# XX Hydrae

> RR Lyrae variable star in the constellation Hydra

**Wikidata**: [Q93895604](https://www.wikidata.org/wiki/Q93895604)  
**Source**: https://4ort.xyz/entity/xx-hydrae


## References

1. SIMBAD
2. Gaia Data Release 3
3. Probing the outer galactic halo with RR Lyrae from the Catalina surveys
4. Discovery of ~9,000 new RR Lyrae in the southern Catalina surveys
5. Gaia Data Release 2
6. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
7. Gaia Early Data Release 3