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The James Webb Space Telescope on its way to its observation site (L2)

After many delays, the James Webb Space Telescope (JWST) is finally launched on Christmas Day 2021. The Department of Astronomy, Stockholm University, has the largest participation in projects with JWST from the Swedish side.

JWST packas upp i Franska Guyana. Bild: ESA/CNES/Arianespace

JWST was built by the US space agency, NASA, in collaboration with the European, ESA, and the Canadian. JWST is the sequel to the very successful Hubble Space Telescope (HST), but JWST is larger and optimized for infrared (IR) wavelengths. This means that JWST will be able to look further back in time, to the childhood of the universe, see through and study the dust that obscures observations in optical wavelengths, and observe objects that shine brightest in IR, e.g. exoplanets. JWST is on its way to Lagrangepunkten L2, about 1.5 million km from Earth.
Sweden has contributed to the design of the MIRI instrument, which was built jointly by a European-American consortium. The initiator of the Swedish participation was Göran Olofsson, who was originally a Swedish co-PI, and the Swedish co-I’s were Claes Fransson, Kay Justtanont and Göran Östlin (all then at the Department of Astronomy, SU). Sweden's hardware contribution was the design of optical filters for imaging in selected wavelength ranges, and was funded by SNSA and KAW. At Göran Olofsson's retirement, Kay Justtanont (who had then moved to Chalmers) took over as Swedish co-PI, and since 2020 Göran Östlin is Swedish co-PI. All of these researchers are involved in several of the 'guaranteed time observations' (GTO) that the European consortium receives as compensation for its work in developing MIRI. These include studies of distant galaxies, nearby galaxies (especially the extremely metal-poor dwarf galaxy IZw18), supernova 1987A, protoplanetary disks and the atmospheres of a number of exoplanets. Researchers Arjan Bik and Jens Melinder (Department of Astronomy, SU) will also be involved in the studies of distant galaxies.
Most of the time at JWST is allocated to projects in open scientific competition. It can be mentioned that three Swedish researchers, and all at the Department of Astronomy at SU, were given time as main applicants in the first application round: Angela Adamo (whose project will investigate the formation of star clusters in nearby galaxies), Alexis Brandeker (studies of the atmosphere of the exoplanet 55 Cancri ), and Emil Rivera-Thorsen (study of "the Sunburst arc", a distant galaxy magnified by a gravitational lens).
In addition to the above-mentioned researchers (several of whom are also involved in other approved projects), another eight people participate in the Department of Astronomy (Lorenza Della Bruna, Matthew Hayes, Markus Janson, Anders Jerkstrand, Peter Lundqvist, Matteo Messa, Mattia Sirressi, Christopher Usher), and a researcher at SU physics (Joel Johansson) and one at KTH physics (Josefin Larsson). Many of these are also active at the Oskar Klein Center. In addition, researchers from Uppsala and Chalmers participate in several approved projects with JWST.
There is thus a strong involvement of Swedish researchers, not least from SU, in projects with JWST. In total, at least 25 researchers affiliated with Swedish universities are involved in the first round of observations at JWST, which gives hope that the telescope can be a great success for Swedish astronomical research!