Sunrise (telescope)
Sunrise is a balloon-borne astronomical observatory designed to observe the Sun's photosphere and chromosphere. It carries a 1-metre solar telescope that redirects infrared, visible, and ultraviolet radiation from the Sun to a suite of scientific instruments. Sunrise is managed by the Max Planck Institute for Solar System Research.
Sunrise completed three successful science flights between 2009 and 2024. Sunrise I and II, flown in June 2009 and June 2013, respectively, both carried an imager and magnetograph. Sunrise III, flown in July 2024, carried updated instrumentation including two slit-based spectropolarimeters and a new magnetograph. All three flights were launched from the Esrange Space Center near Kiruna, Sweden and around the Northern-Hemisphere summer solstice when the polar day allowed for continuous observation of the Sun.
The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and magnetic fields at a resolution of around 100 km in the quiet Sun.
Overview
The strong absorption of UV radiation by the Earth's atmosphere makes it challenging to carry out ground-based observations at these wavelengths. A balloon mission reaching altitudes of above 30 km benefits from a reduction of UV absorption by 99%, making engineering solutions for the telescope easier. The launch site was in the arctic region to make uninterrupted observation of the Sun over several days possible. The telescope has a 1 metre primary mirror that directs the 1 kW of solar radiation to the first focal point where 99% of the radiation is reflected out of the telescope, the remaining light is transferred into several instruments.The one metre diameter primary mirror is made from a glass ceramic zerodur, it is the central part of the gondola of nearly 2 tons. Solar panels of 1.5 kW output power are used to power the onboard equipment and a hard disk array of 2 x 2.4 Terabyte is used to store the data during flight.
Instruments
- CWS, Correlating Wavefront Sensor is a CCD camera with 1 kHz read-outs responsible generate the images necessary for image stabilization and proper alignment.
- SUFI, Sunrise Filter Imager observes the sun in five distinct wavelengths 214, 300, 312, 388 and 397 nm, on a 2048 x 2048 pixel CCD, through a filter wheel.
- IMaX, Imaging Magnetograph eXperiment observes the Zeeman splitting of the iron line around 525 nm. The observed field of view is 50 x 50 arcseconds.