# Pi4 Orionis

> spectroscopic binary star system in the constellation Orion

**Wikidata**: [Q14222](https://www.wikidata.org/wiki/Q14222)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Pi4_Orionis)  
**Source**: https://4ort.xyz/entity/pi4-orionis


## References

1. SB9: The ninth catalogue of spectroscopic binary orbits
2. SIMBAD
3. New Catalogue of Suspected Variable Stars
4. Rotational velocities and spectral types for a sample of binary systems
5. The kinematics of the Gould belt: an expanding group ?
6. Freebase Data Dumps. 2013
7. UBV photometry of stars whose positions are accurately known. VII
8. Catalogue of Stellar Photometry in Johnson's 11-color system
9. Gaia Data Release 2
10. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system
11. Carbon, nitrogen, and oxygen abundances in early B-type stars
12. The IACOB project. I. Rotational velocities in northern Galactic O- and early B-type stars revisited. The impact of other sources of line-broadening
13. The IACOB project. III. New observational clues to understand macroturbulent broadening in massive O- and B-type stars
14. Validation of the new Hipparcos reduction