Usually, two of the stars form a close binary system, and the third orbits this pair at a distance much larger than that of the binary orbit.
PSR J1903+0327 is a millisecond pulsar in a highly eccentric binary orbit.
The second, smaller star of the binary orbits very closely and may even have been engulfed by the other's expanding stellar atmosphere with the resulting interaction creating the nebula.
They realized that such behavior is predicted if the pulsar were in a binary orbit with another star.
This system consists of a pair of stars in a binary orbit with a period of 813 days and an eccentricity of 0.183.
Einstein's general theory of relativity predicts that massive objects in short binary orbits should emit gravitational waves, and thus that their orbit should decay with time.
Through the emission of gravitational radiation, the binary loses angular momentum, which causes the binary orbit to shrink.
Soon after the onset of mass transfer, the orbital evolution will reverse and the binary orbit will expand.
Common envelope event begins when by whatever reason a binary orbit begins to decay or one of star expands rapidly.
He was something of a child prodigy, having two papers on binary orbits (celestial mechanics) published before he was sixteen.