I recently aquired the Dawnbreaker Sword from Meridias' Breaking Dawn quest with two of my characters and I was wondering if someone can shed light on why it glows at certain points while I'm traveling does it detect undead, treasure or cave locations.Does it react to enemies sort of like Lotr Sting sword?

It glows red when undead are around, I'm not sure about the other colours. I dislike the glowy ball thing on the hilt.

lol Meridia tells you what it does when she gives it to you. And the weapon has a description. Its basically supposed to be a light in dark places. It will glow white or red when anything evil is around.

it glows when undead are around. (vampires, Draugr, skeletons, etc.)

sometimes it just randomly lights up even without those enemies around. i use it all the time

Lights when enemies are near I didn't think it mattered about what type.