IRAS 19227+1700: A carbon-rich or oxygen-rich start?

In the new version of the catalogue of carbon stars, IRAS 19227+1700 is listed as a carbon-rich sta. However, in the IRAS infrared two-color diagram, it is located in the typical region of stars with rather thick oxygen-rich circumstellar envelopes, and not in the region commonly occupied by silicate carbon stars. Moreover, there are other pieces of evidence that show that this star not only has the main and satellite line OH maser emissions, but also has water emission close to the central star. Its IRAS low- resolution spectrum (LRS) displays dust emission features in the range of 9–12 μm, and near infrared observation has confirmed that it really possesses a hot circumstellar envelope. Therefore, the circumstellar envelope of IRAS 19227+1700 should be completely oxygen-rich in nature, and quite possibly its central star is also oxygen-rich.