Herbig–Haro object
![Herbig–Haro object HH47, imaged by the Hubble Space Telescope. The scale bar represents 1000 Astronomical Units](/Images/godic/202501/18/HST_HH47_image3435.jpg")
![](/Images/godic/202501/18/LH_953435.jpg")
![HH objects HH1 and HH2 lie about a light year apart, symmetrically opposite a young star which is ejecting material along its polar axis](/Images/godic/202501/18/HH1_and_HH2_imaged_by_WFPC23435.jpg")
![Schematic diagram of how HH objects arise](/Images/godic/202501/18/HH_object_diagram.svg3435.png")
Herbig–Haro (HH) objects are small patches of nebulosity associated with newly born stars, and are formed when narrow jets of gas ejected by those stars collide with nearby clouds of gas and dust at speeds of several hundred kilometres per second. Herbig–Haro objects are ubiquitous in star-forming regions, and several are often seen around a single star, aligned with its rotational axis.