Giant ‘Mirror’ Planets Found in First-of-Its-Kind Experiment – By Nadia Drake NatGeo PUBLISHED JUNE 22, 2017


If confirmed, the shiny new worlds may help astronomers better understand how strange planets known as hot Jupiters are created.

Picture of a hot jupiter

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An illustration shows a hot Jupiter, a type of planet that is about the same size as our solar system’s largest world but is bizarrely close to its host star.

Photograph by NASA, JPL, Caltech

MOUNTAIN VIEW, CaliforniaPlanets orbiting other stars are running out of ways to hide.

For the first time, astronomers have used reflected starlight to tease out the possible presence of 60 large, roasted worlds. As those planets traipse around their stars, they act like large alien mirrors and briefly bounce a bit of extra starlight toward Earth, causing a small but measurable increase in their systems’ brightness.

The discoveries still need to be independently confirmed using a different planet-hunting method. But if even some of the worlds are really there, they could have an important story to tell about how such hot, Jupiter-size planets form.

“You see a brightening when the planet moves behind the star because at that point, you’re seeing its day side,” says Yale University graduate student Sarah Millholland, who will present the work Friday at the Kepler and K2 Science Conference.

 

Solar System 101 How was our solar system born? Join scientists as they embark on a journey into the mesmerizing mysteries of space. Hear their expert theories, then decide for yourself.

The 60 possible planets were hiding among nearly 200,000 stars in the patch of sky that NASA’s Kepler spacecraft stared at for four years. Though the spacecraft has spotted more than 2,300 confirmed worlds among those stars, it can’t see all of the ones that must exist.

That’s because the probe orbits the sun, and distant planetary systems ordinarily need to be aligned just right so that planets pass between their stars and the spacecraft. Kepler can then detect a planet as it briefly blots out a portion of its star’s light. However, this configuration only occurs for about 10 percent of hot Jupiters.

“With the transit method, we’re still biased to systems that are aligned in a particular way, which means we don’t have the ability to explore the vast majority of planets in the galaxy,” says Caltech’s Courtney Dressing. “Sarah has found a way to identify more planets, even those in systems that are misaligned.”

The catch: Those planets need to be either really big, or really shiny.

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Astronomers Don’t Think That So-Called SETI Signal Is Aliens—and Neither Should You – SARAH SCOLES. 08.30.16. 3:33 PM


This weekend, a group of astronomers made many, many headlines after giving a presentation about “a strong signal in the direction of HD164595.” HD164595 is a Sun-like star 94 light-years away, and with the RATAN-600 radio telescope in Zelenchukskaya, Russia, pointed in its direction, the astronomers picked up a blast of radio waves about 4.5 times stronger than background static. Maybe aliens? they suggested. We should investigate.

Their presentation began circulating among astronomers in slide-deck form. Paul Gilster at the website Centauri Dreams wrote about it as “an interesting SETI candidate”—meaning perhaps it came from an extraterrestrial civilization. That set off the media storm.

But I have to tell you something: Astronomers don’t know much about that “SETI candidate” signal beyond that it’s made of radio waves. And while human beings should absolutely spend some time figuring out what this signal is, they have almost no reason to conclude it came from non-human beings. Here’s why:

They don’t actually know it’s coming from that star.

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