Sunrise III flies, IRSOL accompanies it

On Wednesday 10 July 2024, the balloon-borne solar telescope Sunrise III was launched into the stratosphere from Kiruna, Sweden. It is currently flying towards Canada and observes the Sun around the clock for several days making use of the continuous sunshine during the arctic summer. Meanwhile, the IRSOL (Istituto ricerche solari Aldo e Cele Daccò) is  measuring solar magnetic fields in coordination with Sunrise III.

The 1-metre Sunrise telescope developed by an international consortium under the leadership of the Max-Planck institute for Solar research, MPS, Göttingen, Germany, has already flown in 2009 and 2013, at different phases of the solar cycle, and has so far led to the publication of more than 100 papers in scientific journals. Sunrise III instruments are  the ultraviolet and infrared spectropolarimeters and optical imaging magnetograph. The high spatial resolution images and data collected during the mission will be used to reconstruct the turbulent convective motions in the solar photosphere, to understand why the chromosphere is much hotter than the underlying photosphere, and to study the influence of solar activity variability on the Earth's stratosphere and thus on our planet's climate.  This will be achieved by comparing the data with numerical models and simulations.  A fundamental task is  not only to satisfy the natural human curiosity about our nearest star, but also to be able to predict its potentially most dangerous phenomena, such as powerful explosions leading to geomagnetic storms.

While Sunrise III flies to Canada, its team decides which scientific tasks are to be implemented and which solar regions and phenomena are to be observed. From Locarno, the IRSOL team, with its own solar telescope and the world most precise solar spectropolarimeter ZIMPOL, is carrying out coordinated observations of the same solar targets but following its own previously planned programme, which is complementary to that of Sunrise III. Also, the solar radio-antenna e-CALLISTO at IRSOL continuously records solar radio bursts, as a part of a worldwide network of about 200 antennas. The IRSOL and Sunrise III data will be jointly analysed by the two teams, and the results will be compared with the models and simulations developed at IRSOL, a field of research in which IRSOL is also at the forefront. The Locarno Institute, affiliated to USI, contributes therefore its expertise and unique data to a broad international research programme in which many other groups and institutes participate.