| dc.contributor.advisor | Solanki, Sami Prof. Dr. | |
| dc.contributor.author | Panja, Mayukh | |
| dc.date.accessioned | 2021-08-09T11:11:51Z | |
| dc.date.available | 2021-08-15T00:50:03Z | |
| dc.date.issued | 2021-08-09 | |
| dc.identifier.uri | http://hdl.handle.net/21.11130/00-1735-0000-0008-58D4-6 | |
| dc.identifier.uri | http://dx.doi.org/10.53846/goediss-8773 | |
| dc.language.iso | eng | de |
| dc.rights.uri | http://creativecommons.org/licenses/by-nc-nd/4.0/ | |
| dc.subject.ddc | 530 | de |
| dc.title | Realistic MHD simulations of spots on cool main-sequence stars | de |
| dc.type | doctoralThesis | de |
| dc.contributor.referee | Solanki, Sami Prof. Dr. | |
| dc.date.examination | 2020-12-11 | |
| dc.subject.gok | Physik (PPN621336750) | de |
| dc.description.abstracteng | Sunspots are cool, dark features on the solar surface consisting of
two distinct parts - the inner dark umbra and its surrounding
brighter, filamentary penumbra. Strong, nearly vertical magnetic
fields found in the umbra locally suppress overturning convective
motion while the more inclined fields of the penumbra support the
outward Evershed flow. The fine structure of sunspots has been
studied in much detail with the help of both ground and
space-based telescopes. Our knowledge about starspots, in
comparison, is very limited. This is mainly because other stellar
surfaces are at best poorly resolved. The fine structure of starspots
is still unknown and how similar, or dissimilar, they are to spots on
the Sun remains to be answered. In this thesis, I have attempted to
make headway into these unsolved astrophysical problems through
box-in-a-star
realistic
radiative
magnetohydrodynamic
simulations. Further, I synthesized spectral lines from the
simulated starspot atmospheres. This allowed me to combine
synthetic line profiles of umbrae, penumbrae, and quiet star
regions calculated at various viewing angles to create disk
integrated line profiles which I used to estimate the effects of
spots on stellar radial velocity. | de |
| dc.contributor.coReferee | Reiners, Ansgar Prof. Dr. | |
| dc.contributor.thirdReferee | Rempel, Matthias Dieter Dr. | |
| dc.subject.eng | sunspots | de |
| dc.subject.eng | starspots | de |
| dc.subject.eng | stellar physics | de |
| dc.identifier.urn | urn:nbn:de:gbv:7-21.11130/00-1735-0000-0008-58D4-6-8 | |
| dc.affiliation.institute | Fakultät für Physik | de |
| dc.description.embargoed | 2021-08-15 | |
| dc.identifier.ppn | 1765981859 | |