The outer atmosphere of the Sun, the corona, is a unique plasma laboratory. It provides key insights into fundamental universal processes (e.g. magnetic reconnection and particle acceleration). Yet, the very existence of the corona in itself is not well understood. It is composed of million Kelvin hot plasma trapped by magnetic fields, and overlies the much cooler 6000 K photosphere, the visible surface of the Sun. How do magnetic fields regulate mass and energy transport from the cool photosphere to sustain the overlying hot corona? This is a long-standing problem in astrophysics, which lacks a comprehensive explanation. The missing link in this puzzle is an observationally validated framework of how the corona is magnetically coupled to the photosphere.
The newly established research group ORIGIN, funded by the European Union, is geared toward tackling this challenging problem of developing a framework for coronal heating by probing the elusive photosphere-corona connection and comprehensively testing the importance of different magnetic processes in the heating of the outer solar atmosphere. The project will combine new and exciting data from the Extreme Ultraviolet Imager (EUI) and the Polarimetric and Helioseismic Imager (PHI), two of the remote-sensing instruments on the ESA-led Solar Orbiter space mission, to study how magnetic fields drive the hot solar corona.
Further reading:
1.
L. P. Chitta, H. Peter, S. K. Solanki, P. Barthol, A. Gandorfer, L. Gizon, J. Hirzberger, T. L. Riethmüller, M. van Noort, J. Blanco Rodríguez, J. C. Del Toro Iniesta, D. Orozco Suárez, W. Schmidt, V. Martínez Pillet, and M. Knölker, "Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields," Astrophysical Journal, Suppl. Ser. 229, 4 (2017).
E. R. Priest, L. P. Chitta, and P. Syntelis, "A Cancellation Nanoflare Model for Solar Chromospheric and Coronal Heating," The Astrophysical Journal Letters 862 (2), L24 (2018).
L. P. Chitta, Hardi Peter, and Sami K. Solanki, "Nature of the energy source powering solar coronal loops driven by nanoflares," Astronomy and Astrophysics 615, L9 (2018).
L. P. Chitta, A. R. C. Sukarmadji, L. Rouppe van der Voort, and Hardi Peter, "Energetics of magnetic transients in a solar active region plage," Astronomy and Astrophysics 623, A176 (2019).
Solar coronal structures observed with EUI. The left panel shows a high-resolution view of ~1 MK coronal loops in an active region. The right panel is a zoom into the south pole of the Sun, showing numerous megameter-scale plasma jets. These data were acquired during the first science perihelion of Solar Orbiter during March-April 2022.
Solar coronal structures observed with EUI. The left panel shows a high-resolution view of ~1 MK coronal loops in an active region. The right panel is a zoom into the south pole of the Sun, showing numerous megameter-scale plasma jets. These data were acquired during the first science perihelion of Solar Orbiter during March-April 2022.
Solar coronal structures observed with EUI. The left panel shows a high-resolution view of ~1 MK coronal loops in an active region. The right panel is a zoom into the south pole of the Sun, showing numerous megameter-scale plasma jets. These data were acquired during the first science perihelion of Solar Orbiter during March-April 2022.
Solar coronal structures observed with EUI. The left panel shows a high-resolution view of ~1 MK coronal loops in an active region. The right panel is a zoom into the south pole of the Sun, showing numerous megameter-scale plasma jets. These data were acquired during the first science perihelion of Solar Orbiter during March-April 2022.
Analyzing the high spatial resolution solar Ca II H and K emission data obtained by the SUNRISE mission and building a model of other stars more active than the Sun
The magnetic field in the solar atmosphere exceeds the geomagnetic field strength by four orders of magnitude. It greatly influences the processes of energy transport within the solar atmosphere, and dominates the morphology of the solar chromosphere and corona. Kinetic energy from convective motions in the Sun can be efficiently stored in magnetic fields and subsequently released - to heat the solar corona to several million degrees or to blast off coronal mass ejections.
First Light for Sunrise III: the first tests with real sunlight were successful. The balloon-borne solar observatory should be ready for launch at the end of May.
First icy cold, then midnight sun: at the Arctic Circle, the team will prepare the next flight of the balloon-borne solar observatory - and hopes for solar fireworks.
Astronomical teamwork: By combining data from Solar Orbiter and SDO, a group of researchers has unambiguously determined the magnetic field at the solar surface.
