Deep Sky Astronomy & Telescopes

Gaia: Early Views, Big Prospects

February 18, 2014

We have several months yet before the European Space Agency’s Gaia mission enters its five-year operational phase. But you can see an important milestone in the image below. Gaia’s two telescopes have to be aligned and focused as its other instruments are calibrated. Testing involves downloading data like this image of NGC1818, a young star […]

Read the full article →

An Intergalactic River of Hydrogen?

January 28, 2014

NGC 6946, the so-called ‘Fireworks Galaxy,’ has caught the eye of many an astronomer, even if its position — close to the plane of the Milky Way and thus partially obscured by gas and dust — makes the observation difficult. At 22 million light years from Earth, this face-on spiral galaxy has been the site […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →

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 […]

Read the full article →