Researchers reveal findings after peering into atmosphere of hottest planet

Washington D.C. [USA], April 9 (ANI): After peering into the scalding atmosphere of the ultra-hot Jupiter planet, researchers have reported the findings in a new study. In the study led by Jake Turner of Cornell University, a team of scientists digs deep into the transmission spectrum for the exoplanet KELT-9b.
The study was published in the journal of the American Astronomical Society.
KELT-9b is an extreme world. Clocking in with a dayside temperature of more than 4,500 K (~7,600 °F), it is the hottest planet known — hotter than many stars! This ultra-hot Jupiter orbits at a mere 0.035 AU from its scalding A- or B-type host star, whizzing around its host in just 1.5 days.
The intense radiation bombarding KELT-9b almost certainly takes a toll: this energetic light should dissociate molecules into their component atoms and ionize metals in the hot atmosphere, and it may inflate the envelope of hydrogen gas around the planet to the point where the hot gas escapes.
Turner and collaborators explore the extreme conditions in KELT-9b’s atmosphere with high-resolution transmission spectra taken with the CARMENES instrument on the Calar Alto 3.5-m telescope in Spain.
The authors find absorption lines indicating the presence of ionized calcium, Ca II, in KELT-9b’s atmospheric spectra; this is just the second time that Ca II has been observed in a hot Jupiter’s atmosphere. They also find prominent Ha absorption — evidence that confirms the existence of an extended envelope of hydrogen surrounding the irradiated planet.
By modeling the spectra they obtain for KELT-9b, Turner and collaborators are able to identify the pressures, altitudes, and temperatures at which these spectral lines form in the atmosphere. They find that the Ca II lines probe the atmosphere at an altitude of about 1.32-1.40 times the planet’s radius. The Ha line provides information from higher up, at 1.44 planetary radii.
Together, these absorption lines act as atmospheric thermometers, providing a picture of KELT-9b’s atmospheric temperature profile and yielding insight into the energy that enters and leaves the planet’s atmosphere.
These results demonstrate the power of this technique, revealing the remarkable wealth of information we can glean from some distant starlight filtered through the atmosphere of an extreme world. (ANI)