Category: Stars in their eyes
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Why SETI will have missed any cost conscious ET civilizations
If we want to contact any of those other civilizations out there, we’ll need a beacon to send messages with. But what to build? Gregory Benford at the University of California Irvine and family (?) have done a cost/benefit analysis on the types of microwave generators out there that can produce the 10^17 W necessary…
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How alien Earths will reveal their secrets
The European Space Agency has set itself an ambitious goal: to recognise the biomarkers on Earth-like planets orbiting other stars. The first step in such an endeavour is work out to look for, which the goal that Lisa Kaltenegger at the Harvard-Smithsonian Center for Astrophysics in Cambridge and Franck Selsis at the Laboratoire d’Astrophysique de…
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Nanodiamonds lead to sharper images
Zap a diamond nanoparticle with laser light and it will fluoresce, emitting single photons if it is small enough. That makes nanodiamonds extremely useful, say Aurélien Cuche at the Université Joseph Fourier in Grenoble and pals. For a start, nanodiamonds are easily absorbed by cells, which allows them and the processes inside them to be…
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How supermassive black holes help galaxies evolve
It’s easy to imagine that our understanding of the way galaxies form and evolve is more or less complete. After all, we’ve been fitting missing pieces into the jigsaw at an alarming rate in recent years with all this data from WMAP etc about the structure of the early universe, a better understanding of the…
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The ultimate black hole size limit
We have a pretty good idea that a supermassive black hole is sitting at the center of our galaxy. By supermassive, astronomers mean about 6 millions times as massive as our sun. That’s pretty big by any standards but how big can black holes get Is there any limit to how big these monsters can…
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How to find another Earth
“We stand on a great divide in the detection and study of exoplanets,” says the Exoplanet Task Force on the arXiv today in describing their plan for finding another Earth orbiting another star. On one side of this divide are the hundreds of known massive exoplanets, they say. And on the other” lies the…
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The black hole at the center of our galaxy
Is there a supermassive black hole at the center our galaxy, asks Mark Reid from the Harvard Smithsonian Center for Astrophysics in Cambridge. There sure is and Reid gives a good account of the evidence to prove it. How can astronomers be so sure? The first evidence began to emerge in the 1950s when the…
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Solar systems like ours likely to be rarer than we thought
Astronomers, to their obvious delight, have discovered some 250 planetary systems beyond our own, many of them with curious properties. In particular, the discovery of several “hot Jupiters” gas giants that orbit close to their parent stars, challenges our theories of planet formation.The thinking is that gas giants can only form far away from stars…
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The weather on HD 189733b
Our old friend HD 189733b is in the news again this week. As a Jupiter-sized gaseous planet orbiting a yellow dwarf in the constellation of Vulpecula, HD 189733b has become one of the best studied exoplanets. The reason is that it’s relatively big and close to its sun, which shines through the atmosphere as the…
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Why red dwarfs could reveal first Earth-like planets
Red dwarfs are relatively common, cool stars that are less than half the size of the Sun. Because of their size, it should be easy to spot orbiting planets as they pass in front of the stars. For instance, a planet twice the size of Earth, orbiting in a star’s habitable zone at a distance…