If the star lost more than 1/2 of its mass, the planet's speed would exceed the escape velocity from what ever remains of the star, and be ejected from the solar system. The enormous flux of particles ejected from the star assuming 10 solar masses, a shell thickness of 1 million kilometers and a radius equal to the Earth's orbit would be about 10^19 atoms per cubic centimeter traveling at 10,000 kilometers per second. When it strikes an Earth-like atmosphere and the particle energy is thermalized, it would appear like injecting a gas with a temperature of 5 billion degrees per hydrogen atom. ( 1/2 m v^2 = kT with m = mass of a hydrogen atom). The earth would probably not be vaporized ,but its atmosphere would be boiled off into space to join the expanding supernova remnant. If the planet were far away, like the orbit of Neptune at 2 billion miles, the flux of particles would be reduced by ( 2 billion/93 million)^2 = 460 times, and the adiabatic expansion of the gas would probably reduce its energy so that distant planets might be able to hold on to some of their atmospheres. Most of the ejected mater would clear out of the solar system within a few weeks or months, but there is lots of other matter being accelerated by the trapped magnetic fields to make for a constant flux of lethal radiation within the newly-formed 'cavity' plowed-out by the passing shock wave. The planetary surfaces would be bombarded by a hellish cosmic ray flux for thousands of years, and it is hard to believe life could survive.
These are my educated guesses.