# 2 Hydrae

> star in the constellation Hydra

**Wikidata**: [Q1028424](https://www.wikidata.org/wiki/Q1028424)  
**Source**: https://4ort.xyz/entity/2-hydrae


## References

1. SIMBAD
2. Michigan catalogue of two-dimensional spectral types for the HD Stars, Vol. 5
3. Washington Double Star Catalog
4. Gaia Data Release 3
5. The Tycho-2 catalogue of the 2.5 million brightest stars
6. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
7. Gaia Early Data Release 3
8. Testing different methods for atmospheric parameters determination. The case study of the Am star HD 71297
9. New measurements of rotation and differential rotation in A-F stars: are there two populations of differentially rotating stars?
10. Validation of the new Hipparcos reduction