STAR Connection
The ends of the phases are connected together to form the so-called neutral- or star point. If all three resistors are the same size, the phase currents cancel each other out at the zero point and the neutral line can be omitted.

3 Phase Current - Star-connection - Voltage and Current values
What you can see from the circuit:
In Star connection the line current is equal to the phase current: ILine = IPhase
What about the voltage? The relation between the Line voltage and the Phase voltage can be derived from the pointer diagram:

Star connection - Relation between Line voltage and Phase Voltage
In star Connection the Line Voltage is √3 times of Phase Voltage: VLine = √3 VPhase