Version: 2017.1
public void RotateAround (Vector3 point, Vector3 axis, float angle);


Rotates the transform about axis passing through point in world coordinates by angle degrees.

This modifies both the position and the rotation of the transform.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { void Update() { transform.RotateAround(, Vector3.up, 20 * Time.deltaTime); } }