- Though some ideas of quark stars were proposed as early as in 1969 , no great progress had been made until the 1980s
- Such sources are believed to be either quark stars or neutron stars , and a subclass of these are already observed by conventional means as pulsars or x - ray emitting celestial objects
- Gravitational waves are ripples in the fabric of space and time produced by events in our galaxy and throughout universe , such as black hole collisions , shockwaves from the cores of exploding supernovas , and rotating pulsars , neutron stars , and quark stars
A quark star or strange star is a hypothetical type of exotic star composed of quark matter, or strange matter. These are ultra-dense phases of degenerate matter theorized to form inside particularly massive neutron stars.