More than 4000 exoplanets have been discovered so far, and this number is still growing rapidly! However, we know very little about them: What are they made of? What are the conditions there? How did they form and how did they evolve? ESA’s M4 mission, Ariel, will observe spectroscopically around 1000 exoplanets to further characterise their atmospheres and try to answer these questions.
Exoplanets is one of the few fields that amateur astronomers and the public can contribute significantly, with observations with small and medium scale telescopes. I the case of Ariel, small and medium size telescope are valuable, in order to plan the observations as efficiently as possible. To achieve this, a good knowledge of the planets’ ephemerides is needed before the launch of Ariel in 2028. While ephemerides for some planets are being refined on a per-case basis, an organised effort to collectively verify or update them when necessary does not exist.

In this session, we will present the Ariel mission and will introduce the ExoClock project, an open, integrated and interactive platform with the purpose of producing a confirmed list of ephemerides for the planets that will be observed by Ariel. The project has been developed in a manner to make the best use of all available resources: observations reported in the literature, observations from space instruments and, mainly, observations from ground-based telescopes, including both professional and amateur observatories. To facilitate inexperienced observers and at the same time achieve homogeneity in the results, we created data collection and validation protocols, educational material and easy to use interfaces, open to everyone. ExoClock was launched in September 2019 and now counts over 160 participants, mostly amateur astronomers, who’ve already observed 1200 transits for 170 exoplanets.

The session will start with Giovanna Tinetti from UCL, the Principal Investigator of the Ariel Mission, who will present the concept and the goals of the mission and will continue with Athanasia Nikolaou from Sapienza who will present the prospects of Ariel for small planets. Next, Anastasia Kokori from UCL, coordinator of the ExoClock project, will share the scope and the principals of the ExoClock Project, while Martin Crow, an active ExoClock observer form the British Astronomical Association, will share his experience from observing exoplanets and participating to ExoClock. Finally, Angelos Tsiaras from UCL, coordinator of the ExoClock project, will demonstrate how to analyse exoplanet observations with the dedicated, user-friendly tools developed for the project.

The ExoClock project website: www.exoclock.space

Educational material can be found at: www.exoworldsspies.com

Draft Agenda:

- The Ariel mission. Giovanna Tinetti

- Planetary Perspectives of Ariel: Looking at the tree and adding the forest. Athanasia Nikolaou

- The ExoClock project: How amateurs can contribute to Ariel. Anastasia Kokori.

- Experiencing ExoClock with an active participant. Martin Crow

- Analysing exoplanet observations. Angelos Tsiaras