Astronomer from the UNAB Institute of Astrophysics Publishes in the Prestigious Journal Nature Astronomy

Claudio Cáceres, a leading astronomer at the Institute of Astrophysics at the Universidad Andrés Bello (UNAB) and researcher at the Center for Astrophysics and Related Technologies (CATA), has devoted his most recent research to understanding the atmospheres of planets outside our solar system. He recently published his findings in the prestigious scientific journal Nature Astronomy. The co-authored paper is entitled «Nightside clouds and disequilibrium chemistry on the hot Jupiter WASP-43b». It focuses on the study of an extremely hot and massive exoplanet located in the constellation Sextant, visible from the southern hemisphere.

«It is always very exciting to participate in research projects that have a great impact and recognition,» says Cáceres, highlighting the importance of this research, which allows us to characterize the atmosphere of extrasolar planets using the world’s most advanced telescope, the James Webb Space Telescope (JWST). This achievement, he explained, is just a foretaste of what will be possible with the next giant telescopes under development in northern Chile, such as the Extremely Large Telescope (ELT) and the Giant Magellan Telescope (GMT).

A detailed analysis of the atmosphere of the exoplanet WASP-43b

Exoplanet WASP-43b / Image credit: NASA, ESA, CSA, Ralf Crawford (STScI)

Claudio Cáceres’ most recent research focuses on the exoplanet WASP-43b, categorized as a «hot Jupiter.» These extrasolar planets are Jupiter-like gas giants that orbit their stars at very short orbital distances so that their periods reach, at most, a few days. Because of their close proximity to their star, they receive a lot of radiation, which causes their illuminated atmosphere to be very hot, hence the name.

WASP-43b has twice the mass of Jupiter and completes one orbit around its star in 0.81 days, i.e., its «year» lasts only 19 hours. This exoplanet is characterized by an extreme temperature that reaches 1250ºC on the day side and about 590ºC on the night side. This thermal difference generates intense winds, similar to jet streams, and unbalanced atmospheric phenomena.

«We noticed that during the day it is mostly clear, and during the night it is always cloudy, with very opaque clouds that block almost all infrared radiation,» explains the researcher. This is the first time in human history that such observations have been possible, thanks to the advanced technology of the James Webb Space Telescope.

The study compares the planet’s emission and transmission spectra, revealing how its atmosphere responds to its environment’s extreme conditions. In simple words, says Cáceres, «it is like understanding the climate of a planet 284 light-years away».

Implications for the Search for Life in the Universe.

The academic from the UNAB Astrophysics Institute highlights the relevance of this research in a broader context: «The most important thing is that it allows us to understand that nature has planets that are very different from those we find in our Solar System.»

For Professor Cáceres, this is important because if the objective is to find planets that can harbor life, «then we have a wider range of objects to search and, similarly, the chances that life can be found on another planet are greater because there is a greater diversity of environments in our galaxy,» he explains, adding:

For now, this work seeks to understand how the atmospheres of extremely hot giant planets behave. Still, it provides a basis for further investigation of the cooler planetary objects in our environment.

In addition to this recent publication in Nature Astronomy, since March of last year, Professor Claudio Cáceres has published another in the same journal on the exoplanet WASP-39b, and three publications in the prestigious journal Nature, where he deals with the exoplanetsWASP-18b and WASP-39b (issues7949 and8001). Each of these papers is part of a larger project to test the ability of the new instruments on board the James Webb Space Telescope to detect and analyze exoplanet atmospheres.

UNAB Contributes to the Training of New Astronomers

This research not only provides valuable data to the scientific community but also directly influences student training. In this sense, Claudio Cáceres highlights the relevance of the work of the Faculty of Exact Sciences, the Institute of Astrophysics, and the Department of Physical Sciences of the UNAB in preparing the new generations of astronomers and astronomers. He also adds:

There is still much to be discovered in the world of exoplanets, and the new instruments being developed promise a spectacular future for the field. This means a tremendous opportunity for the students we train, which I am sure they will take advantage of.