An X-ray binary about 17 000 l.y. away in the constellation Aquila, consisting of a normal star with a compact companion, either a neutron star or black hole. It lies in an old supernova remnant designated W50, which is presumably the debris of the event that produced the compact object. The binary has an orbital period of 13 days and appears optically as a variable star, V1343 Aquilae, of 14th magnitude. The light from an accretion disk around the compact object makes it difficult to identify the spectral type of the normal star, but it is probably of a few solar masses. SS433 is notable for the twin jets of gas being expelled from the face of the system's accretion disk at 78 000 km/s (about one-quarter the speed of light). Precession of the accretion disk causes the jets to sweep out a 40° cone which is perpendicular to the face of the disk. The jets are visible at radio, optical, and X-ray wavelengths.
Subjects: Astronomy and Astrophysics.