Photovoltaic orbiter sends high-resolution images of the sun’s surface and reveals new details

The European Space Agency’s (ESA) Photovoltaic Orbiter spacecraft has provided the most detailed images of the solar surface to date. These images, taken in March 2023 from a distance of approximately 74 million kilometers, were published on November 20. They provide unprecedented information about the photosphere, the layer of the Sun responsible for emitting light. The photographs show complex dynamic structures of granules (plasma cells about 1000 kilometers wide) formed as a result of convection, when hot plasma rises and cooler plasma descends.

Analysis of sunspot activity and magnetic fields

The images show sunspots as cooler, darker regions of the photosphere where intense magnetic fields disrupt the movement of plasma. The Polarimetric and Helioseismic Imager (PHI) on board the Photovoltaic Orbiter created detailed maps of these magnetic fields, identifying their significant concentration in sunspot regions. According to Daniel Müller, ESA’s Photovoltaic Orbiter project scientist, these observations are essential to understanding the dynamic processes on the Sun. Sunspots appear cooler because magnetic forces limit regular convection, causing surface temperatures to drop.

New data on solar rotation and winds

A velocity map known as a tachogram was also published, which illustrates the speed and direction of material moving on the surface of the Sun. The blue regions represent the plasma moving towards the spacecraft, and the red regions show the receding plasma, showing the dynamics of the Sun’s rotation. Additionally, magnetic fields in sunspot regions have been observed to further alter surface materials.

The Sun’s outer atmosphere, the corona, was imaged using the spacecraft’s Excessive Ultraviolet Imager. Loops of plasma protruding from the Sun, visible in these images, are associated with sunspots and contribute to the formation of photovoltaic wind. This solar wind, when it reaches Earth, usually causes auroras.

Future missions to explore the solar poles

The photovoltaic orbiter, launched in 2020 as a joint mission with NASA, aims to capture unprecedented views of the solar poles. These observations are planned for 2025, when the spacecraft’s orbit will be aligned for a direct perspective. Recent image processing involved assembling 25 smaller images, a complex process that is expected to be sped up in future releases.