The ESA Gaia astrometric mission has enabled the remarkable discovery that a large fraction of stars near Solar neighbourhood appear to be debris from single in-falling system, so-called Gaia-Enceladus-Sausage (GSE). One exciting feature this result is it gives astronomers for first time sample easily observable unevolved formed in an extra-Galactic environment, which can compared within our Mi...

We study the pycnonuclear burning of 34Ne in the inner crust of an accreting neutron star. We show that the associated energy production rate can be calculated analytically for any arbitrary temporal variability of the mass accretion rate. We argue that the theoretical time-scale for 34Ne burning is currently very uncertain and ranges from a fraction of a millisecond to a few years. The fastest...

We study the ‘minimal’ cooling scenario of superfluid neutron stars with nucleon cores, where the direct Urca process is forbidden and enhanced cooling is produced by neutrino emission due to the Cooper pairing of neutrons. Extending our recent previous work, we include the effects of surface accreted envelopes of light elements. We employ the phenomenological density-dependent critical tempera...

Nuclear reactions in accreting neutron-star crusts and the heat release accompanying them are studied, under different assumptions concerning the composition of the outermost layer formed of the ashes of X-ray bursts. Particular examples of ashes containing nuclides with A ≃ 90−110 are considered and compared with a standard A = 56 case. In all cases, evolution of a crust shell is followed from...

We show that HI clouds in the Magellanic Clouds are stripped by the ram-pressure due to the halo and disk gases of the Galaxy. Molecular clouds are swept to the edge of the LMC, showing an eccentric distribution. The stripped HI clouds form a narrow band on the sky, and mimics the Magellanic Stream, when the LMC takes a polar orbit. We point out that the Magellanic Stream will fall into the Gal...

We study the long term evolution of a solar type star that is being disrupted by a super massive (10 M⊙) black hole. The evolution is followed from the disruption event, which turns the star into a long thin stream of gas, to the point where some of this gas returns to pericenter and begins its second orbit around the black hole. Following the evolution for this long allows us to determine the ...