1.   If stars emitted radiation equally in all wavelengths, this effect would indeed be cancelled out by other radiation redshifted into the visible range.

2.   In fact, these stars emit so little optical light that they seem, to the human eye, to disappear.

3.   Researchers realized the star was emitting a thin, plane-shaped beam of intense infrared light.

4.   Stars emit light from their hot glowing gases.

5.   The astronauts plan to remove a pair of telephone booth-sized instruments that analyze the ultraviolet radiance that stars emit.