddard Space Flight Center<\/em><\/a>,\u00a0<\/em>, Greenbelt, Md.<\/p>\n
Space Telescope Science Institute<\/a>, Baltimore, Md.<\/p>\nRelated Information<\/h2>\n
Related For Kids<\/h2>\n
En Espa\u00f1ol<\/h2>\n
Related Topics<\/h2>\n<\/p><\/div>\n<\/p><\/div>\n