Tarmo Haud

Tartu becomes a space mission centre at the end of April

On 23–26 April 2024, Tartu Observatory will host scientists and engineers from the Ariel consortium. The European Space Agency's Ariel mission, which also closely involves Estonians, will be launched in 2029. Ariel is the first telescope entirely dedicated to measuring the chemical composition and thermal structures of exoplanet atmospheres. During its 4-year mission, Ariel will study what exoplanets are made of, how they formed, and how they evolve. 

Top scientists and experts in the field will come to Tartu to share new developments in space missions with consortium members. Tartu Observatory and companies in the field of space exploration will showcase the activities and capabilities of the Estonian space technology landscape.  

Tartu Observatory's method helps to select planets for observation

For the mission to succeed, the right planets must be chosen for observation. To select the planets to be observed, the stellar physicists of Tartu Observatory will carry out a preliminary study to determine the basic parameters of the planets' parent stars and their chemical element content. Determining the properties of the parent stars using a single method ensures the accuracy and consistency of exoplanet atmospheric studies. Research Fellow in Stellar Physics Heleri Ramler explains that the use of a single method avoids propagating errors in the methods themselves to the input of subsequent parameters. "For example, what I am doing now – determining the parameters of hot stars – has been done in the past by many other research teams, but they have used different codes and models. We are not in a position to judge which of these earlier results is the best input to the preliminary study of the Ariel mission." The Tartu Observatory method is used in the Ariel mission for hot stars until the end of the mission when it becomes known where errors occur which can then be prevented from intertwining with errors from other sources.  

The planetary observation timetable is based on data from Tartu Observatory

One of the key tasks of Ariel is to measure the spectra of exoplanet atmospheres, and the cornerstone of its success is to create an observation schedule that is as accurate as possible. Exoplanets orbit their parent star, and their atmospheric spectrum can only be measured when starlight shines through it. Observations must therefore be timed so that the planet passes in front of the star as seen from the point of view of the telescope. So that the telescope does not have to idle in space waiting for a planet to become visible, stellar physicists at Tartu Observatory calculate when planets will be visible to the telescope and use this data to draw up an observation schedule.

Since the time of a planet's passage from a star can gradually shift over the years, a large number of objects need to be monitored continuously throughout the mission. For this purpose, telescopes from all over the globe will be deployed and astronomers from Tõravere will also help with photometric observations. Amateur astronomers will also be involved.

The mission aims to find answers to the questions science currently has about planet formation.

The conference is supported by the City of Tartu and Estonian Research Council within the ESA BIC Estonia Consortium project.


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