Deep Sky Astronomy & Telescopes

Looking at Gaia’s Sky

September 15, 2016

The European Space Agency’s Gaia satellite has delivered a catalog of more than a billion stars — 1142 million, to be more specific — as it continues the work of mapping our galaxy in three dimensions. To be sure, we can expect much more from Gaia, but the September 14 data release is a milestone, […]

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Brown Dwarf Analysis Offers Exoplanet Implications

August 16, 2016

Brown dwarfs offer exciting prospects for exoplanet work. Not only are we learning that they can have planets of their own, but brown dwarfs themselves are a useful bridge between planets and stars. We also know that there are a lot of them out there. According to data from the WISE (Wide-field Infrared Survey Explorer) […]

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KIC 8462852: Fading in the Kepler Data

August 5, 2016

Those of you who have been following the controversy over the dimming of KIC 8462852 (Tabby’s Star) may remember an interesting note at the end of Bradley Schaefer’s last post on Centauri Dreams. Schaefer (Louisiana State University) had gone through his reasoning for finding a long-term dimming of the star in the DASCH (Digital Access […]

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An Unusual Pulsating Binary

July 29, 2016

A large part of the fascination of astronomy is the discovery of objects that don’t fit our standard definitions. KIC 8462852 — ‘Tabby’s Star’ — is deeply mysterious and high on my watchlist. But yesterday we also looked at CX330, a so-called FUor of the kind that brightens enormously over years of observation. Today we […]

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CX330: Distant (and Isolated) Star Formation

July 28, 2016

Given that we have fewer than a dozen examples, highly variable stars like the recently discovered CX330 have much to teach us. These stars have been nicknamed FUors, after FU Orionis, a pre-main sequence star that has shown huge variations in magnitude over the past century. Eruptions like these may be common, as Alan Boss […]

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Into the Nebula: Low-Mass Objects in Orion

July 12, 2016

Because we want to learn more about how stars form, we study the so-called Initial Mass Function, which tells us, for a given population of stars, the distribution of their initial masses. As one recent reference (the Encyclopedia of Astrobiology, Springer, 2011) puts it: “The initial mass function is the relative number of stars, as […]

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Calibrating Distances to Low Mass Stars

June 30, 2016

Accurate distances are critical for understanding the physical properties of brown dwarfs and low-mass stars. We need to know the intrinsic brightness of these objects to proceed, but we can’t know that until we have an idea of their distance. After all, a relatively faint star can seem much brighter if nearer to us, while […]

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Deep Stare into a Dusty Universe

June 29, 2016

It’s not often that I get the chance to back up and take a broad look at the universe, the kind of thing that reinforces my interest in cosmology and structure at the grandest scale. But today I’ll take my cue from the Royal Astronomical Society’s annual meeting, now underway in Nottingham UK, which gives […]

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Toward Gravitational Wave Astronomy

June 20, 2016

The second detection of gravitational waves by the LIGO (Laser Interferometer Gravitational-Wave Observatory) instruments reminds us how much we gain when we move beyond the visible light observations that for so many millennia determined what people thought of the universe. In the electromagnetic spectrum, it took data at long radio wavelengths to show us the […]

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Supernova at Twilight

April 6, 2016

In his novel The Twilight of Briareus (John Day, 1974), Richard Cowper, who in reality was John Middleton Murry, Jr., wrote about a fictitious star called Delta Briareus that goes supernova (true, there is no constellation called Briareus, but bear with me). Because it is only 130 light years out, the supernova showers the Earth […]

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