Cristin-prosjekt-ID: 358906
Sist endret: 22. september 2014, 14:47

Cristin-prosjekt-ID: 358906
Sist endret: 22. september 2014, 14:47
Prosjekt

Magnetic Activity of the Atmospheres of M-type Dwarf Stars

prosjektleder

Sven Wedemeyer
ved Institutt for teoretisk astrofysikk ved Universitetet i Oslo

prosjekteier / koordinerende forskningsansvarlig enhet

  • Universitetet i Oslo

Klassifisering

Vitenskapsdisipliner

Astrofysikk, astronomi

Tidsramme

Avsluttet
Start: 1. oktober 2011 Slutt: 30. september 2014

Beskrivelse Beskrivelse

Tittel

Magnetic Activity of the Atmospheres of M-type Dwarf Stars

Sammendrag

Dwarf stars of spectral type M, shortly referred to as “M-dwarfs”, are the most frequent stars in the universe. They are therefore of large interest for our understanding of stars, their role as host stars of extrasolar planets and for a wide range of topics including the chemical composition and evolution of the universe. Unfortunately, many properties of the atmospheres of these small and faint stars are poorly known. It is still under debate whether a global dynamo in the interior or rather a local dynamo at the surface generates the magnetic fields observed in M-dwarfs. The resulting magnetic activity is observed in form of radiation emitted from the stellar chromospheres.Space telescopes like Kepler and the future GAIA provide high-quality data, which will allow for characterizing the properties of M-dwarf atmospheres and their activity. A systematic set of realistic theoretical models is essential for a meaningful interpretation of the observations but does not exist so far.The primary aim of this project is therefore the production of a small grid of 3-D models and synthetic spectra, which can be compared to data from ground-based and space-borne observatories.

Vitenskapelig sammendrag

Dwarf stars of spectral type M, shortly referred to as “M-dwarfs”, are the most frequent stars in the universe. They are therefore of large interest for our understanding of stars, their role as host stars of extrasolar planets and for a wide range of topics including the chemical composition and evolution of the universe. Unfortunately, many properties of the atmospheres of these small and faint stars are poorly known. It is still under debate whether a global dynamo in the interior or rather a local dynamo at the surface generates the magnetic fields observed in M-dwarfs. The resulting magnetic activity is observed in form of radiation emitted from the stellar chromospheres.

Space telescopes like Kepler and the future GAIA provide high-quality data, which will allow for characterizing the properties of M-dwarf atmospheres and their activity. A systematic set of realistic theoretical models is essential for a meaningful interpretation of the observations but does not exist so far.

The primary aim of this project is therefore the production of a small grid of 3-D models and synthetic spectra, which can be compared to data from ground-based and space-borne observatories.

Metode

- time-dependent numerical simulations (3-D radiation magnetohydrodynamics in a local setup)
- radiative transfer calculations for the production of stellar spectra and intensity maps
- detailed comparison to observations

Utstyr

high-performance computing

prosjektdeltakere

prosjektleder
Aktiv cristin-person

Sven Wedemeyer

  • Tilknyttet:
    Prosjektleder
    ved Institutt for teoretisk astrofysikk ved Universitetet i Oslo
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