Hubble Discovers 'Planetary Graveyard' Around White Dwarf
astroengine send this interesting excerpt from Discovery: "The Hubble Space Telescope has discovered rocky remains of planetary material 'polluting' the atmospheres of two white dwarfs — a sign that these stars likely have (or had) planetary systems and that asteroids are currently being shredded by extreme tidal forces. Although white dwarfs with polluted atmospheres have been observed before, this is the first time evidence of planetary systems have been discovered in stars belonging to a relatively young cluster of stars. 'We have identified chemical evidence for the building blocks of rocky planets,' said Jay Farihi of the University of Cambridge in a Hubble news release. 'When these stars were born, they built planets, and there's a good chance that they currently retain some of them. The signs of rocky debris we are seeing are evidence of this — it is at least as rocky as the most primitive terrestrial bodies in our Solar System.'"
It says a relatively young cluster of stars. That doesn't mean that some members of the cluster aren't old enough to have gone nova. Also, larger hotter stars (than the Sun) don't stay in the main sequence nearly as long, so it's possible that some were just under the threshold to become neutron stars. There is no contradiction there.
These white dwarfs are only 150 light years away. So if any life managed to get off planet and spread out we would have noticed the resulting civilization. We'll probably never know for sure if there was life or even intelligent life on any of these planets because they've been so torn apart by the tidal forces (and very likely anything left on them died out millions of years ago). I wonder if in a few billion years, there might be some other nearby just beginning race looking out to the remains of our solar system and reaching very similar conclusions.
... we've come out of hyperspace into a meteor shower. Some kind of asteroid collision. It's not on any of the charts.
Spare parts to keep our planet running longer!
Have gnu, will travel.