That’s fast! – SCITECHSS Group

A team of astronomers, with the participation of Scitechss members, has detected very powerful winds and significant temperature variations in the atmosphere of the giant exoplanet WASP-127b located over 500 light-years from Earth. The discovery was made using the CRIRES⁺instrument mounted on one of the European Southern Observatory’s Very Large Telescope (ESO’s VLT) in Chile.

This artist’s visualisation of WASP-127b, a giant gas planet located about 520 light-years from Earth, shows its newly discovered supersonic jet winds that move around the planet’s equator. With a speed of 9 km per second (33 000 km/h), this is the fastest jetstream of its kind ever measured in the Universe. By tracking the speed of molecules in the atmosphere with the CRIRES+ instrument on ESO’s Very Large Telescope, researchers found that one side of the planet’s atmosphere is moving towards us and the other away from us. This indicates that there is a powerful wind current going around the planet. Credit: ESO/L.Calçada

WASP-127b is a type of exoplanet known as a “hot Jupiter” because it has a size similar to Jupiter of our own Solar System, but with a much hotter atmospheric temperature (T_atm~1400K). Such hot temperature results from a very short orbital distance: WASP-127b is hundred times closer to its host star than Jupiter to the Sun!

Using the method of transit spectroscopy, the authors detected a double-peaked velocity profile of the atmospheric material. This discovery indicates that part of the atmosphere is moving toward us at an astonishing 9 km/s (33,000 km/h), while another part is moving away from us at the same speed, suggesting the presence of a powerful jet wind circulating at supersonic speed at the equator of the planet. This jet moves nearly six times the speed at which the planet rotates. It is the fastest wind ever measured on any known planet so far. In comparison, the fastest wind ever measured in the Solar System was found on Neptune, moving at ‘only’ 0.5 km/s (1800 km/h).

The results of this study provide a foundation for further investigations into exoplanet atmospheres with a goal to understand chemical and dynamical pathways that led to the formation of these extraordinary planets. This, in turn, can also help us to learn more about the history of our own Solar System as well.

The work demonstrates how high-resolution instruments like CRIRES⁺allow astronomers to map the weather patterns of distant worlds, even without being able to directly observe their surfaces. WASP-127b, with its unique atmospheric characteristics and rapid winds, provides a fascinating case study of atmospheric dynamics on planets far beyond our solar system.

More information

This research was presented in the paper “CRIRES⁺Transmission Spectroscopy of WASP-127b: Detection of Resolved Signatures of a Supersonic Equatorial Jet and Cool Poles in a Hot Planet” published today in Astronomy & Astrophysics. (Link:
https://doi.org/10.1051/0004-6361/202450438)

Also check out the video prepared by ESO: https://cloud.iaa.es/index.php/s/wxYw7apw75MQYmx

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