Mass-transfering Binary Star

What is the known distance between a mass transfering binary system? Would 886,700,000 miles be considered too close for a binary system? (On video) Whats the diameter in km of these binary stars? What is the distance between them?

The video depicts two interacting "white dwarf" stars. Each has a diameter that is only 1% the diameter of our Sun, i.e., about 8800 km. The two stars are initially separated by only about 15,000 km. In our local region of the Milky Way Galaxy, a dozen double-white-dwarf binaries like this have been discovered. One of the nearest such systems is AM CVn (constellation Canes Venatici); it is about 750 light-years away from the Solar system, i.e., about 11 million billion miles away.

Hu jet53man, good video. So two binary dwarf stars (both mainly consist of Carbon and Oxygen and less than 1.4 solar mass) basically collide into one contact star? And what would happen if one of the sister stars was a red gas giant? My friend said the white dwarf would supernova (type Ia) if it's solar mass was more than 1.4? Is that true?

I do not think that the mass above would cause a super nova because those are created bye the core of a star using nuclear fuision with iron with out energy the sun implodes but two Binary stars collidng usaly makes 1 new star judging bye the stars in this video a red straggler the red staggler has lesss or double mass lumoisity and heat so if it were 2 neautron stars Yes they would explode

How many modes must a star spin down
Before you call it spun down?
The answer, my friend, is blowin' in the stream