European astronomers have discovered an extremely unusual exoplanet, in which clouds of titanium oxide - the strongest greenhouse "gas" that can heat its upper layers to hellish high temperatures, hang in its atmosphere, and published the results of their observations in the journal Nature.
“The presence of titanium oxide in the atmosphere of WASP-19b can have an extremely unusual effect on how its different layers are heated and how the air flows in it. The fact that we were able to study it in such detail makes us very happy and suggests that we can carry out similar observations for other planets,”said Ryan MacDonald from the University of Cambridge (UK).
Astronomers call "hot Jupiters" heated gas giants that are only 2.2-75 million kilometers away from their stars. In the solar system, even Mercury approaches a star no closer than 46 million kilometers, and therefore really hellish temperatures reign in the atmospheres of such planets - 1000-1300 degrees Kelvin.
Finding such planets is much easier than other celestial bodies, and they make up most of the exoplanets known to science. The discovery of "hot Jupiters" for the first time presented scientists with the fact that the atmosphere on such planets can consist of extremely exotic materials. For example, in recent years, planets with lead and glass clouds have been discovered, as well as air consisting of evaporated metals and rocks, in the upper layers of which it sometimes rains from rubies and sapphires.
Relatively recently, according to MacDonald, scientists discovered several "hot Jupiters", whose atmospheres were heated to even higher temperatures exceeding 2.5 thousand Kelvin, and had an unusual structure - they were hotter on the outside and colder on the inside, like the stratosphere of the Earth. The presence of such a layer on them led scientists to assume that the atmosphere of these "hot Jupiters" is heated by some super-powerful greenhouse effect, which can be generated by two substances - titanium oxide or vanadium oxide.
MacDonald and his colleagues proved that this is so in fact, studying the spectrum of the planet WASP-19b, discovered four years ago in the constellation Sails near a star similar in size and mass to the Sun. This planet makes one revolution around its star in just 18 hours, which allows scientists every day to observe how the rays of the luminary pass through its atmosphere and interact with its molecules, taking with them information about its chemical composition.
Having traced several dozen times how the star's light "pierces" the atmosphere of WASP-19b, planetary scientists were able to separate real signals from noise and reveal its chemical composition. It turned out that this "hot Jupiter" was an extremely exotic and hot planet.
Its atmosphere, as shown by the measurements of scientists, consists of incandescent water vapor, sodium, helium and hydrogen, and its upper layers are covered with layers of hydrocarbon fog and "titanium" clouds. Thanks to this, the "stratosphere" of WASP-19b is heated to two thousand degrees Kelvin, which makes it one of the most sultry "hot Jupiters" known to astronomers.
Promotional video:
Such a discovery, McDonald and his colleagues emphasize, is important in that it demonstrates that scientists can uncover the exact chemical composition of distant planets using ground-based telescopes. In turn, the launch of the James Webb Space Telescope will make it possible to conduct similar observations of smaller and hotter planets, more interesting from the point of view of searching for a potential homeland of extraterrestrial life, scientists conclude.
