Enhanced optical activity 12 days before X-ray activity, and a 4 day X-ray delay during outburst rise, in a low-mass X-ray binary

X-ray transients, such as accreting neutron stars, periodically undergo outbursts, thought to be caused by a thermal-viscous instability in the accretion disk. Usually outbursts of accreting neutron stars are identified when the accretion disk has undergone an instability, and the persistent X-ray flux has risen to a threshold detectable by... Show more