Are they hot gas or streams of charged particles?
Complex jets of material are being ejected from CRL 618 in the form of rings, knots, and twisted streamers of glowing gases. The overall shape of the so-called “planetary nebula” reveals two gigantic, bifurcated jets emerging from the star, indicating the beginnings of a helical shape. According to prevailing theories, red giant stars expand outward because they have “burned” most of their primordial hydrogen and have entered another stage of life where they are consuming the helium that was created in thermonuclear fusion reactions. As hydrogen atoms fuse into helium, the helium (being heavier than hydrogen) sinks into the stellar core, where it accumulates over millions, if not billions, of years. Once the star has exhausted its hydrogen fuel supply, it contracts because radiative pressure is no longer sufficient to overcome the gravitational force that is always trying to pull the star’s outer surface down into its core. As the contraction continues, the internal pressure rises and
