Guillermo Haro Barraza (Spanish pronunciation: [ɡiˈʝeɾmo ˈaɾo βaˈrasa];[1] 21 March 1913 – 26 April 1988) was a Mexican astronomer.

[2] As a result of his dedication and enthusiasm for astronomy, he was hired by Erro in 1943 as an assistant at the newly founded Observatorio Astrofísico de Tonantzintla.

[citation needed] Among them were the detection of a large number of planetary nebulae in the direction of the Galactic Center and the discovery (also independently done by George Herbig) of the nonstellar condensations in high density clouds near regions of recent star formation (now called Herbig–Haro objects).

[citation needed] Other major research projects carried out by Haro included the list of 8746 blue stars in the direction of the north galactic pole published jointly with W. J. Luyten in 1961.

[citation needed] Guillermo Haro discovered a new type of large nebulae with American colleague George Herbig - that were named Herbig-Haro objects.

[2] Haro founded the Mexican Academy of Sciences (first president 1960) and the National Institute of Astrophysics, Optics and Electronics (an observatory named after him is in the state of Sonora).