That is the right answer. I would do it this way, using the fact that , where is the complex conjugate of z. Then is equivalent to . Multiply that out and rearrange it as . Now "complete the square" (except that it's not a square, but the method is the same) to write this as . Finally, take the square root to get , which is the equation of a circle centred at 1/3, with radius 1/3.