[institut] [phys4phys] Naucno-strucni skup AOB (15. decembar)

[Ivana]

Koleginice i kolege,

u biblioteci Astronomske opservatorije bice odrzan Naucno-strucni skup u 
sredu 15. decembra sa pocetkom u 13 h. Link za pracenje predavanja putem 
Webex-a, poslacemo vam naknadno. Predavanje ce biti snimljeno i 
postavljeno na zvanicni YouTube kanal Astronomske opservatorije u 
Beogradu (https://www.youtube.com/AstronomskaOpservatorijaBeograd).

Izlagac: László Molnár, Konkoly Observatory, ELKH CSFK, Budapest

Naslov predavanja: Hiccuping and barfing red giants, and how to model 
them

Apstrakt: Red giant and supergiant stars have many processes going on in 
them, from shell burning and thermal pulses to stellar pulsation an dust 
creation that can be difficult to interpret and model correctly. Here I 
present two cases where we used the MESA and GYRE software packages to 
model the behavior and evolutionary states of such stars. The first, T 
UMi used to be a Mira star whose pulsation period started to shorten 
drastically in the last few decades. We reproduced this behavior in the 
models and matched the observed characteristics, confirming that the 
star started a thermal pulse (He-shell flash) a few decades ago. We also 
predict that it might reach minimum radius and period within our 
lifetimes. The other star we studied is the red supergiant Betelgeuse, 
which recently went through an unusually faint phase. Not only did we 
identify a new pulsation mode in the star, we were also able to revise 
the physical size of the star through the models. Since Betelgeuse is 
close enough and large enough, its angular diameter can be measured: 
with that in hand we were able to calculate a new distance to the star 
based on seismic inferences alone, independent of previous measurements.



Dobro dosli!


  Ivana Milić Žitnik
  Naučni saradnik
  Astronomska opservatorija
  Volgina 7, 11000 Beograd
  Republika Srbija
  00381 11 3089069
  00381 62 357067