[Alumnos] Charla de Profesora invitada: Margit Paparo (Hungria)

[Secretaria de Postgrado FCAG]

Invitación:

La Prof. Margit Paparo del MTA, CSFK, Konkoly Observatory Budapest (Hungary), 
brindará una charla titulada "CoRoT - Closer to the non-radial and non-linear 
effects of the pulsation". La misma tendrá lugar el día jueves 27 de marzo a 
las 14:00 hs en el salón Meridiano.

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CoRoT - Closer to the non-radial and non-linear effects of the pulsation
Margit Paparo
MTA, CSFK, Konkoly Observatory
Budapest, Hungary

Abstract:

The space data basically changed the aspect of the variable star research. With 
the space projects (MOST, CoRoT, Kepler) we had good hope to solve some 
long-standing problems. The space data really increased our knowledge but 
created more and more questions that we have to solve. The Hungarian 
Asteroseismology Group (HAG) has a project working on CoRoT data supported by 
the European Space Agency (ESA). The group does not have a permenent team, it 
changes from time to time. The activity of HAG reflects the interest of the 
actual contributors from RR Lyrae to main sequence stars, from observational to 
theoretical approaches. I give a cross-section of the activity and results of 
HAG:

- The fine structure of the amplitude and phase modulation, the period 
doubling caused by 9:2 resonance are the newest results on the Blazhko 
type RR Lyrae stars (non-linear effects). Non-radial modes are clearly 
shown in these, traditionally pure radial pulsators (RRc). Using the 
formalizm of telecommunication for Blazhko type RR Lyrae stars presents a 
new theoretical approach to separate the physical processes as periodic, 
quasi-periodic, stochastic or chaotic.

- Light variations in colour channels were used to derive differential 
rotation in an active star and separate a Beta Ceph pulsation in a closely 
spaced star.

- Main sequence stars, both Delta Scuti and Gamma Doradus stars, pulsating 
in the non-asymptotic regime, suffer from the lack of mode identification. 
The increased number of excited modes and the lack of unlimited observing 
time for many targets inspire to find new approaches of the mode 
identification based only on the well-established observables, the 
frequency spacing and period ratios.

- We discovered the first CoRoT heart-beat binary, where the components 
have similar mass, similar abundances, slightly different temperature, 
however one of them shows Delta Scuti pulsation. In one binary system, we 
are faced with the long-standing question: why some of the stars pulsate 
in the instability strip but the othes do not pulsate in the middle of the 
instability stip. We definitely need an advanced theoretical approach for 
answering the old/new questions.

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Dr. Alejandro H. Córsico
Secretario de Posgrado
Facultad de Ciencias Astronómicas y Geofísicas
Universidad Nacional de La Plata
http://www.fcaglp.unlp.edu.ar/area-docente/posgrado/posgrado
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