Across
- 2. a cloud of gas and dust in outer space, visible in the night sky either as an indistinct bright patch or as a dark silhouette against other luminous matter.
- 6. a theoretical stellar remnant, a white dwarf that has cooled down to the point where it no longer emits any light or heat
- 8. a star that spends the majority of its life fusing hydrogen into helium in its core.
- 9. a graph that plots the absolute magnitudes (or luminosities) of stars against their surface temperatures
- 10. flat, thin, and circular like a disk.
- 11. a system of millions or billions of stars, together with gas and dust, held together by gravitational attraction.
- 12. the energy source of the Universe, occuring in the core of the Sun and stars
Down
- 1. all existing matter and space considered as a whole; the cosmos
- 2. is an interaction between two nuclear particles or two nuclei that results in the formation of new nuclei different from the original ones
- 3. a small very dense star that is typically the size of a planet.
- 4. a star that has expanded significantly in size and luminosity compared to a main-sequence star of the same surface temperature
- 5. Spectral classes are a way of classifying stars based on their surface temperature, and they are denoted by letters
- 7. the intrinsic brightness of a celestial object (as distinct from its apparent brightness diminished by distance).
- 8. the name of the galaxy that our solar system is a part of. It's a barred spiral galaxy containing billions of stars, including our Sun, and numerous planets.