The 'Rapid Burster' was discovered by Walter Lewin and colleagues in 1976. It is located in the globular cluster Liller 1 at a distance of 10 kiloparsecs. MXB1730-335 emits a series of X-ray bursts lasting 2 to 680 seconds and reoccurring after 10 seconds and 1 hour respectively with X-ray luminosities of 4 x 10^38 ergs/sec about 100,000 the luminosity of the Sun. The bursts are believed to originate in an instability in the accretion disk orbiting a neutron star in the MXB1730-335 binary system, but no one knows exactly what this instability is. There are also 'Type I' flashes caused by matter falling onto the surface of the neutron star and producing thermonuclear fusion. For more information, have a look at the brief review of this object in a 1996 Astrophysical Journal article.