Have you ever looked up at the night sky and wondered if there are other planets out there beyond...
While the first type involves pointing a telescope at a star and taking a picture of its companion, the second type of method focuses, for example, on observing small dips in the apparent brightness of a star when a planet passes in front of it or on detecting minute oscillations in the position of a star caused by an orbiting planet.
In addition to these missions, specifically developed for the search and characterisation of exoplanets, another mission plays a key role in this field: Gaia.
Monitoring star positions over long periods of time, as Gaia does, reveals tiny motions caused by otherwise unseen planets orbiting them.
With two major data releases still to come, DR4 and DR5, Gaia will produce all-sky exoplanet catalogues containing thousands of new planets.
Gaia will not be able to find any "Earth twin"; nevertheless, adding planets to the catalogue is important: a larger sample allows us to better understand the characteristics and occurrences of the different types of planets that make up the exoplanet zoo.
"Knowing the characteristics of exoplanet host stars is fundamental. In fact, stars and planets interact directly with each other. The star plays a fundamental role in the evolution of the planet: the same planet around a different star could have developed in a completely different way. For this reason, it is important to know the characteristics of the star, and this knowledge provided by Gaia is increasingly recognised within the exoplanet community."Theresa Lüftinger, ESA Ariel Mission Project Scientist.
In conclusion, Gaia emerges as a crucial catalyst for the study of exoplanets.
With the upcoming fourth data release, Gaia is expected to unveil thousands of new planets that will complement the exoplanet zoo we know to date.
Gaia will continue to contribute to the characterisation of the host stars of planets, enabling a better understanding of the formation and evolution of planetary systems.
Gaia opens new avenues in the search for and study of exoplanets, enriching our understanding of the Universe and its diverse planetary facets.