Herbig-Haro object. Artist's animation showing formation of a Herbig-Haro object, a cloud of gas and dust formed when jets of gas are ejected from young stars. Stars form from the gravitational collapse of a cloud of gas and dust. As infalling material spirals onto the new star, jets erupt from its poles to balance angular momentum. The jets collide at high speed with material surrounding the star, heating them and causing them to glow. These objects are relatively short lived, lasting only a few thousand years.