Across
- 4. The joining together of hydrogen nuclei to form Helium (6)
- 7. a sun-sized star after main sequence, outer layers swelling and cooling (3,5)
- 9. a medium star exploded leaving a small hot dense remaining center (5,5)
- 12. the limit of pressure of a white dwarf to collapse (8,10)
- 14. The emissions given off by any object with thermal energy in it (9,10)
- 15. An extremely massive star
- 16. Interstellar cloud of dust and gas (6)
- 17. The force responsible for the gathering of a protostar (7)
- 18. The source of a star's radiation energy (6)
Down
- 1. The coloured nebulous remains around a white dwarf (9,6)
- 2. Colour of the hottest stars in the universe (4)
- 3. A large star collapsed into a singularity (5,4)
- 5. A large star collapsed to about 20km diameter (7,4)
- 6. The stable Hydrogen-burning phase of a star's life (4,8)
- 8. A small star(5)
- 10. The fuel source of a Red Giant, after Hydrogen fusion ends (6)
- 11. The metal element at the center of large mature stars (4)
- 13. The least energetic of the ionizing Electromagnetic waves (11)
- 15. Extremely bright explosion of a star (9)