# Strömgren sphere

> sphere of ionized hydrogen around a young star of the spectral classes O or B

**Wikidata**: [Q1504097](https://www.wikidata.org/wiki/Q1504097)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Strömgren_sphere)  
**Source**: https://4ort.xyz/entity/str-mgren-sphere


## References

1. Freebase Data Dumps. 2013