Seminarium: Magnetic fields of binary stars

  • Datum: –15.00
  • Plats: Zoom https://uu-se.zoom.us/j/64257004440
  • Föreläsare: Oleg Kochukhov & Axel Hahlin
  • Kontaktperson: Sofia Ramstedt
  • Seminarium

Magnetic fields and related surface activity phenomena - spots, flares, cyclic coronal and chromospheric emission - play a central role in the physics of cool stars. These effects are also understood to be crucial in governing the interaction of stars and their planets. In particular, host-star activity influences atmospheric and surface characteristics, and ultimately habitability, of terrestrial planets. Despite its importance, magnetism is one of the least explored aspects of stellar physics, from theoretical and observational sides alike. We still do not know how exactly the Sun generates its magnetic field, why this process is cyclic and how its characteristics change on long time scales. The only sensible observational approach to addressing these questions and test competing theories of stellar magnetism is to collect detailed information on the strength and topologies of magnetic fields in many stars similar and different from the Sun. Binary stars, especially those in eclipsing systems, are privileged laboratories for stellar magnetism studies thanks to several additional constraints that such systems can provide compared to isolated stars. In this presentation we will discuss ongoing projects aimed at studying magnetic fields of cool binaries. We will focus specifically on the eclipsing binary system UV Psc, for which we have carried out a detailed investigation of both large- and small-scale magnetic fields in both components. Future plans for analysis of other binary systems will be also discussed.

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We will run with the following setup:
- The zoom meeting will open at 13.45 so that you can log on and try it out.
- Participants should mute their microphones unless they have a question.
- Questions are allowed during the talk. Just raise your hand in the zoom app.
- After the talk has finished, unmute for applause.
- If possible, keep your video on during the full seminar so that the speaker gets visual feedback while talking.
- Questions after the talk will be administered as follows; raise your hand in the app and Sofia will chair and give the word.

- Finally, after the talk and question sessions are finished, the meeting will remain open for an informal ”bring-your-own-fika” if you want to hang around and chat with your colleagues and the speaker. Since this is a 4-month seminar, the faculty will again meet in a breakout room.