[Astronomy seminar] Astronomy seminar Friday 27/9 10:30 FC61: Katja Poppenhäger

[Astronomy seminar announcements]

Astronomy seminar

Time & location: Friday September 27, 10:30 in FC61

Speaker: Katja Poppenhäger (AIP, Potsdam)

Title: Understanding the evolution of star-exoplanet systems

Abstract:
Stars and their exoplanets evolve together over billions of years, just 
like our own solar system.  Many known exoplanetary systems have planets 
orbiting their host stars at much closer distances than we observe in 
the solar system, with orbital periods of only a few days.  In such 
systems one  expects  the  star  and  its close-in  planet  to  
interact  through  tidal and magnetic forces, tying their evolution 
together.  These interactions can give us insights into fundamental 
properties of star- planet systems which are hard to constrain 
otherwise:  the time scale over which close-in planets spiral into the 
star, the evolution of stellar activity, and the amount of atmospheric 
evaporation and the habitability for all planets in a system with a 
close-in planet.  Gaia and other telescopes have now opened up new 
pathways to measure how stars and planets interact with each other.  I 
will present new approaches to test for planet-induced influences on 
stars through wide binary systems, motivate a new look at stellar 
magnetic activity measurements,  and discuss how planetary atmospheres 
can evaporate over the lifetime of exoplanets.

Also TODAY 23/9 @ 13:00: PhD Defence Anders Nyholm in FB42

4/10 (Fri) @ 10:30: Tim Dietrich (Amsterdam)
11/10 (Fri) @ 10:30: *POSTPONED TO 2020-02-07* John Airy (SU Science 
Education)
18/10 (Fri) @ 10:30: Marta Silva (Oslo ITA)
24-26/10 (Thu-Sat): Astronomdagarna


All welcome! Alexis Brandeker (Astronomy seminar organiser 2019)


On 2019-09-09 7:33 , Alexis Brandeker wrote:
> Astronomy seminar
>
> Time & location: Friday September 13, 10:30 in FC61
>
> Speaker: Carina Persson (Chalmers)
>
> Title: Exoplanet discovery and characterisation
>
> Abstract:
> Observations during the last decade have uncovered large populations 
> of exoplanets without any counterparts in our own planetary system. 
> This diversity has been one of the major discoveries. One of the most 
> powerful tools in the hunt for new exoplanets is dedicated space 
> mission surveys using the technique of ultra-high precision transit 
> photometry. This allows not only discoveries of new planets, but also 
> measurements of the radius relative to the host star and orbital 
> parameters. By combining the photometry from space missions with 
> ground-based radial velocity measurements, true planet masses and bulk 
> densities can be obtained. But although more than 4000 exoplanets have 
> been detected to date, mainly by the Kepler space telescope, far fewer 
> have been fully characterised and hence the composition and internal 
> structure for most exoplanets are unknown. Only a few tens of 
> Super-Earths have been securely identified. This paucity is related to 
> the faintness of the target stars and a new generation of spacecrafts 
> is therefore specifically targeting bright stars. NASA's TESS 
> spacecraft, launched in April 2018, is an all sky survey mission of 
> short period planets orbiting bright stars which will enable precise 
> follow-up observations. CHEOPS (Characterising Exoplanet Satellite), 
> to be launched 17 Dec 2019, is a European mission equipped with 
> ultra-high precision photometers. The targets will be bright stars 
> already known to host exoplanets and will be observed individually. 
> The European PLATO mission with a launch in 2026 is a next-generation 
> planet-hunter with an emphasis on rocky planets in the habitable zone 
> around solar-type stars. In this talk, I will give an overview of our 
> work at Chalmers and the collaboration with the international KESPRINT 
> consortium.
>
> Other upcoming activites:
>
> 18/9 (Wed) @ 10:00: PhD Defence Emanuel Gafton in FA31
> 20/9 (Fri) @ 10:30: [CANCELLED: John Miller (Oxford)]
> 23/9 (Mon) @ 13:00: PhD Defence Anders Nyholm in FB42
> 27/9 (Fri) @ 10:30: Katja Poppenhaeger (Potsdam)
> 4/10 (Fri) @ 10:30: Tim Dietrich (Amsterdam)
>
> All welcome! Alexis Brandeker (Astronomy seminar organiser 2019)
>