Specialists have shared insights about an untethered planet traversing our Solar System, with its changing brightness attributed to infrared radiation.
The object, termed SIMP 0136 in scientific discussions, was initially tracked by ground-based observatories alongside NASA’s Hubble and Spitzer space telescopes.
Currently, it is being examined more thoroughly using the James Webb Space Telescope, leading to some significant findings.
The planet’s three-dimensional complexity is believed to arise from a ‘complex combination of atmospheric factors,’ and it is estimated to be about 13 times the mass of Jupiter, the largest planet in our Solar System (1.899 x 1027 kg).
Because of its brightness and isolation from other celestial bodies, SIMP 0136 has been labeled the ‘ideal target for exo-meteorology.’
Due to its solitary nature and lack of orbit around a star, it can be observed with minimal light interference or variability from a host star, as noted by NASA.
Positioned about 20 light-years away in the Milky Way, the planet also boasts a rotation period of 2.4 hours, allowing the Webb Telescope to capture images efficiently for researchers’ evaluation.
Allison McCarthy, a doctoral candidate at Boston University and lead author of a study published in The Astrophysical Journal Letters, discussed the research on SIMP 0136.
“We already knew that it varies in brightness, and we were confident that there are patchy cloud layers that rotate in and out of view and evolve over time,” she elaborated on previous studies.
“We also thought there could be temperature variations, chemical reactions, and possibly some effects of auroral activity affecting the brightness, but we weren’t sure.”
To delve deeper into the nature of this untethered object, the team utilized the Webb Telescope’s Near-Infrared Spectrograph (NIRSpec) and Mid-Infrared Instrument (MIRI) for detailed measurements of brightness changes across various wavelengths.
“To see the full spectrum of this object change over the course of minutes was incredible,” remarked Johanna Vos, principal investigator from Trinity College Dublin.
“Until now, we only had a little slice of the near-infrared spectrum from Hubble, and a few brightness measurements from Spitzer.”
In their published results, scientists found that some infrared light wavelengths were emitted by patchy clouds made of iron particles.
Other wavelengths were linked to clouds believed to consist of tiny grains of silicate minerals, with additional wavelengths coming from ‘bright hot spots’ high above the clouds.
The brightness of SIMP 0136 is understood to be due to variations in infrared radiation. As it rotates, the light level changes and is not uniform across its surface.
Explaining these unusual findings, McCarthy noted: “Different wavelengths provide information about different depths in the atmosphere.
“We started to realize that the wavelengths that had the most similar light-curve shapes also probed the same depths, which reinforced this idea that they must be caused by the same mechanism.”
Researchers assert that these ‘exciting’ results indicate that molecules such as methane and carbon dioxide can vary across different locations over time.
Nonetheless, Vos mentioned: “We haven’t really figured out the chemistry part of the puzzle yet.
“If we are looking at an exoplanet and can get only one measurement, we need to consider that it might not be representative of the entire planet.”