Differential Rotation in Sun-like Stars from Surface Variability and Asteroseismology

1. Front Matter

   Pages i-xvi

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2. Introduction

   • Martin Bo Nielsen

   Pages 1-35

3. Paper I—Rotation Periods of 12,000 Main-Sequence Kepler Stars

   • Martin Bo Nielsen

   Pages 37-49

4. Paper II—Rotational Splitting as a Function of Mode Frequency for Six Sun-like Stars

   • Martin Bo Nielsen

   Pages 51-62

5. Paper III—Constraining Differential Rotation of Sun-like Stars from Asteroseismic and Starspot Rotation Periods

   • Martin Bo Nielsen

   Pages 63-78

6. Discussion: Constraining Interior Rotational Shear

   • Martin Bo Nielsen

   Pages 79-89

7. Back Matter

   Pages 91-101

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In his PhD dissertation Martin Bo Nielsen performs observational studies of rotation in stars like the Sun. The interior rotation in stars is thought to be one of the driving mechanisms of stellar magnetic activity, but until now this mechanism was unconstrained by observational data.


NASA’s Kepler space mission provides high-precision observations of Sun-like stars which allow rotation to be inferred using two independent methods: asteroseismology measures the rotation of the stellar interior, while the brightness variability caused by features on the stellar surface trace the rotation of its outermost layers. By combining these two techniques Martin Bo Nielsen was able to place upper limits on the variation of rotation with depth in five Sun-like stars. These results suggest that the interior of other Sun-like stars also rotate in much the same way as our own Sun.

• Stellar Rotation
• Asteroseismology
• Differential Rotation
• Sun-like Stars
• Photometric Variability
• Kepler Mission
• Starspots

• Institut für Astrophysik, Georg-August-Universität, Göttingen, Germany

  Martin Bo Nielsen

Martin Bo Nielsen received his B.Sc and M.Sc degrees from Aarhus University in Denmark, during which he spent one year as a student support astronomer at the Nordic Optical Telescope on La Palma, Spain. This was followed by a PhD on the topic of differential rotation in Sun-like stars, at Georg-August-Universität in Göttingen, under the supervision of Prof. Laurent Gizon and Dr. Hannah Schunker.     

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