Exoplanetary Science

Night and Day on β Pictoris b

April 30, 2014

Writing yesterday about Kevin Luhman’s discovery of another cold brown dwarf in the stellar neighborhood reminded me of work we discussed earlier this year in which the weather on the surface of Luhman 16 B was mapped. This was done using the European Southern Observatory’s Very Large Telescope (see Focus on the Nearest Brown Dwarfs), […]

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Luhman’s Latest: A New, Nearby Brown Dwarf

April 29, 2014

Kevin Luhman (Pennsylvania State University) has focused much of his research on the formation of low-mass stars and brown dwarfs in star-forming regions near the Sun. This involves working with relatively young stars, but Luhman is also on the alert for older objects, very cool brown dwarfs in the solar neighborhood. Brown dwarfs cool over […]

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55 Cancri A: Stable Orbital Solutions

April 24, 2014

We’re developing a model for the fascinating planetary system around the binary star 55 Cancri, a challenging task given the complexity of the inner system in particular. What we have here is a G-class star around which five planets are known to orbit and a distant M-dwarf at over 1000 AU. Have a look at […]

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Enter the ‘Anti-Transit’

April 22, 2014

Gravitational lensing is a technique rich enough to help us study not only distant galaxies but exoplanets around stars in our own Milky Way. As gravity warps space and time, light passing near a massive object takes the shortest route, from our perspective seeming to be bent by the gravitational field. Inside the Milky Way, […]

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Two Takes on Habitability

April 21, 2014

Last week’s announcement about Kepler-186f presented a world that is evidently in the outer reaches of its star’s habitable zone, with the usual caveats that we know all too little about this place to draw any conclusions about what is actually on its surface. Is it rocky, and does it have liquid water? Perhaps, but […]

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A Tantalizing Exomoon Possibility

April 10, 2014

Gravitational microlensing is a phenomenally interesting way to find unusual things in the cosmos. A closer star can bend space around itself enough that, when it passes between us and a more distant star, a distinct brightening of the distant star’s light is apparent, a lens effect. That’s a useful phenomenon in its own right, […]

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Habitability: The Case for F-Class Stars

March 27, 2014

When it comes to habitable planets, we focus naturally enough on stars like our own. But increasing attention has been paid to stars smaller and cooler than the Sun. M-class dwarfs have small but interesting habitable zones of their own and certain advantages when it comes to detecting terrestrial planets. K-class stars are also interesting, […]

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Imaging Beta Pictoris b

March 25, 2014

This morning I want to circle around to a story I had planned to write about a couple of weeks ago. One thing writing Centauri Dreams has taught me is that there is never a shortage of material, and I occasionally find myself trying to catch up with stories long planned. In this case, the […]

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Measuring Atmospheric Pressure on Exoplanets

March 6, 2014

We haven’t talked much in these pages about atmospheric pressure when it comes to characterizing exoplanets, but recent discussions of ‘super-Earths’ and thick, hydrogen/helium atmospheres have raised the issue. All but simultaneously came the news of a paper from Amit Misra (a University of Washington graduate student) and co-authors describing a new way of detecting […]

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Red Dwarfs: Planets in Abundance

March 5, 2014

Whether or not they’re suitable for life, habitable zone ‘super-Earths’ are seeing increased scrutiny around M-class dwarf stars because the mass ratio of planet to star makes detection easier than around more massive stars. We need radial velocity surveys to help us here because planets on orbits longer than 200-300 days will definitely be out […]

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