Observations made by the Cheops space telescope of the European Space Agency (ESA) concluded the presence of a exoplanet shaped like a rugby ball.
The exoplanet WASP-103b is considered the first oval-shaped to be discovered.
According to the researchers, it is in the Hercules constellation and it looks like that because has been deformed by strong tidal forces between the planet and its host star WASP-103.
“This exoplanet it takes less than a day to circle its star and its shape is more similar to that of a rugby ball than to that of a sphere ”, states Jorge Lillo-Box, researcher at the Center for Astrobiology (CAB, CSIC-INTA), who has participated in the preparation of this study, The results of which were published on Tuesday 11 in the journal Astronomy & Astrophysics. “We had theorized about these planetary deformations, but this is the first time that we have verified it with observations”.
The action of the tidal forces
On Earth, the tides in the oceans are mainly due to the slight jerks exerted by the Moon on our planet when orbiting it. The Sun also does the same, however, its great distance from the Earth prevents it from causing major deformations on the Earth’s surface.
In this case, the star around which this exoplanet revolves has a similar temperature and is about 1.7 times bigger than our Sun. For its part, the exoplanet is a gas giant planet with almost twice the size of Jupiter and 1.5 times its mass.
According to astronomers, this proximity so great May cause monumental tides, which deform the exoplanet and make it have that characteristic elongated shape.
Using new data from the Cheops space telescope of the ESA, combined with previous data obtained by the Hubble Space Telescope and the Spitzer Space Telescope, the astronomical community has been able detect how tidal forces deform exoplanet WASP-103b, giving it an oval shape. These data have been complemented with high spatial resolution images from the AstraLux instrument at the Calar Alto Observatory (Almería), thanks to which the origin of the signal has been confirmed.
Latent mysteries surrounding the discovery
The discovery of WASP-103b still has mysteries unsolved. Tidal interactions between a star and a Jupiter-sized planet so close should make the orbital period of the planet shorten, gradually bringing it closer to the star before it I was finally swallowed by this.
However, measurements of WASP-103b seem to indicate that the orbital period could be increasing and that the planet is slowly moving away from the star. This would indicate that, in addition to tidal forces, there must be other factor that is influencing the planet.
“The team has raised the possibility of the presence of a companion star that could affect the dynamics of the system’s movements or make the orbit slightly elliptical ”, says David Barrado, a researcher at the CAB. “We have not been able to confirm or refute this possibility, so it will be necessary to carry out more observations of the system in order to reveal what is causing the planet to move away from the star ”.