Kirchhoff was the first to describe qualitatively the types of ...

[sabina]

Kirchhoff was the first to describe qualitatively the types of spectra we observe from luminous objects. Describe the three types and their sources.
 
  What will be an ideal response?

Question 2

Objects which have contracted, but are of too little mass to establish thermonuclear reactions in their cores, are ________, which slowly continue to cool.
 
  Fill in the blank(s) with correct word

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Answer to Question 1

His first law has dense hot objects creating a continuous spectrum. In the second law, a low density hot gas gives off bright emission lines. In the third law, a cool thin gas in front of a continuous source will absorb some of the energies, creating dark lines in the spectrum.

Answer to Question 2

brown dwarfs

[sabina]

TYSM

[aliotak]

Excellent