Exoplanet with an infernal atmosphere
Data collected by HARPS spectrograph (ESO in Chile) combined with those obtained from the Hubble have allowed Swiss researchers to study in detail the violent, turbulent and very misty atmosphere of HD189733b. The winds blow at over 1000 kilometers per hour.
From the beautiful blue color which is depicted would not seem, but the exoplanet HD189733b is really a hellish planet. At least it’s suggested to the researchers who have published two studies on Astronomy & Astrophysics and respectively, on Astrophysical Journal Letters. Astronomers at the University of Geneva and Bern (Switzerland) were able to measure with extraordinary precision the temperature of this hot Jupiter using two different approaches: the first is based on data collected with the HARPS spectrograph and the second interpretation of traces of sodium in the atmosphere.
The experts came to a conclusion that it’s amazing: the upper atmosphere of HD189733b reaches 3000 ° C (1700 ° C in the low) and the winds blow more than 1,000 miles an hour (sometimes it gets Also at 7000 m / h). You cannot say, therefore, that it is a planet “quiet”. Discovered in 2005 by the method of transit, the planet is orbiting the star HD 189733 A which is 63 light years from the solar system in the direction of the Dumbbell Nebula. The intense cobalt blue color could fool, indicating a planet similar to Earth, where the blue color is given by the water of the oceans. Not so in this case the color is due to its foggy atmosphere and very turbulent.
Within the study Planets National Centre of Competence in Research (NCCR), experts have analyzed the sodium lines in the spectrum and found out that it is an element in the atmosphere of the blue planet and measured by HARPS (installed at the ESO in Chile).
Astronomers know that where there is atmosphere sodium is the source of a signal clearly recognizable, of variable intensity in time when the planet passes in front of its star (transit). This effect was predicted in 2000 before being confirmed two years later by observations of the telescope NASA / ESA Hubble.
Researchers at the University of Geneva have had the idea of using the observations already made by the HARPS spectrometer to study the lines of sodium. Carefully scrutinizing the data collected over many years, Aurélien Wyttenbach, a researcher at the Faculty of Sciences of UNIGE, was able to detect changes in the lines of sodium during various HD189733b transits in front of its parent star. Surprisingly, data analysis HARPS (the most powerful planet hunter on Earth) produced similar data, in terms of sensitivity, to those of the Hubble Space Telescope, but the best in terms of spectral resolution.
In Berne, however, Professor Kevin Heng has developed a new technique to interpret the changes in the lines of sodium, replacing a computer model very sophisticated and complex with a set of simple formulas, which take into account changes in temperature, density and pressure ‘atmosphere. The planet was already known to scholars because orbit 13 times closer to its parent star than Mercury around the Sun, completing an orbit in just 2.2 days. The latest results are exciting because they highlight how much information we can extract from a distant world with limited technologies and methods of simple observation.