輝線 is read as きせん (kisen) and means bright line.
きせん
kisen
かがやかしい
brilliant
きど
brightness
かがやく
to light up (with happiness, hope, etc.)
かがやき
かがやかす
to light up
かがやくじょせい
women who excel
きせきあんざんがん
pyroxene andesite
きどしんごう
luminance signal
きてん
always-on pixel (as a defect in LCD displays)
きせき
pyroxene
かがやきわたる
to shine out far and wide
しんかんせん
Shinkansen