TT Cygni
TT Cygni is a carbon star. It is 561 parsecs (1,830 ly) away in Cygnus. It has an apparent magnitude of 7.44.[1] It is called a carbon star because it has a high ratio of carbon to oxygen in its surface layers. The carbon was produced by helium fusion, dredged up from inside the star. A shell of carbon monoxide, about half a light year across, was emitted 6,000 years before the star was as it appears from Earth now.
References
- ↑ 1.0 1.1 1.2 "TT Cygni". SIMBAD Astronomical Database. Centre de Données astronomiques de Strasbourg. Retrieved 20 January 2014.