A Herbig-Haro (HH) object is:_:. a. a small galaxy just outside the outer edge of the Milky Way
b. where a jet from a star in the process of being born collides with (and lights up) a nearby cloud of interstellar matter
c. a part of a giant molecular cloud where molecules containing two hydrogen atoms form
d. a star that has too little mass to start fusion in its core
e. cluster of very low-mass stars, observable only with infrared radiation