Q&A: Supernova Remnants and Neutron Stars

Q:
Are there any nearby stars that could explode and threaten our existence?

A:
Probably not. For a supernova to do real damage on Earth, it probably has to occur at a distance of less than about fifty light years. All such nearby stars are of sufficiently low mass (less than about ten times the mass of the Sun) that they will very likely lose enough of their mass in their red giant phase and turn into white dwarf stars without an explosion. Spica, the brightest star in Virgo, has a mass of about ten times the Sun, and will probably explode as a supernova in several million years, but it is 260 light years away. Celestial fireworks can also be expected from Antares in Scorpius at a distance of 390 light years and Betelgeuse in Orion, 500 light years away.