The new high-resolution spectrograph PLATOSpec successfully saw its "first light" on 26 November 2024. After almost two years of construction, the instrument is ready for astronomical observations. It will survey stars that potentially host Earth-like extrasolar planets and provide ground support for ESA's upcoming PLATO space mission. The high-resolution spectrograph will be used to study stellar activity and to confirm Jupiter-sized extrasolar planets. The instrument was designed by the PLATOSpec consortium with significant Czech participation and is mounted on ESO's 1.52-metre telescope at the La Silla Observatory in Chile.
PLATOSpec joins a host of other specialised instruments supporting the European Space Agency's (ESA) PLATO mission. The latter plans to launch the PLATO (PLAnetary Transits and Oscillations of stars) mission in 2026, one of its goals being to find Earth-sized exoplanets and even their moons. PLATO will observe thousands of stars. Stars that may have a planetary counterpart must then be screened to select those that will be observed in more detail. Extrasolar planets the size of Earth can only be detected by large telescopes with very high resolution spectrographs. Time at large observatories, such as the European Southern Observatory (ESO), is in high demand, so the most promising candidates must be selected in advance using instruments such as PLATOSpec.
Ground-based star observations from the PLATO mission
A large part of PLATOSpec's observing time is dedicated to ground-based observations of PLATO space mission targets. The new instrument will track stars from the PLATO mission's main set of targets with radial velocity accuracies of up to 2 meters per second (to successfully detect our Jupiter, an accuracy of about 5 m/s is needed for 11 years). The resolving power of the new spectrograph is R=70,000, allowing it to resolve even very narrow spectral lines of gases in the atmosphere of a star, as well as a planet. PLATOSpec observes in the wavelength range from 380 to 700 nanometres because it was designed to be sensitive at blue wavelengths, where spectral lines are particularly useful for measuring the activity level of a star. Stellar activity complicates the detection of extrasolar planets, so understanding the activity of a star and how it changes over time is crucial to finding small extrasolar planets.
PLATOSpec is also equipped with several calibration modes for measuring the Doppler effect of stars. Measuring the Doppler effect is important to the verification process because it allows scientists to calculate the mass of the guide. The greater the shift of lines in the spectrum due to the Doppler effect, the more massive the planetary companion. A special feature of the spectrograph is that the calibration mode can be adjusted to the brightness of the observed star. The instrument will therefore contribute to many areas of science.
PLATOSpec was created by the PLATOSpec consortium. The new spectrograph is located on the 1.52-meter diameter telescope at the La Silla Observatory in Chile, which belongs to the European Southern Observatory (ESO). The TOPTEC Centre - a department of the Institute of Plasma Physics of the CAS - upgraded the front of the telescope using special octogonal optical fibres with an innovative light injection system. The telescope and spectrograph will be remotely controlled either from Ondrejov or Brno in the Czech Republic, from Tautenburg in Germany or from Santiago de Chile.
Peter Kabáth, scientist at the Astronomical Institute of the Czech Academy of Sciences and project leader, is pleased that PLATOSpec is now fully operational: "PLATOSpec is a great example of how older telescopes can still be very useful. The 1.52 metre diameter telescope started operating in the 1960s and was decommissioned in 2002. Now our state-of-the-art spectrograph will provide a new and very interesting program."
Pavel Pintr, TOPTEC team leader from the Institute of Plasma Physics of the CAS, explains the reasons for the optical upgrade of the 1.52 m telescope: "Optical upgrades have increased the efficiency of the telescope, so fainter stars can be observed with the high precision associated with the spectrograph. The system we designed and built The injection of light from the telescope into the filament is a new innovative part of the telescope and according to the first measurements it turns out to be very effective."
"I am very happy that Masaryk University has joined this amazing project and students of all levels of astrophysics studies at the Faculty of Science will be able to use the data in their final theses.", says Jan Janík, team leader at the Institute of Theoretical Physics and Astrophysics, Faculty of Science, MU.
Marek Skarka from the Exoplanet Research Group of the Astronomical Institute of the CAS adds: "The whole project is an example of perfectly functioning international cooperation. However, it is also a demonstration that there are enough excellent institutes and companies in the Czech Republic that are able to supply the components of a modern automatic telescope."
Artie Hatzes, a scientist at the Thuringian State Observatory in Tautenburg, explains why PLATOSpec is such an important instrument for all the consortium partners.Most of the consortium partners are located in the northern hemisphere. PLATOSpec gives us access to the night sky of the southern hemisphere and allows us to perform ground support for the PLATO mission, which will observe stars in the southern sky."
Leonardo Vanzi, professor at Pontificia Universidad Católica de Chile, Santiago, Chile, created the optical design of PLATOSpec and oversaw its construction:"We got the first light on schedule. We are now ready to study stellar activity in detail and support the PLATO mission."
Members of the PLATOSpec consortium are:
- Institute of Astronomy, Czech Academy of Sciences, Ondřejov, Czech Republic (telescope and front-end modernization)
- Thuringian State Observatory Tautenburg, Germany (calibration unit)
- Pontificia Universidad Católica (PUC) de Chile, Santiago, Chile (design and construction of spectrograph),
- Universidad Adolfo Ibáñez, Chile (data processing and data pipeline)
- Masaryk University, Czech Republic
- TOPTEC Research Centre - Institute of Plasma Physics of the CAS
- University of Graz, Austria.
Funding for the PLATOSpec project is provided by:
- Astronomical Institute of the Czech Academy of Sciences,
- grant LTT-20015 of the Ministry of Education, Sports and Youth of the Czech Republic,
- by the Thuringian Ministry of Economy, Science and Digital Society under the "Research Promotion Guidelines",
- the Chilean "Agencia Nacional de Investigación y Desarrollo" (ANID): projects FONDECYT 1241963, FOVI220091
- bilateral grant funded by the Czech Science Fund GAČR (22-30516K) and the Austrian Science Fund FWF (10.55776/I5711)
- institutional support for the development of Masaryk University's research organisation
Institute of Astronomy of the CAS/ gnews - RoZ
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