Naslov
Circumstellar dust around the symbiotic Mira RR Tel

Autori
Jurkić, Tomislav ; Kotnik-Karuza, Dubravka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Abstract book / Anja C. Andersen, Isabelle Cherchneff, Darach Watson - Ženeva, 2014

Skup
European Week of Astronomy and Space Science

Mjesto i datum
Ženeva, Švicarska, 30.06.2014. - 04.07.2014

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
binaries: symbiotic; circumstellar matter; radiative transfer; stars: AGB and post-AGB; infrared: stars

Sažetak
Evolution of symbiotic Miras and interaction between the stellar environment and components of the binary system can be properly understood only by knowing the geometry and properties of the circumstellar dust. In order to find the properties and geometry of the dust surrounding the Mira component of the symbiotic binary RR Tel we used the DUSTY numerical code to model the near- and mid-IR spectra and colour indices of this star. The most prominent dust properties determined by this procedure were sublimation temperature, grain size, dust distribution, optical depth and mass loss rate. The spectral energy distribution was reconstructed from available observations during and outside obscuration epochs. Long-term changes in dust properties were determined by modelling temporal variations of colour indices. Pulsation properties and long-term periodic variability were found from the near-IR light curves. Our model of the circumstellar environment and its dynamical behaviour in RR Tel outside obscuration epochs gave evidence of an optically thin circumstellar dust envelope and an optically thick dust region outside the line of sight. Without significant obscuration by dust, the emission from the Mira can be observed almost unattenuated. Obscuration events in RR Tel are explained by an increase in optical depth caused by the newly condensed dust in the sublimation region and a higher mass loss. This leads to the formation of a compact silicate dust shell of about 1200 K sublimation temperature. The shell is shielded from the influence of the hot component.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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