Titanium Carbide Nanocrystals in Circumstellar Environments

TLDR: It is concluded that titanium carbide forms during a short (approximately 100 years) phase of catastrophic mass loss in dying, low-mass stars.

Abstract: Meteorites contain micrometer-sized graphite grains with embedded titanium carbide grains Although isotopic analysis identifies asymptotic giant branch stars as the birth sites of these grains, there is no direct observational identification of these grains in astronomical sources We report that infrared wavelength spectra of gas-phase titanium carbide nanocrystals derived in the laboratory show a prominent feature at a wavelength of 201 micrometers, which compares well to a similar feature in observed spectra of postasymptotic giant branch stars It is concluded that titanium carbide forms during a short (approximately 100 years) phase of catastrophic mass loss (>0001 solar masses per year) in dying, low-mass stars