India’s first multi-wavelength space-based observatory AstroSat has detected bright sub-second X-ray bursts from a new and unique neutron star with ultrahigh magnetic field (magnetar).
- X-ray bursts occurs in low-mass X-ray binary systems where a neutron star and low-mass main sequence star are in orbit around one another.
- Due to their close proximity and the extreme gravity of the neutron star, the companion star overflows its roche-lobe and hydrogen is drawn into an accretion disk around the neutron star.
- This hydrogen is eventually deposited on the surface of the neutron star and immediately is converted into helium due to the extreme temperatures and pressures that exist there.
- A thin surface layer of helium is built up, and once a critical mass of helium is reached, it ignites explosively, heating the entire surface of the neutron star to several tens of millions of degrees releasing a sudden burst of X-rays.
- Once the outburst is over, the binary system temporarily returns to its quiescent state while the neutron star begins to re-accumulate the helium surface layer.
- The process repeats resulting in recurrent X-ray bursts.
- It generally occurs at regular intervals separated by several hours or days.