Exoplanetary Science

Binary Stars: The Likelihood of Planets

September 10, 2014

In Greg Bear’s novel Queen of Angels (Gollancz, 1990), a robotic probe called AXIS (Automated eXplorer of Interstellar Space) has used antimatter propulsion to make a fifteen-year crossing to Alpha Centauri. The world’s various networks of the future begin to feast on reports of what it finds, like this one: “In the past few weeks, […]

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Red Dwarf Planets: Weeding Out the False Positives

September 3, 2014

For those of you who, like me, are fascinated with red dwarf stars and the prospects for life around them, I want to mention David Stevenson’s Under a Crimson Sun (Springer, 2013), with the caveat that although it’s on my reading list, I haven’t gotten to it yet. More about this title after I’ve gone […]

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Radio Emissions: An Exomoon Detection Technique?

August 13, 2014

Here’s an interesting notion: Put future radio telescopes like the Long Wavelength Array, now under construction in the American southwest, to work looking for exomoons. The rationale is straightforward and I’ll examine it in a minute, but a new paper advocating the idea homes in on two planets of unusual interest from the exomoon angle. […]

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Keeping a Planet Alive

August 6, 2014

I’ve made no secret of my interest in red dwarf stars as possible hosts of life-bearing planets, and this is partially because these long-lived stars excite visions of civilizations that could have a stable environment for many billions of years. I admit it, the interest is science fictional, growing out of my imagination working on […]

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HK Tauri: Misaligned Protoplanetary Disks

July 30, 2014

When I was a boy in ninth grade, I asked our science teacher whether the nearest star was likely to have planets. He loved the question because it gave him the chance to explain to the class that Alpha Centauri was a binary star (we left poor Proxima out of the discussion), and that as […]

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‘Hot Jupiters’: Drier Than Expected

July 29, 2014

Be aware of Open Source, a radio show on Boston’s WBUR that last week did a show about exoplanets and the possibility of extraterrestrial life. Earth 2.0 is available online, featuring David Latham (Harvard-Smithsonian Center for Astrophysics), Dimitar Sasselov (Harvard University), Jason Wright (Penn State) and Sarah Rugheimer (a PhD student at Harvard studying exoplanet […]

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Tight Measurement of Exoplanet Radius

July 28, 2014

Both the Kepler and Spitzer space telescopes had a role to play in recent work on the planet Kepler-93b, whose size is now known to an uncertainty of a mere 120 kilometers on either side of the planet. What we have here is the most precise measurement of an exoplanet radius yet, a helpful result […]

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Transiting World at the Snow Line

July 23, 2014

It’s 9000 times easier to find a ‘hot Neptune’ than a Neptune out around the ‘snow line,’ that region marking the distance at which conditions are cold enough for ice grains to form in a solar system. Thus says David Kipping (Harvard-Smithsonian Center for Astrophysics), who is lead author on the paper announcing the discovery […]

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Kepler-56: Misaligned Planets Around a Swelling Star

June 6, 2014

Although I’m sure I’ll refer to various papers presented at the American Astronomical Society this week in future entries, I’ll close our current look at the Boston meeting with word of two planets that will be falling into their star in short order (at least as astronomers measure time). Kepler-56b and Kepler-56c have a predicted […]

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Three Regimes of Planet Formation

June 5, 2014

On Tuesday I mentioned the work of Lars A. Buchhave, an astronomer at the Harvard-Smithsonian Center for Astrophysics (CfA), in connection with the Kepler-10c discovery. The latter is the so-called ‘mega-Earth’ now found to be seventeen times as massive as our own planet, with a diameter of about 29,000 kilometers. A larger population of solid […]

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