Hvert år inviterer Institutt for teoretisk astrofysikk en ledende internasjonal astrofysiker for å holde Rosselandforelesningen, til ære for Norges mest fremtredende astronom, professor Svein Rosseland (1894–1985).
Årets foreleser vil være professor Göran Scharmer fra Stockholms Universitet, direktør for Institutt for solfysikk ved Kungliga vetenskapsakademien. Tittel på foredraget er "Sunspots".
Rosselandforelesningen finner sted tirsdag 5. april kl. 11.15 i Store fysiske auditorium på Blindern.
Professor Göran Scharmer, Stockholm University, Director of the Institute for Solar Physics of the Royal Swedish Academy of Sciences: "Sunspots"
Abstract
Sunspots were first observed systematically in China well over 2000 years ago, but it was with the invention of the telescope 500 years ago that systematic scientific observations truly started, marking the beginning of solar physics and astrophysics as a whole. We might think that 500+ years of observations are enough and that by now we should know everything there is to know about sunspots, but understanding sunspots actually pose several of the most difficult challenges in astrophysics. The visible solar surface corresponds to the radiatively cooling layer of the solar interior. This strongly contributes to shaping the many complex and beautiful structures we observe, but also presents enormous challenge for theoretical models. Added to this is the presence of magnetic fields, counter intuitively appearing in concentrated forms, such as sunspots. Some of their outstanding properties, such as the strong outward sunspot winds, were discovered over 100 years ago, but have not been understood until just recently. How sunspots transport their energy to the surface is still a battle between theoreticians, but with a winner in sight. Other puzzles, such as why the Sun has sunspots at all, how they form and why their number changes in periods of 11 years, still awaits satisfactory explanations through self-consistent simulations.
About the Rosseland Lecture
To honor the memory of Norway's most prominent astrophysicist, Professor Svein Rosseland, the Institute of Theoretical Astrophysics every year invites a leading international astrophysicist to hold the Rosseland lecture on a date close to Rosselands birthday.