Magnetascopic interference

From Memory Alpha, the free Star Trek reference.

Magnetascopic interference is a type of interference caused by some protostars, which impairs the function of most starship sensors. The directional array of a Galaxy-class starship is a capable of cutting through the interference, but it has a very narrow scan field.

While undercover within the Maquis in 2370, Ro Laren took advantage of magnetascopic interference in the Topin system to steal medical supplies from the USS Enterprise-D. (TNG: "Preemptive Strike")