Is System.Threading.Timer enabled or running?

I'm starting a timer with the following code

    _timer = new System.Threading.Timer ((o) => {
                                Console.WriteLine("hello from the timer");
                            }, null, 0, 10000);

After other events, I use _timer.Dispose();

I noticed the timer object has a 'disposed' property, but how can I access it? I need to check if I have disposed of the timer or not at other points on the activity.