There is no usage guidance for this tag … yet!
Usage guidance, also known as a tag wiki excerpt, is a short blurb that describes when and why a tag should be used on this site specifically.
A flare star is a variable star that can undergo unpredictable dramatic increases in brightness for a few minutes.
A satellite flare is a a phenomenon caused by the reflective surfaces on satellites.
For plasma eruptions from the surface of the sun, use solar-flare.