Exoplanetary Science

Structure and Composition of a White Dwarf Planet

June 16, 2016

Given everything we’re learning about planets around other suns, it’s frustrating that we have so little information about the chemical composition of the rocky planets we’ve found thus far. Now we have a new study, announced at the San Diego meeting of the American Astronomical Society, that offers data on a ‘planet-like body’ whose surface […]

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A Long-Period Circumbinary World

June 15, 2016

Before getting into today’s subject, the discovery of an interesting long-period circumbinary planet, I want to make another pitch for Centauri Dreams readers to support the Kickstarter campaign for Tabby’s Star. I’ve written often about this mysterious star whose light curves are anomalous and demand further study. Trying to find out what’s happening around KIC […]

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Hot Jupiters: The Missing Water Vapor

June 9, 2016

In late 2015, an international team led by David Sing (University of Exeter, UK) studied ten ‘hot Jupiters’ to try to figure out why some of these planets have less water in their atmospheres than expected from earlier modeling. Sing and company were working with transmission spectroscopy, possible when a planet transits its star and […]

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In Search of Carbon Planets

June 8, 2016

The first generation of stars in the universe began to shine in an era when chemical elements like carbon and oxygen were not available. It was the explosion of these early stars in supernovae that began the process of enrichment, with heavier elements fused in their cores now spreading into the cosmos. Lower-mass stars and […]

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Kepler-62f: Models for Habitability

May 27, 2016

So often planets described as ‘potentially habitable’ turn out to be over-rated — we look deeper into their composition and characteristics only to find that the likelihood of liquid water on the surface is slim. How to make more accurate calls on the matter of habitability? One way may be to combine orbital and atmospheric […]

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Looking for Life Around Red Giant Stars

May 19, 2016

I suppose the most famous fictional depiction of the Sun as it swells to red giant stage is in H. G. Wells’ The Time Machine, in a passage where the time traveler takes his device by greater and greater jumps into the remote future. This is heady stuff: I moved on a hundred years, and […]

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The Surface Gravity Plateau

May 12, 2016

What’s a movie director supposed to do about gravity? In The Martian, we see Matt Damon moving about on Mars with a gait more or less similar to what he would use on Earth, despite Mars’ 0.38g. Harrison Ford changes worlds but never strides in The Force Awakens. About the gravitational challenges of 1953’s Cat […]

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On Kepler’s 1284 New Planets

May 11, 2016

If you look into the software that made possible yesterday’s exoplanet results, you’ll find that VESPA (Validation of Exoplanet Signals using a Probabilistic Algorithm) is freely available online. The work of Princeton’s Timothy Morton, who spoke at the announcement news conference, VESPA is all about calculating the probabilities of false positives for signals that look […]

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TRAPPIST-1: Three Nearby Worlds

May 2, 2016

About forty light years from Earth in the constellation Aquarius is the star designated 2MASS J23062928-0502285, which as of today qualifies as perhaps the most interesting ultracool dwarf we’ve yet found. What we learn in a new paper in Nature is that the star, also known as TRAPPIST-1 after the European Southern Observatory’s TRAPPIST telescope […]

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Light’s Echo: Protoplanetary Disk Examined

April 28, 2016

The star YLW 16B, about 400 light years from the Earth, has roughly the same mass as the Sun. But unlike the Sun, a mature 4.6 billion year old star, YLW 16B is a scant million years old, a variable of the class known as T Tauri stars. Whereas our star is relatively stable in […]

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