Herbig-Haro Object
Herbig-Haro object
[¦hər·big ′hä·rō ‚äb·jəkt]Herbig-Haro Object
a celestial object that is a small, irregularly shaped condensation of gas and dust and is associated with dark clouds of diffuse material in the Galaxy. Herbig-Haro objects are located in regions that are rich in T Tauri variable stars; they are known to be young formations. The objects were discovered by G. Herbig of the USA and G. Haro of Mexico between 1948 and 1952.
The angular sizes of Herbig-Haro objects usually lie in the range of 1”–10”, which corresponds to several thousand astronomical units. The spectra are subdivided into two types: (a) a weak continuous spectrum together with strong hydrogen emission lines and forbidden lines of oxygen, nitrogen, and sulfur; (b) a continuous spectrum of light from an illuminating star that is scattered by dust.
Herbig-Haro objects are believed to be the gas and dust envelopes of stars that are forming by the condensation of diffuse matter. The intensity of the radiation from the objects fluctuates. The differences in the types of spectra are probably attributable to different stages in the evolution of the objects.
REFERENCE
Eruptivnye zvezdy. Moscow, 1970. Pages 287–89.B. V. KUKARKIN