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SUMMARY:The historical color change of Betelgeuse as constraint for theore
 tical evolutionary models
DTSTART:20261124T103000Z
DTEND:20261124T113000Z
DTSTAMP:20261109T001900Z
UID:indico-event-1966@indico.dfa.unipd.it
CONTACT:elisabetta.rigliaco@inaf.it
DESCRIPTION:Speakers: Ralph Neuhäuser (University Jena)\n\n\n\nIt is diff
 icult to determine the distance of the red super-giant Betelgeuse precisel
 y\, because its angular size on sky is larger than its parallax -distances
  from ca. 150 to 200 pc are discussed. The resulting large luminosity rang
 e yields a large range in mass (ca. 8 to 20 solar masses) and in remaining
  life-time until the supernova - both from theoretical evolutionary model 
 tracks\, e.g. Parsec models.We found two independent\, ca. 2000 year old h
 istorical observations\, which describe Betelgeuse as "yellow" (China) and
  compare it in color to Saturn (Rome) with B-V=1.09 \\pm 0.16 mag\; today\
 , Betelgesue has B-V=1.78 mag. Such a rapid color change is consistent wit
 h models\, if Betelgeuse has eight solar masses and has just crossed of th
 e Hertzsprung gap in the last two millennia (e.g. MESA and Parsec models).
  In turn\, the historical color change can be used to constrain evolutiona
 ry model tracks further and to determine the star's parameters more precis
 ely (e.g. mass\, chemical composition\, rotation).We are currently pursuin
 g such a project with the Parsec team. Most recently\, a very faint low-ma
 ss companion candidate has been detected near Betelgeuse. While such a clo
 se companion might be usable to measure the mass of Betelgeuse dynamically
  within a few years\, we will also discuss\, whether a nearby companion ca
 n affect the outer atmosphere of Betelgeuse and\, hence\, its color evolut
 ion.\n \n\nJoin Zoom Meeting  \n \n\n\nhttps://unipd.zoom.us/j/58283407
 60?pwd=6jmmfQkNz1qXnnOzaEWzo9kuEunbhb.1 \n \nMeeting ID: 582 834 0760Pa
 sscode: Npsvx4\n\n\n\n\nhttps://indico.dfa.unipd.it/event/1966/
LOCATION:Sala Jappelli (Osservatorio astronomico di Padova)
URL:https://indico.dfa.unipd.it/event/1966/
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