(Submitted September 14, 2000)
I have just read that our solar system was likely formed from the
effects of an earlier supernova. Does this mean that there should be
some residual object like a neutron star (or even a black hole)
somewhere in the neighborhood?
Thank you for your question. There indeed is some speculation that the
compression of Giant Molecular Clouds by supernova explosions is instrumental
in causing these clouds to collapse and form stars and solar systems
(such as our own). This is called stochastic star formation, and is
thought to cause the "starburst" regions seen in other galaxies.
Any ancient remnant from such an explosion would be quite inconspicuous.
Solitary black holes are practically unobservable, as are isolated old
neutron stars (young neutron stars may shine as pulsars). They could
continue to shine by proxy if they were encircled by hot disks of gas
continually fed by a binary companion, but it may be difficult for such
systems to remain intact after the explosion.
Any such object is unlikely to still be in our neighborhood anyway.
The Sun has orbited the center of our galaxy a couple of dozen times
or so since it was formed and any object nearby at that time that is
not bound to the Sun (as the Earth is) is extremely unlikely to be
nearby now. Moreover, the explosion might have imparted a high speed
to the collapsed remnant so that it is not even in its original
We're afraid the chances of identifying the culprit are rather remote.
-- Michael Loewenstein and David Marsden
for "Ask an Astrophysicist"