(July 16, 2015) Sibling suns – made famous in the “Star
Wars” scene where Luke Skywalker gazes toward a double sunset – and the planets
around them may be more common than we’ve thought, and Cornell astronomers are
presenting new ideas on how to find them.
Astronomers could discover a plethora of planets around
binary star systems (stars that rotate around each other) by measuring with
high precision how stars move around each other, looking for disturbances
exerted by possible exoplanets. So explains new research, “Survival of Planets
Around Shrinking Stellar Binaries,” published in the Proceedings of the
National Academy Sciences, July 9, by Diego J. Munoz, Cornell postdoctoral researcher,
and Dong Lai, professor of astronomy, in the College of Arts and Sciences.
What once was fictional as young Skywalker saw the double
suns from Tatooine is astronomical reality four decades later. Normal binary
suns orbit each other every eight to 100 days, and the Kepler telescope easily
can detect those exoplanets (planets outside of our own solar system) as the
planets transit (move across) each sun.
Trouble starts in compact binary sun systems – where sibling
suns move closer together – making it difficult for the most advanced
telescopes to find them. Essentially, for Kepler and other telescopes, the
planetary orbital plane of these double suns and their accompanying planets might
be out of whack – or misaligned – rendering them invisible to us. “The current
observational strategy inevitably misses a population of Tatooine planets, but
future observations may reveal their existence,” said Munoz.