# Mixed chemistry phenomenon during late stages of stellar evolution

## TL;DR

This paper investigates the mixed chemical environments around evolved stars, confirming binary models for silicate carbon stars and exploring C-stars with OH emission, enhancing understanding of late stellar evolution.

## Contribution

It provides observational evidence supporting the binary model scenario for silicate carbon stars and discusses a class of C-stars with OH emission.

## Key findings

- Confirmed binary model scenario for silicate carbon stars
- Identified C-stars with OH emission linked to [WR] planetary nebulae
- Enhanced understanding of chemical phenomena in late stellar evolution

## Abstract

We discuss phenomenon of simultaneous presence of O- and C-based material in surroundings of evolutionary advanced stars. We concentrate on silicate carbon stars and present observations that directly confirm the binary model scenario for them. We discuss also class of C-stars with OH emission detected, to which some [WR] planetary nebulae do belong.