50 new orbs join the list of the 645 planets we’ve discovered beyond our solar system
If you’re not impressed by planets made of diamond and stars cooler than the human body, maybe the newest landmark space find will strike your fancy. Astronomers have just discovered a stash of more than 50 new exoplanets — the largest single discovery of its kind to date. While the Kepler space telescope previously spotted over one thousand planets, those were only candidates for planetdom — many of them likely won’t make the cut.
Unlike NASA’s Kepler spacecraft, which watches for the shadows of possible planets as they cross in front of sun-like stars, the High Accuracy Radial velocity Planetary Search (HARPS) spotted this handful of new planets with a different technique entirely. HARPS is a spectrograph, a piece of equipment that (as Bad Astronomy explains) “takes light from distant objects and breaks it down into incredibly thin slices of wavelength, like a rainbow with a hundred thousand colors.”
In the course of orbiting a star, planets create a gravitational pull that can be viewed by instruments like the HARPS. The spectrograph can pick up on these extremely subtle shifts in the star’s color: a red shift would signal that the star is being tugged away from us, while a blue shift is the opposite — and both occur during a planet’s orbital path around a sun-like star. These spectrum shifts are how astronomers can infer the existence of a planet as it sneaks around a star many light years away from Earth.
The HARPS researchers found the new planets while surveying 376 stars that resemble our own sun. Out of the 50 new planets, 16 qualify as super-Earths: planets with a mass bigger than Earth’s, but not nearly as high as Jupiter or Saturn. These super-Earths orbit sun-like stars and tend to be habitable planet candidates, since their conditions most resemble those we know to support life.
Happily, the group behind the HARPS findings is working on a new exoplanet-hunter — a spectrograph known as the Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO). ESPRESSO is set to begin scanning the skies for planets in 2016. Since the new spectrograph is substantially more powerful than HARPS, it could spot planets that are closer to Earth’s own size — interstellar bodies that have more in common with our own planet than we’ve ever seen before.
[Image credit: ESO]
This article originally appeared on Tecca
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