Exoplanetary Science

Chemical Change in a Protoplanetary Disk

February 19, 2014

The young star known as L1527 offers a spectacular view at infrared wavelengths, a result of the configuration of gas and dust around it. Have a look at the image below, taken by the Spitzer Space Telescope, where light from the star escapes through the opening provided by a bipolar gas flow, illuminating the gas […]

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Unusually Red Brown Dwarfs (and What They Tell Us)

February 11, 2014

As we continue to learn more about brown dwarf atmospheres, the dwarf ULAS J222711-004547 catches the eye because of its unusually red appearance. What Frederico Marocco (University of Hertfordshire) and team have learned through observations with the Very Large Telescope in Chile is that a thick layer of clouds in the upper atmosphere is responsible […]

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Kepler-413b: Wobbles of a Circumbinary World

February 10, 2014

It was always a good bet that we’d get plenty of surprises as data from Kepler began to come in, but the odd world known as Kepler-413b really does stand out. The transit method seems made to order for a certain regularity — Kepler looks at how the light from a given star dims when […]

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Thoughts on Planetary Migration

February 6, 2014

Learning that liquid water may exist beneath the surface of more than a few Solar System objects naturally raises astrobiological questions. But as Caleb Scharf notes in Water Erupts Across the Solar System, a much larger issue is whether the kind of chemoautotrophic microbes we find on Earth (Scharf calls them ‘rock eaters’) could have […]

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Alpha Centauri: Dust and Its Significance

February 5, 2014

When I was growing up, Alpha Centauri was utterly dismissed as a possible location for planets. A binary system couldn’t possibly produce them, I read, and it was assumed that planets could only be found around single stars like our own Sun. How times have changed. Now we know of plenty of multiple star systems […]

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Focus on the Nearest Brown Dwarfs

January 29, 2014

Luhman 16AB (otherwise known as WISE J104915.57-531906) holds out quite an allure for those of us hoping to see future exploratory missions to nearby interstellar space. As recounted here in December (see Possible Planet in Nearby Brown Dwarf System), the European Southern Observatory’s Henri Boffin has found that this brown dwarf pair is likely home […]

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What Makes a Planet ‘Superhabitable’?

January 27, 2014

Friday’s look at habitable zones, and the possibilities of life below the surface or in the atmosphere of an exoplanet, segues naturally into the fascinating notion of ‘superhabitable’ worlds. René Heller (McMaster University) and John Armstrong (Weber State University) ponder the possibilities in a recent paper for Astrobiology. What if, the scientists ask, our notions […]

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Astrobiology Underground

January 24, 2014

I’m a great believer in what I might call the ‘conventional’ habitable zone; i.e., a habitable zone defined by the possibility of liquid water on the surface. The definition is offered not to exclude exotic possibilities like micro-organisms floating in the clouds of Venus or aquatic life deep inside an ice-covered moon like Europa. Rather, […]

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HD 142527: An Unusual Circumstellar Disk

January 22, 2014

Conventional models of planet formation involve core accretion, where dust grains accumulate into protoplanets whose subsequent collisions and interactions produce planets, or gravitational instability, involving a rapid collapse from dense disk debris into a planetary core. But how far from the parent star does planet formation occur? The more we learn about protoplanetary disks, the […]

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‘Cluster Planets’: What They Tell Us

January 15, 2014

2500 light years from Earth in the constellation of Cancer lies Messier 67, an open star cluster that is now known to be home to at least three planets. The new worlds, found using the HARPS spectrograph on the European Southern Observatory’s 3.6-meter instrument at La Silla, come as the result of an observation program […]

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