Deep Sky Astronomy & Telescopes

A Brown Dwarf Benchmark

January 21, 2014

Couple the Keck I 10-meter telescope on Mauna Kea with HIRES (the High-Resolution Echelle Spectrometer) and you get extremely high spectral resolution, making the combination a proven champion at finding planets around other stars. But it was when Justin Crepp (University of Notre Dame) and team followed up seventeen years of HIRES measurements with new […]

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Cloudy Encounter at the Core

January 13, 2014

The supermassive black hole at the center of our galaxy comes to Centauri Dreams‘ attention every now and then, most recently on Friday, when we talked about its role in creating hypervelocity stars. At least some of these stars that are moving at speeds above galactic escape velocity may have been flung outward when a […]

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Stars at Galactic Escape Velocity

January 10, 2014

How do you boost the velocity of a star up to 540 kilometers per second? Somewhere in that region, with a generous error range on either side, is the speed it would take to escape the galaxy if you left from our Solar System’s current position. Here on Centauri Dreams we often discuss exotic technologies […]

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Brown Dwarfs at the Boundary

December 10, 2013

We spend a lot of time probing the borderlines of astronomy, wondering what the boundaries are between a large gas giant and a brown dwarf, for example. The other end of that question is also intriguing: When does a true star get small enough to be a brown dwarf? For main sequence stars don’t operate […]

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Ancient Brown Dwarfs Discovered

November 21, 2013

How many brown dwarfs should we expect in the Milky Way? I can recall estimates that there could be as many brown dwarfs as main sequence stars back when people started speculating about this, but we have to go by the data, and what we have so far tells another tale. The WISE (Wide-field Infrared […]

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Views of Proxima Centauri

November 4, 2013

I haven’t yet read Stephen Baxter’s new novel Proxima, but because of my admiration for his previous books, it’s at the top of my reading list. Judging from the Amazon description, Proxima gets into issues that for me make red dwarfs utterly compelling. What would a habitable planet look like around such a star, tidally […]

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Interstellar Wanderers

October 10, 2013

Because of my fascination with exotic venues for astrobiology, I’ve always enjoyed Karl Schroeder’s novels. The Canadian writer explored brown dwarf planets as future venues for human settlement in Permanence (2002), and in his new book Lockstep (soon to be published by Tor, currently being serialized in Analog), Schroeder looks at ‘rogue’ planets, worlds that […]

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Hunting for Brown Dwarf Planets

April 30, 2013

Brown dwarfs fascinate me because they’re the newest addition to the celestial menagerie, exotic objects about which we know all too little. The evidence suggests that brown dwarfs can form planets, but so far we’ve found only a few. Two gravitational microlensing detections on low mass stars have been reported, one of which is a […]

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The Alpha Centauri Angle

April 25, 2013

Apropos of yesterday’s article on the discovery of Proxima Centauri, it’s worth noting that Murray Leinster’s story “Proxima Centauri,” which ran in Astounding Stories in March of 1935, was published just seven years after H. A. Alden’s parallax findings demonstrated beyond all doubt that Proxima was the closest star to the Sun, vindicating both Robert […]

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Finding Proxima Centauri

April 24, 2013

It’s fascinating to realize how recent our knowledge of the nearest stars has emerged. A little less than a century has gone by since Proxima Centauri was discovered by one Robert Thorburn Ayton Innes (1861-1933), a Scot who had moved to Australia and went on to work at the Union Observatory in Johannesburg. Innes used […]

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