2013/01/18 by T. Kamiński, T. Kaminski, C. A. Gottlieb +13 · 2 citations
Physics and Astronomy · #Astro and Planetary Science #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/201220290
published as Astron. Astrophys. 551 (2013) A113 · to appear in Astronomy and Astrophysics
arxiv created 2013/01/18 · openalex publication_date 2013/02/01 · arxiv updated 2013/12/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
We report the first detection of pure rotational transitions of TiO and TiO2 at (sub-)millimeter wavelengths towards the red supergiant VY CMa. A rotational temperature, Trot, of about 250 K was derived for TiO2. Although Trot was not well constrained for TiO, it is likely somewhat higher than that of TiO2. The detection of the Ti oxides confirms that they are formed in the circumstellar envelopes of cool oxygen-rich stars and may be the “seeds” of inorganic-dust formation, but alternative explanations for our observation of TiO and TiO2 in the cooler regions of the envelope cannot be ruled out at this time. The observations suggest that a significant fraction of the oxides is not converted to dust, but instead remains in the gas phase throughout the outflow.