Cover image adapted from ESO / L. Sidewalk – CC BY 2.0 (links below)
An international group of researchers led by a team at the University of Geneva has found an exoplanet with an atmosphere that is doing something you do not see every day, even if you have a powerful spectrograph with an insanely long name at your disposal.
Using the high-resolution Calar Alto search for M dwarfs with Exoearths with optical and near-infrared (CARMEN) spectrometers installed in the 4-meter-long telescope in Calar Alto, Spain, the researchers noted that helium escaped from the atmosphere of a planet 124 light years from Earth. According to reports, the exoplanet designated HAT-P-11b has a helium cloud extended around it that is "swollen" like a balloon. With CARMENES, the team managed to separate the light from the host star into a spectrum that revealed the helium atoms in the exoplanet's atmosphere. "This is a really exciting discovery, especially since helium was only detected in exoplanet atmospheres for the first time earlier this year," said Jessica Spake of Exeter University's physics and astronomy department in a statement. "The observations show the helium being expelled from the planet by the radiation of its host star."
The data also show that the planet is 20 times closer to its host than our Sun, which may explain the effect in its atmosphere. "We suspect that this proximity to the star could impact the atmosphere of this exoplanet," said Romain Allart, a PhD student at the University of Geneva and the first author of the study published recently in the journal. Science. "The new observations are so precise that the exoplanet atmosphere is undoubtedly [sic] inflated by stellar radiation and escapes into space. "I hope we can use this new study to learn what types of planets have large envelopes of hydrogen and helium, and for how long they can retain the gases in their atmospheres," Spake added.
Like a balloon losing its helium, we imagine HAT-P-11b spitting and flying through space, but there is no evidence to support this mental image.
Cover image adapted from ESO / L. Sidewalk – CC BY 2.0