JUPITER, a laboratory for studying exoplanets
18/02/2015
A team of astronomers led by the Severo Ochoa postdoctoral researcher at the IAC Pilar Montañés has analized the planet's atmosphere during an eclipse of Ganymede, the third satellite of the gas giant
The scientific journal Astrophysical Journal Letters is publishing a study, led by researchers at the Astrophysical Institute of the Canaries (IAC), which has been the subject of a report in the journal Nature. In the study Jupiter is presented as an ideal laboratory for research into exoplanets which are similar. Jupiter, the largest planet in the Solar System, has large satellites around it. The study has used the largest of the satellites, which is also the biggest satellite in the Solar System, Ganymede, as a mirror to analyze the atmosphere of the planet. The observations were performed during an eclipse of Ganymede by Jupiter, and allowed the researchers to observe Jupiter as if it were a transiting exoplanet.
Its transmision spectrum, observed as Ganymede began to be eclipsed, and could be observed through the atmosphere of Jupiter, shows strong extinction, reduction of the light due to clouds and to aerosols in Jupter´s atmophsere, as well as strong absorption in the characteristic bands of methane (CH4), and most surprising, ice crystals in a stratospheric layer. These results are of relevance to the modelling and the interpretation of transiting exoplanets, but they also offer a new technique to characterize the upper layers of Jupiter’s atmosphere, and to determine the abundance of water. It will also be useful in establishing the rate of comet impact on Jupiter, and its consequences for the history of the formation of the Solar System.
Publication: "Jupiter as an exoplanet: UV to NIR transmission spectrum reveals hazes, a Na layer and possibly stratospheric H2O-ice clouds". ApJ Letters. E. preprint http://arxiv.org/abs/1502.02132
Authors: Montañés-Rodríguez, P. (IAC); González-Merino, B. (IAC); Pallé, E. (IAC); López-Puertas, M. (IAA, CSIC); García-Melendo, E. (UPV).
Further information, image and animation: IAC press release
