Figure 18-1: R I V U X G
The Orion Nebul (a) The middle “star” of the three that make up Orion’s sword is actually an interstellar cloud called the Orion Nebula. (b) The nebula is about 450 pc (1500 ly) from Earth and contains about 300 solar masses of material. Most of the ultraviolet light that makes the nebula glow comes from just five hot massive stars.
The Orion Nebul (a) The middle “star” of the three that make up Orion’s sword is actually an interstellar cloud called the Orion Nebula. (b) The nebula is about 450 pc (1500 ly) from Earth and contains about 300 solar masses of material. Most of the ultraviolet light that makes the nebula glow comes from just five hot massive stars.
(a: Australian Astronomical Observatory/David Malin Images; b: NASA,ESA, M. Robberto [Space Telescope Science Institute/ESA] and the Hubble Space Telescope Orion Treasury Project Team)