Astronomers have identified an exoplanet that has a truly turbulent atmosphere, with wind speeds of more than 1,000 kilometres per hour and a temperature that skyrockets to 3,000 degrees.
Researchers from the Universities of Geneva (UNIGE) and Bern, Switzerland, measured the temperature of the atmosphere of the exoplanet with unequalled precision, by crossing two approaches.
The first approach was based on the HARPS spectrometer and the second consists of a new way of interpreting sodium lines.
From these two additional analyses, researchers have been able to conclude that the HD189733b exoplanet is showing infernal atmospheric conditions: wind speeds of more than 1000 kilometres per hour, and the temperature being 3000 degrees.
"With a temperature of 3000 degrees and such winds blowing at several thousand kilometres per hour, the HD189733b exoplanet's atmosphere is truly turbulent," researchers said.
When there is an atmosphere, sodium is the source of a clearly recognisable signal, whose intensity varies at the time when the planet passes before its star, an event called transit.
By attentively scrutinising the data collected over many years, Aurelien Wyttenbach, a researcher at the UNIGE Faculty of Science, has been able to detect variations in sodium lines during several transits of HD189733b.
Surprisingly, the analysis of HARPS data on Earth produces an equivalent detection, in terms of sensitivity, to that of the Hubble space telescope, but much better in terms of spectral resolution.
"It is this last aspect which has enabled an analysis to be achieved, which is a lot finer than previously, and this despite a telescope whose diameter remains modest," researchers said in the study published in the Astronomy & Astrophysics Journal.
Alongside this, and in another study appearing in the Astrophysical Journal Letters, Professor Kevin Heng, at Bern University, has developed a new technique of interpreting variations in sodium lines.
Instead of using a sophisticated computer model, Heng resorts to a set of simple formulae, which enable variations in temperature, density and pressure to be expressed within an atmosphere.
