Temporal fluctuation
Temporal fluctuations are a detectable energy phenomena which can occur when an object or person travels to another time continuum.

Such a fluctuation was detected by Lieutenant Commander Data in 2369, when aliens from another time continuum and a Romulan Warbird vanished due to severe distortions caused by a temporal aperture. ()

See also
Chronometric distortion
Temporal flux
Temporal signature
Energy
Time travel