Stars

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Across
  1. 2. A large cloud of gas and dust in space
  2. 4. The blue-white hot core of a star that is left behind after its outer layers have expanded and drifted out into space
  3. 6. A contracting cloud of gas and dust with enough mass to form a star
Down
  1. 1. The brightness of a star as seen from Earth
  2. 3. The brightness a star would have if it were at a standard distance from Earth
  3. 5. The explosion of a dying supergiant star