Dissertation defense
Student: Yasmmin Ferreira Tamburus
Program: Astronomy
Title: "Interaction between winds from young stars and planetary magnetospheres"
Advisor: Profa. Dra. Vera Jatenco Silva Pereira
Judging Committee
- Profa. Dra. Vera Jatenco Silva Pereira - IAG/USP (Orientadora e Presidente da banca)
- Profa. Dra. Jane Cristina Gregorio Hetem - IAG/USP
- Dra. Thais dos Santos Silva - Pos-Doc / IAG
- Prof. Dr. Iberê Luiz Caldas - IF/USP
Abstract
Evolved T Tauri stars exhibit strong stellar winds and surface magnetic fields of around kG. Previous studies have shown that the damping of Alfvén waves, generated by turbulent motions at the base of the stellar wind, can explain the observed velocity of these winds. With the growing interest in the search for rocky exoplanets with Earth-like dimensions, it is crucial to deepen our understanding of the interaction between the stellar wind and the planetary magnetosphere. This interaction can act as a protective barrier, mitigating atmospheric erosion caused by the wind. In this project, we investigate how the magnetized stellar wind, guided by Alfvén waves, interacts with the planetary magnetosphere, assessing the impacts of this interaction on the possible reduction or loss of the planetary atmosphere and its implications for the planet's habitability and compared it with a model for the non-magnetized solar wind. To do this, we used the Parker (1958) and Jatenco-Pereira & Opher (1989) models to determine the velocity profile of the stellar wind. We studied whether an Earth-like planet in the habitable zone of these stars would be able to sustain their atmospheres. In this way, we concluded that only a few planets could have magnetospheres large enough to protect their atmospheres. In addition, we found that magnetic pressure is important when calculating magnetospheric sizes and cannot be neglected.
Keywords: Young star winds, planetary magnetospheres, Alfvén waves