An article published in the journal “Astronomy & Astrophysics” reports a study of the exoplanet Wasp-103b that offers evidence of its oval shape. A team of researchers used data collected by ESA’s CHEOPS space telescope to have the accuracy needed to assess this gas giant’s anomalous shape. It’s due to its star’s powerful tidal forces, as the star is a bit larger and more massive than the Sun, on this planet due to their proximity. In fact, Wasp-103b is so close to its star that its year lasts a little less than an Earth day.
The CHEOPS Space Telescope was launched on December 18, 2019, to examine exoplanets and obtain accurate data on them. About 1,800 light-years from Earth, Wasp-103b is a gas giant whose discovery was announced in 2014, in “Astronomy & Astrophysics”. Its proximity to its star was immediately seen as its most peculiar feature, which includes it in the class of the so-called ultra-short-period planets.
Since its discovery, astronomers indicated likely out-of-normal effects of the star Wasp-103 on its planet. In the 2014 announcement, Wasp-103b was defined as a planet on the edge of tidal destruction due to the danger it runs of getting even closer to its star to the point of being destroyed by it.
Observations conducted with various telescopes made it possible to ascertain that Wasp-103b has a mass that is about 1.5 times Jupiter’s. However, they couldn’t assess this exoplanet’s characteristics with sufficient precision to allow them to understand its fate.
Progress was made thanks to the CHEOPS space telescope, which offered such precision that it could also detect the exoplanet Wasp-103b’s deformation in the observations of its passages in front of its star. Kate Isaak, ESA’s CHEOPS project scientist, stated that this study is an excellent example of the diverse questions exoplanet scientists tackle with CHEOPS, illustrating the importance of this flexible mission for follow-up studies.
The precision of the data on Wasp-103b collected by the CHEOPS space telescope, combined with data collected with the Hubble and Spitzer space telescopes, made it possible to obtain information on the distribution of mass within it. Susana Barros of the Instituto de Astrofísica e Ciências do Espaço and University of Porto, Portugal, explained that the resistance of a material to deformation depends on its composition, so by measuring its deformation we can tell how much of it is rocky, gaseous, or water.
The exoplanet Wasp-103b has a similar composition to Jupiter but is larger probably because its atmosphere is inflated by the heat received from its star. Despite the new information, the authors of this study have not yet been able to give an answer regarding its fate. Even taking advantage of the CHEOPS space telescope’s accuracy, more observations will be needed and now that the James Webb has finally been launched, the study of Wasp-103b could also take advantage of it with the possibility of discovering other hot Jupiters near stars massive enough to deform them.
