We report the first detection of pure rotational transitions of TiO and TiO _ { 2 } at ( sub- ) millimeter wavelengths towards the red supergiant VY CMa .
A rotational temperature , T _ { rot } , of about 250 K was derived for TiO _ { 2 } .
Although T _ { rot } was not well constrained for TiO , it is likely somewhat higher than that of TiO _ { 2 } .
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 TiO _ { 2 } in the cooler regions of the envelope can not 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 .