What are these and who do I call?

These wires from the pole to my house have been starting to sag quite a bit and now this cable seems to have decoupled from itself over my driveway. Is this a power line? It's kinda hard to tell which wire is which after it gets onto the roof so I'm not sure, but no services seem to be affected by this one being decoupled.

I'm a relatively new homeowner so I don't know if this is something I call Eversource to fix or hire an electrician? Assuming it's even a power line thing... Can anybody identify it and point me in the right direction?