Two planets orbiting each other.
The barycenter of the planets must not lie within either planet but must be in free space between them. (The planets orbit a central point as opposed to a planet-sattelite configuration where one body orbits another)
None. Pluto-Charon was almost considered one in 2006, though that would be a dwarf double planet rather than a true double planet as Pluto is not a planet. In billions of years the Earth and Moon will be a double planet. Also, the question is non-sensical because if it was a double planet then they would both be planets... so there would be no moon. A planet would be considered a double planet with it's opposite planet, not moon.
First of all, Pluto is not a planet. It was considered a double planet because its largest moon Charon is half its size.
Live on the Double Planet was created in 1986-07.
Some consider it to be a double planet or, more properly, a double dwarf planet. However it is currently not officially considered as such.
Little Mick
Mercury has a double sunrise.
That's easy its pluto
Jupiter
Within our own solar system, some view Pluto as being a double planet with it's moon Charon (which is half it's size).
When Pluto was still officially considered a "planet" in our solar system, it and it's moon Charon were considered by many to be a double planet system. Whenever a moon constitutes a considerable percentage of the host planet's mass, it may be considered a double planet system. For this reason, some consider the Earth and our moon to be a double planet system. Our system has by far the greatest planet to moon mass ratio; about 6:1. As for planets outside our solar system, I cannot say. Though there are many out there.
There are no double planet systems in our solar system. The closest to being considered a double planet are Pluto and its largest moon Charon, but since Charon is significantly smaller than Pluto, it is not classified as a double planet system.
Earth and the Moon.