Hungarian experts also contributed in the development of ESO’s new infrared interferometer

The new MATISSE instrument on ESO’s Very Large Telescope Interferometer (VLTI) has now successfully made its first observations at the Paranal Observatory in northern Chile. MATISSE is the most powerful interferometric instrument in the world at mid-infrared wavelengths. Hungarian researchers and engineers from Konkoly Observatory also contributed to the realization of the instrument by technical design, software development, and equipment testing, for which Hungarian astronomers will have guaranteed telescope time to use MATISSE.

7 March, 2018

MATISSE (Multi AperTure mid-Infrared SpectroScopic Experiment) observes infrared light — light between the visible and microwave wavelengths of the electromagnetic spectrum, covering wavelengths from 3–13 micrometres (µm). It is a second-generation spectro-interferometer instrument for ESO’s Very Large Telescope that can take advantage of multiple telescopes and the wave nature of the light. In this way, it produces more detailed images of celestial objects than can be obtained with any single telescope at these wavelengths.

After 12 years of development by a large number of engineers and astronomers in France, Germany, Austria, the Netherlands and at ESO, and following an extensive period of demanding work installing and testing this very complex instrument, initial observations have now confirmed that MATISSE is working as expected.

The initial MATISSE observations of the red supergiant star Betelgeuse, which is expected to explode as a supernova in the next thousand years, showed that it still has secrets to reveal. The new observations show evidence that the star appears to have a different size when seen at different wavelengths. Such data will allow astronomers to further study the huge star’s surroundings and how it is shedding material into space.

The principal investigator of MATISSE, Bruno Lopez (Observatoire de la Côte d’Azur (OCA), Nice, France), explains its unique power: “Single telescopes can achieve image sharpness that is limited by the size of their mirrors. To obtain even higher resolution, we combine — or interfere — the light from four different VLT telescopes. Doing this enables MATISSE to deliver the sharpest images of any telescope ever in the 3–13 μm wavelength range, where it will complement the James Webb Space Telescope’s future observations from space.

MATISSE will contribute to several fundamental research areas in astronomy, focusing in particular on the inner regions of discs around young stars where planets are forming, the study of stars at different stages of their lives, and the surroundings of supermassive black holes at the centres of galaxies. By looking at the inner regions of protoplanetary discs with MATISSE, astronomers hope to learn the origin of the various minerals contained in these discs — minerals that will later go on to form the solid cores of planets like the Earth. It will also be possible to study details of exotic objects in our Solar System, such as volcanoes on Io, and the atmospheres of giant exoplanets.

This image is a colourised version of the first MATISSE interferometric observations of the star Sirius, combining data from four Auxiliary Telescopes of the VLT. The colours represent the changing wavelengths of the data, with blue showing the shorter wavelengths and red the longer. The observations were made in the infrared, so these are not the colours that would be seen with the human eye. Credit: ESO/MATISSE consortium. source: ESO/MATISSE konzorcium

MATISSE is a four-way beam combiner, meaning it combines the light collected from up to four of the Unit Telescopes or up to four of the Auxiliary Telescopes that make up the VLTI, performing both spectroscopic and imaging observations. In doing so, MATISSE and the VLTI together possess the imaging power of a telescope up to 200 metres in diameter, capable of producing the most detailed images ever at mid-infrared wavelengths. Initial tests were made with the Auxiliary Telescopes, and further observations with the four VLT Unit Telescopes are planned during the next few months.

MATISSE’s first light marks a big step forward in the scope of current optical/infrared interferometers and will allow astronomers to obtain interferometric images with finer detail over a wider wavelength range than currently possible. MATISSE will also complement the instruments planned for ESO’s upcoming Extremely Large Telescope (ELT), in particular METIS (the Mid-infrared ELT Imager and Spectrograph). MATISSE will observe brighter objects than METIS, but with higher spatial resolution.

Infrared interferometry has a long tradition at Konkoly Observatory (Research Centre for Astronomy and Earth Sciences, Hungarian Academy of Sciences). Hungarian researchers have been using this technique since 2003 to study astronomical objects with the highest possible spatial resolution. This activity was expanded in 2011 with the Hungarian participation in the MATISSE project, which was in the planning phase at that time. The Hungarian technical contribution included thermal simulations for the heat load caused by motors operating at close to absolute zero temperature and the design and manufacturing of the calibration camera of an instrument unit. Hungarian engineers computed different parameters of the elements necessary for the safe movement of the instrument, which is important for ensuring that the mechanical stress it experiences during transportation does not exceed the limitations, which would cause damage. Researchers at Konkoly also participated in the definition and development of the instrument’s user software.

In recognition of the Hungarian efforts, Konkoly Observatory will have guaranteed telescope time to use MATISSE, and the astronomers plan to obtain an image of the protoplanetary disc around FU Orionis, a young star that showed a powerful outburst. In order to have first-hand experience on how to use the instrument, József Varga from Konkoly Observatory will travel to Paranal Observatory to participate in the commissioning of MATISSE.

Péter Ábrahám, research advisor at Konkoly Observatory and the leader of the Hungarian MATISSE project emphasizes that “the successful Hungarian contribution to MATISSE shows a good example for a synergy between high-tech instrument development and world-class scientific research using the most powerful astronomical instruments. I’m confident that this will lead to interesting new discoveries, and may even help Hungary’s future accession to the European Southern Observatory, the world’s most successful astronomical organizion.

Further information

This press release is based on the news article available at ESO’s web page:


Péter Ábrahám (Konkoly Observatory)
phone +36 1 391 9351

Ágnes Kóspál (Konkoly Observatory)
phone: +36 1 391 9338

György Mező (Konkoly Observatory)
phone: +36 1 3919346

Róbert Szabó (Konkoly Observatory)
phone: +36 1 3919367

József Varga (Konkoly Observatory)
phone: +36 1 3919358