New mission to unlock secrets of Neptune-sized exoplanets launched by scientists

Researchers from the University of Geneva (UNIGE) in collaboration with their global counterparts recently inaugurated the large-scale research. They endeavour a reserach for exploring exoplanets of the size of Neptune. This is known as called ATREIDES. It seeks to find out how planetary systems come into existence and change over time, especially those that revolve around non-solar stars.

• Why Neptunes Matter?

Order of twenty terrestrial masses exo-Neptune planets is remarkably irregular in its appearance. Relatively few of them are discovered by certain of the star environments, known as the “Neptunian desert” region, and more by others, such as the “ridge” and “savanna” region. These distributions retain potential signifiers that involve planetary motion, instability and survival.

• First TOI-421 results

The ATREIDES research team investigated the two-planet system of TOI-421.
One of the planets is a hot Neptune called TOI-421 c that orbits inside the “savanna.” The other interior planet is TOI-421 b. This orbits at larger distances from the star. Interestingly, the two orbits are significantly tilted relative to the star's equator. It is quite unlike our own solar system, where planets all orbit in near alignment. The tilt has processes such as gravitational interactions or planetary migration which have sculpted the system.

• Next Steps for the ATREIDES Programme

The ATREIDES will broaden its research using the very large Telescope of the European Southern Observatory with ESPRESSO and other instruments. This will transit survey data in the programme which will construct the largest comparative sample of exo-Neptunes to date. By analysing their masses, astronomers study atmospheres and orbital alignments. They hope to uncover hidden processes shaping many planetary systems. ATREIDES ultimately aims explaining why some planetary neighbourhoods resemble ours. Others instead follow much more chaotic and erratic evolutionary paths.