Heliophysics

The heliosphere is a giant circumsolar plasma cocoon with a diameter of the order of several hundred astronomical units. It shields the planets from a direct contact with the interstellar medium by deflecting the interstellar plasma flow, by efficiently ionizing neutral gas components and by reducing the flux of cosmic rays. The structure of the heliosphere is changing in time due to solar activity and to a changing interstellar environment.

Contemporary research considers the Sun and the heliosphere as an integrated system, whose parts should be considered separately but are tightly interconnected by, for example, the solar/heliospheric magnetic field.

An understanding of the heliosphere is not only desirable in view of its role as a shield protecting life on Earth but also as natural plasmaphysical laboratory in which many fundamental plasma physical process, like turbulent diffusion, stochastic acceleration or nonthermal heating by plasma waves, can be studied. Narrowing the focus from the global to the inner heliosphere leads directly to the field of Space Weather, i.e. the influence of the Sun on the interplanetary medium, in general, and the terrestrial magnetosphere and atmosphere, in particular.

Widening the focus enables one to consider the heliosphere as an example for astrospheres around other stars and brings one to consider the nature of the interstellar medium including the transport of cosmic rays within.

Sketch of the heliosphere and its constituents

Artist’s conception of the solar magnetic field, with field lines shown as blue ribbons.

Hubble telescope image showing an illuminated bow shock at another star. Credits: NASA, ESA, and The Hubble Heritage Team (STScI/AURA).

Group seminar

Tue 14-16, NB 7/67

Day Lecturer Title
06.05.2025Rudi GaelzerTba
13.05.2025Klaus SchererAstrospheres: Input parameter and GCR fluxes
20.05.2025Sarah UthmannOn ab-initio CR modulation modelling
27.05.2025Ingrid MannInterstellar dust in the heliosphere
03.06.2025--No seminar [visit to Eindhoven]
10.06.2025--No seminar [Pfingstwoche]
17.06.2025Jens KleimannA new class of shape models for the magnetized flow around blunt objects
24.06.2025Shaaban M. ShaabanTba
01.07.2025Lukas WestrichSolar wind models with local heating
08.07.2025Waleed MoslemTba

Lecture notes