# Helix Nebula

> planetary nebula

**Wikidata**: [Q97017154](https://www.wikidata.org/wiki/Q97017154)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Helix_Nebula)  
**Source**: https://4ort.xyz/entity/helix-nebula


## References

1. SIMBAD
2. VizieR
3. A spectroscopic survey and analysis of bright, hydrogen-rich white dwarfs
4. Freebase Data Dumps. 2013
5. Optical Multicolor Photometry of Spectrophotometric Standard Stars
6. Gaia Data Release 2
7. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
8. Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Radial velocities: The Wilson-Evans-Batten catalogue