How do i make the camera rotate around the Y axis?

I’m trying to make the camera rotate around the player on the y axis (Horizontaly) to get a view from above as well as below and tried using this:

v = new Vector3 (y, 0, 0);
transform.RotateAround (target.forward, v, 1f);

For some reason, this rotates the X axis as well and i’m clueless to how i can stop it.
Please help.

To rotate around the y axis use the following

  transform.RotateAround(target.position, Vector3.up,  speed*Time.deltaTime);

However I’m not sure you are trying to rotate around the y axis in unity. Vector3(x, y, z) so Vector3(c, 0, 0) is a vector along the x axis. Also the y axis is up - down so rotating around the y axis will rotate the view between left, front, right, back and will not rotate between above and below.