New Planet Found: Could a Super-Earth plus Triple Stars Equal Life
The search for exoplanets, or worlds
orbiting other stars, is evolving so fast that discoveries that seemed
exotic just a few months ago have become commonplace. Multiple-planet
solar systems? Astronomers expected to find just a handful; now we know
of more than 200. Planets orbiting double or even triple stars? It was
big news when just one was announced back in September; we've already
got several more examples in hand. In short, the unexpected is something
planet hunters have learned to expect — and in most cases, these
surprises have tended to expand the possibilities for finding worlds
where life might thrive.
It's just happened again: astronomers from the Carnegie Institution
of Washington and the University of California, Santa Cruz, writing in
the Astrophysical Journal Letters, have announced the discovery
of yet another new world that defies everyone's expectations. Not only
does the new planet orbit one of the suns in a triple-star system — rare
enough in itself — but the stars in this system have surprisingly low
levels of the heavy elements planets are made from. Theory suggests that
such stars shouldn't form planets in the first place, so if this isn't a
fluke, there may be many more planets in the Milky Way than anyone
thought.
