Interstellar Dust Inside and Outside the Heliosphere

• Applicant: Privatdozent Dr. Harald Krüger
• Subject Area: Astrophysics and Astronomy
• Term: from 2009 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 86649323

During the last two decades, spacecraft-based in-situ dust measurements have shown that a continuous flow of micron-sized dust grains of interstellar origin sweeps through our solar system. Together with the interstellar gas flow, they are material from the Local Interstellar Cloud (LIC), tracing the physical conditions in the LIC. In the inner solar system the interstellar dust stream is altered by the solar radiation pressure force, gravitational focussing and interaction of charged grains with the time-varying interplanetary magnetic field (IMF).We propose to perform numerical simulations of the grain dynamics in the heliosphere and to analyse existing spacecraft in-situ dust data. Our goals are i) to identify the origin of a presently unexplained 30 shift in the impact direction of interstellar grains w.r.t. the interstellar gas direction observed in 2005/06; ii) to constrain the grain interaction with the time-varying solar wind driven IMF, in particular for the first time during solar maximum conditions of the IMF; iii) to determine the true size distribution of interstellar dust grains in the LIC; iv) to improve existing constraints on the physical conditions in the LIC, including the dust-to-gas mass ratio.

• DFG Programme: Research Grants