The way to a double degenerate: ∼15-20 per cent of 1M⊙ ≤ M ≤ 8M⊙ stars have an M > 1M⊙ companion

We find that similar to 15-20 per cent of A-type stars or red giants are bound with a massive companion (M-secondary > 1M(circle dot)) in an intermediate wide orbit (0.5 < P < 5000 yr). These massive binaries are expected to form wide-orbit, double-degenerate systems (WODDs) within less than or similar to 10 Gyr implying that similar to 10 per cent of white dwarfs (WDs) are expected to be part of a WODD with a lighter WD companion. These findings are based on an analysis of previous adaptive optics observations of A-type stars and radial velocity measurements of red giants and shed light on the connection between multiplicity function of stars and detected double degenerates. We expect that Gaia will find similar to 10 new WODDs within 20 pc from the sun. These results put a stringent constraint on the collision model of Type Ia supernovae in which triple stellar systems that include a WODD as the inner binary are required to be abundant.