“Super-Puff” Exoplanets Aren’t Like Anything We’ve Got in the Solar System

Artist's impression of the Kepler 51 system. Credits: NASA, ESA, and L. Hustak, J. Olmsted, D. Player and F. Summers (STScI)

The study of extrasolar planets has really exploded in recent years. Currently, astronomers have been able to confirm the existence of 4,104 planets beyond our Solar System, with another 4900 awaiting confirmation. The study of these many planets has revealed things about the range of possible planets in our Universe and taught us that there are many for which there are no analogs in our Solar System.

For example, thanks to new data obtained by the Hubble Space Telescope, astronomers have learned more about a new class of exoplanet known as “super-puff” planets. Planets in this class are essentially young gas giants that are comparable in size to Jupiter but have masses that are just a few times greater than that of Earth. This results in their atmospheres having the density of cotton candy, hence the delightful nickname!

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ESA’s CHEOPS Just Launched. We’re About to Learn a LOT More About Exoplanets

The ESA's CHEOPS launching aboard a Soyuz-FG rocket from Kourou, French Guiana. Image Credit: ESA - S. Corvaja

The CHEOPS mission is underway. On December 18th, the exoplanet-studying spacecraft launched from Europe’s Spaceport in Kourou, French Guiana aboard a Soyuz-Fregat rocket. Initial signals from CHEOPS show that the launch was a success.

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Without a Magnetosphere, Planets Orbiting Flare Stars Don’t Stand a Chance

superflare
An artist's conception of a superflare event, on a dwarf star. Image credit: Mark Garlick/University of Warwick

Earthlings are fortunate. Our planet has a robust magnetic shield. Without out magnetosphere, the Sun’s radiation would’ve probably ended life on Earth before it even got going. And our Sun is rather tame, in stellar terms.

What’s it like for exoplanets orbiting more active stars?

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Science Fiction Might Be Right After All. There Might Be Breathable Atmospheres Across the Universe

This view of Earth’s horizon was taken by an Expedition 7 crewmember onboard the International Space Station, using a wide-angle lens while the Station was over the Pacific Ocean. A new study suggests that Earth's water didn't all come from comets, but likely also came from water-rich planetesimals. Credit: NASA
This view of Earth’s horizon was taken by an Expedition 7 crewmember onboard the International Space Station, using a wide-angle lens while the Station was over the Pacific Ocean. A new study suggests that Earth's water didn't all come from comets, but likely also came from water-rich planetesimals. Credit: NASA

The last few years has seen an explosion of exoplanet discoveries. Some of those worlds are in what we deem the “habitable zone,” at least in preliminary observations. But how many of them will have life-supporting, oxygen-rich atmospheres in the same vein as Earth’s?

A new study suggests that breathable atmospheres might not be as rare as we thought on planets as old as Earth.

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These Incredible Images of Alien Worlds are Actually Miniatures

View from an alien moon by Adam Makarenko. Image Copyright: Adam Makarenko

Have you heard of Adam Makarenko? No?

Adam is an artist who makes physical models of exoplanets then creates elaborate photo shoots of them. Adam is our new favorite Instagram feed at Universe Today, and he even took over the UT Instagram feed recently.

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Neptune-Sized Planet Found Orbiting a Dead White Dwarf Star. Here’s the Crazy Part, the Planet is 4 Times Bigger Than the Star

Astronomers have found a white dwarf star which appears to be surrounded by a truncated disc of gas. The disc was probably created from a gas planet being torn apart by its gravity.

Astronomers have discovered a large Neptune-sized planet orbiting a white dwarf star. The planet is four times bigger than the star, and the white dwarf appears to be slowly destroying the planet: the heat from the white dwarf is evaporating material from the planet’s atmosphere, forming a comet-like tail.

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Of the Two Stars in Alpha Centauri, One is Probably More Habitable than the Other

Artist's impression of a hypothetical planet orbiting the star Alpha Centauri B, a member of the triple star system that is the closest to Earth. Credit: ESO

In the past, the number of known exoplanets has exploded, with 4093 confirmed detections so far (and another 4,727 candidates awaiting confirmation). With the discovery of so many planets that are dozens, hundreds, or even thousands of light years away, a great deal of attention has understandably been directed to our nearest stellar neighbors. Could planets be right next door, with the possibility of life being there as well?

While a potentially-habitable planet was recently discovered around Proxima Centauri (Proxima b), Alpha Centauri remains something of a question mark. But thanks to a recent study from the Georgia Institute of Technology (GIT), we might be getting closer to determining if this neighboring system supports life. In a twist, the study revealed that one of the stars in the binary system is more likely to be habitable than the other.

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How Large Can A Planet Be?

How big can a planet be? Credit: NASA/JPL-Caltech

Jupiter is the largest planet in the solar system. In terms of mass, Jupiter towers over the other planets. If you were to gather all the other planets together into a single mass, Jupiter would still be 2.5 times more massive. It is hard to understate just how huge Jupiter is. But as we’ve discovered thousands of exoplanets in recent decades, it raises an interesting question about how Jupiter compares. Put another way, just how large can a planet be? The answer is more subtle than you might think.

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Tatooines everywhere? Many of the Exoplanets Already Discovered are in Multi-Star Systems

These images show some of the exoplanet host stars with companion stars (B, C) that were found during the project. The images are RGB composite images taken with the Panoramic Survey Telescope and Rapid Response System (PanSTARRS) in the y- (960 nm), i- (760 nm), and g-band (480 nm). The image in the middle shows a hierarchical triple star system. Image: Mugrauer, PanSTARRS

Right now, we know of about 4,000 confirmed exoplanets, mostly thanks to the Kepler mission. TESS, the Transiting Exoplanet Survey Satellite, will likely raise that 4000 by a lot. But what about the stars that all of these planets orbit?

A new study from the Astrophysical Institute and University Observatory of the University of Jena identified over 200 exoplanets that exist in multiple star systems. The study is part of the effort to understand how host stars shape the formation and evolution of planets.

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TESS Has Now Captured Almost the Entire Southern Sky. Here’s a Mosaic Made of 15,347 Photographs

Credit: NASA

On April 18th, 2018, NASA’s Transitting Exoplanet Survey Satellite (TESS) took to space for the first time. By August, it began capturing the light curves of distant stars for signs of planetary transits, effectively picking up where the Kepler Space Telescope left off. Now, just a few months away from the end of its primary mission, NASA has put a year’s worth of images of the southern sky together to create the beautiful mosaic you see here.

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