This is what Callerlab says. Even in Tech Squares it's considered incorrect to call it from other formations.
24. Star Thru
Starting formation: Facing Dancers (man facing woman)
Command example: Star Thru
Dance action: Man places his right hand against woman's left hand, palm to palm with fingers up, to make an
arch. As the dancers move forward the woman does a one quarter (90 degrees) left face turn under the arch,
while the man does a one quarter (90 degrees) turn to the right moving past the woman.
Ending formation: Couple
Timing: 4
Styling: Hands are joined in raised position at approximately eye level, palm to palm, with fingers pointed up to
form an arch. The arch will be offset to the man's right and woman's left. The man's hand should be used to
stabilize as the woman provides her own momentum. As the call is completed, the hand grip should be
readjusted to couple handhold.