An incredible condition is that of a binary system where one, or both the stars are neutron stars. The gravity field of a neutron star is solarge that it can suck up matter from nearby stars. Thsi is how Wikipedia describes such an astounding system
Disrupted recycled pulsar[edit]
When two massive stars are born close together from the same cloud of gas, they can form a binary system and orbit each other from birth. If those two stars are at least a few times as massive as our sun, their lives will both end in supernova explosions. The more massive star explodes first, leaving behind a neutron star. If the explosion does not kick the second star away, the binary system survives. The neutron star can now be visible as a radio pulsar, and it slowly loses energy and spins down. Later, the second star can swell up, allowing the neutron star to suck up its matter. The matter falling onto the neutron star spins it up and reduces its magnetic field. This is called “recycling” because it returns the neutron star to a quickly-spinning state. Finally, the second star also explodes in a supernova, producing another neutron star. If this second explosion also fails to disrupt the binary, a double neutron star binary is formed. Otherwise, the spun-up neutron star is left with no companion and becomes a “disrupted recycled pulsar”, spinning between a few and 50 times per second.[28]
Pulsars make up extremely accurate clock and are used also to this puprose:
Precise clocks[edit]
Generally, the regularity of pulsar emission does not rival the stability of atomic clocks.[32] For some millisecond pulsars, the regularity of pulsation is more precise than an atomic clock.[33] This stability allows millisecond pulsars to be used in establishing ephemeris time[34] or building pulsar clocks.[35]
Timing noise is the name for rotational irregularities observed in all pulsars. This timing noise is observable as random wandering in the pulse frequency or phase.[36] It is unknown whether timing noise is related to pulsar glitches.
