Astronomers using the powerful James Webb Space Telescope (JWST) have detected signs of auroral activity on an isolated brown dwarf outside the Solar System. Known as W1935, the failed star is more massive than Jupiter but lacks the mass required to sustain nuclear fusion and become a real star. It also exhibited infrared emissions from methane, a finding that has puzzled scientists due to the brown dwarf’s cold nature and its lack of a host star to provide energy for such atmospheric phenomena.
The results, published this week in Science Advances, suggest that methane comes from another source. Specifically, it could be from a hot spot on the brown dwarf’s surface, its magnetosphere, or both. The discovery of these enigmatic aurorae marks one of the many exciting milestones of JWST’s mission to study our Universe.
Like its predecessor, Hubble, Webb will continue to observe the Universe as it changes over time – from icy Kuiper Belt objects that orbit our Solar System to blazing quasars at the center of distant galaxies. The telescope will also look for Earth-sized and more giant exoplanets, search for remnants of the Big Bang, and probe the earliest stars and galaxies to understand better how our galaxy grew from its humble origins into the cosmic giant we see today.
As Webb reaches its full scientific maturity, it will deliver breathtaking images and discoveries. It’s easy to imagine what future generations of astronomers will be able to accomplish with the power of this extraordinary telescope.
Webb is the most sophisticated telescope built to date and one of the most ambitious. Its enormous mirrors and sophisticated instruments will enable it to peer deeper into the cosmos than any previous telescope, with resolutions allowing astronomers to detect fine details of planetary atmospheres and even the spectra of exoplanets.
To make that possible, the telescope conducts observations from a distance of 1.5 million kilometers from Earth, at a point in space called Lagrange L2, where the gravitational pulls of two or more orbiting bodies balance out. Its far-flung location ensures that Webb won’t be subject to damage from debris from other celestial bodies, and it allows the observatory to see more of the sky than Hubble ever did.
When it’s fully operational, Webb will be operated by the Space Telescope Science Institute at NASA’s Goddard Space Flight Center in Baltimore. As the telescope cools and its mid-infrared instruments are calibrated for crisp observation, the institute will monitor the craft and lead it through a wide array of scientific studies. However, it will have to wait a bit longer before the first official observations are made. The observatory’s mid-infrared spectrograph, MIRI, must cool to 7 Kelvin, around 450 degrees below zero Fahrenheit. After that, astronomers will begin asking the telescope questions about our Milky Way, distant galaxies, and the interstellar medium.
