I tried doing the same as in the video in an earlier alpha 7 preview and here's the properties of the stellar remnant. It's made of pretty much only silicate. Its mass is 0.56 solar masses (the mass of the star when it exploded was about 2 suns), so Xriqxa is correct that it's probably a white dwarf. I thought that the star was much more massive in the video when it exploded, because I thought it was a supernova, and therefore that the remnant was probably a neutron star.