Read the following paragraph and answer the question. Give ONLY the answer, no other words or explanation.

For example:

Answer: <most likely answer, as short as possible>.

Paragraph: 
The sun and other stars produce light because they are so hot. They glow with light due to their extremely high temperatures. This way of producing light is called incandescence . Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence . Objects that produce light by luminescence are said to be luminous. Luminescence, in turn, can occur in different ways:.


Question: Producing light without heat is called what?
luminescence
Luminescence.