Tale of an orphaned planet
A telescope in Hawaii has detected a planet floating freely without a solar system 80 light years away. Its lack of a star is even more noteworthy as the planet is estimated to be very young.
The Pan-STARRS 1 (PS1) wide-field survey telescope on Haleakala, Maui recently picked up a faint heat signature 80 light years away from earth. Other telescopes on Hawaii confirmed the observation and reached the conclusion that the heat signature comes from a planet about six times the mass of jupiter, floating out there alone without a sun to orbit around. What’s especially interesting is that this planet is young; only 12 million years old. In planetary terms, that’s really young. If we were to make some really broad generalizations about the average lifespan of a planet, we could say that this one is about two months old in human terms. “We have never before seen an object free-floating in space that that looks like this. It has all the characteristics of young planets found around other stars, but it is drifting out there all alone,” explained team leader Dr. Michael Liu at the University of Hawaii. “I had often wondered if such solitary objects exist, and now we know they do.”
Many extrasolar planets have been discovered recently, and most of them have been identified by studying the dimming of their host star’s light as they pass in front of it, or alternatively by studying the star’s wobble as it interacts gravitationally with the planet. Only a handful have been directly imaged, as is the case with the new orphaned planet, which has been named PSO J318.5-22. “Planets found by direct imaging are incredibly hard to study, since they are right next to their much brighter host stars. PSO J318.5-22 is not orbiting a star so it will be much easier for us to study. It is going to provide a wonderful view into the inner workings of gas-giant planets like Jupiter shortly after their birth,” said Dr. Niall Deacon of the Max Planck Institute in Germany.
The PS1 telescope that discovered the planet
The planet was discovered while the PS1 telescope was looking for brown dwarfs; failed stars with too little mass to sustain a fusion reaction. The PS1 telescope is especially outfitted to look for brown dwarfs, with a particularly sensitive camera able to pick up the very faint reddish glow of the failed stars. PSO J318.5-22 stood out to the astronomers because it exhibited a glow redder than any known brown dwarfs.