Contributed Talk - Splinter ISM

Wednesday, 23 September 2020, 17:40   (virtual room F)

IRAS 07077+1536: A dusty C-star with a peculiar SED

Thomas Garmatter, A. Beate C. Patzer
Zentrum für Astronomie und Astrophysik, TU Berlin

Carbon stars on the asymptotic giant branch (AGB) contribute very significantly not only to the chemical enrichment of the interstellar medium (ISM) but also to the infrared light of galaxies. C stars (C/O> 1) are usually characterized by spectral bands of carbon containing molecules (e.g. CN, C2) and by large infrared (IR) excesses caused by dusty circumstellar envelopes (CSEs) absorbing the stellar light, re-emitted at longer wavelength. Observations of IRAS 07077+1536 revealed a dusty C-star but with a peculiar spectral energy distribution (SED) in the blue colors. Based on new observational results especially by Gaia DR2 and LAMOST we make radiative transfer calculations to perform the SED fitting of IRAS 07077+1536 in order to determine its important stellar properties. In this conference contribution we present our findings on effective temperature, luminosity, mass loss rate, dust composition and terminal velocity of the circumstellar outflow for example. Thereby, we also disclose the true cause of the unusual enhanced 'blue emission'.