An Etymological Dictionary of Astronomy and Astrophysics

An → X-ray binary system that has a long period of → quiescence interrupted by → outbursts of low-energy → soft X-rays. Alternatively known as X-ray novae, the majority (~ 75%) of SXTs contain a → black hole and a low-mass → main sequence  → companion star in orbit around one another.
It is thought that SXTs arise in a similar manner to → dwarf novae, through instabilities in the → accretion disk around the → compact object (→ disk instability model).

See also: → soft; → X-ray;
→ transient..