Astronomers have a brown dwarf problem. They should be seeing a lot more of these objects, which are cooler than stars but hotter than planets. Yet, there have only been about 40 directly imaged over the past few decades. Why aren’t astronomers finding more of them? It helps to remember that brown dwarfs are dim, low-temperature objects. They don’t stand out in a crowded starfield. If they’re too close to their stars, the starlight hides them from our view. They’re much better observed in the infrared part of the electromagnetic spectrum. All these characteristics make hunting for them difficult.Continue reading “A New Technique Finds a Bundle of Brown Dwarfs”
Gravity is a funny force. The gravity of every given object technically impacts every other given object, though, in practice, large distance and small masses make those forces negligible for such interactions. But in some cases, especially when large groups are floating in empty space, gravity can still hold sway over considerable distances. Such is the case with a new pair of brown dwarfs found by astronomers at the Keck Observatory.Continue reading “Twin Brown Dwarfs Discovered, Orbiting one Another at Three Times the Distance From the Sun to Pluto”
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Brown dwarfs are strange things. They are in the middle ground between planets and stars. A star is defined as an object massive enough for hydrogen to fuse into helium into its core, while a planet is too small for core fusion to occur. It seems a simple distinction until you learn about fusion. Anything with a mass below about 13 Jupiters is too small for fusion to occur, and is thus a planet. If your mass is about about 80 Jupiters, then you can fuse helium and are therefore a star. But if your mass is between 13 and 80 Jupiters, things get interesting. You can’t fuse hydrogen to shine brightly, but you can fuse lithium into other elements. This is known as lithium burning. It doesn’t provide lots of energy, but it is technically nuclear fusion.Continue reading “Brown Dwarfs are Probably Much More Common in the Milky Way Than Previously Believed”
We tend to image planets as spheres. Held together by gravity, the material of a planet compresses and shifts until gravity and pressure reach a balance point known as hydrostatic equilibrium. Hydrostatic equilibrium is one of the defining characteristics of a planet. If a planet were stationary and of uniform density, then at equilibrium, it would be a perfect sphere. But planets rotate, and so even the largest planets aren’t a perfect sphere.Continue reading “Brown Dwarfs can Spin so Fast They Almost Tear Themselves Apart”
Zooniverse brings out the best of the internet – it leverages the skills of average people to perform scientific feats that would be impossible otherwise. One of the tasks that a Zooniverse project called Backyard Worlds: Planet 9 has been working on has now resulted in a paper cataloguing 525 brown dwarfs, including 38 never before documented ones.Continue reading “We Now Have a 3D Map of The 525 Closest Brown Dwarfs”
Brown dwarfs are the weird not-planets but not-stars in the universe, and astronomers have wondered for decades if their atmospheres are striped like Jupiter’s, or splotchy like the sun’s. A team of astronomers based at the University of Arizona used NASA’s TESS Observatory to find the answer: if you saw a brown dwarf for yourself, it would look more like a giant planet than a star.Continue reading “Astronomers see Swirling Weather on the Closest Brown Dwarf”
Brown dwarfs are interesting objects. They are generally defined as bodies massive enough to trigger the fusion of deuterium or lithium in their cores (and are thus not a planet) but too small to fuse hydrogen in their cores (and therefore not a star). They are the middle children of cosmic bodies.Continue reading “Brown dwarf discovered with a radio telescope for the first time”
Brown dwarfs are smallish objects sitting somewhere between stars and planets, making them notoriously hard to find. But a recent citizen science project aimed at finding the elusive Planet 9 has instead revealed a treasure trove of these oddities, right next door.Continue reading “Astronomers find 100 brown dwarfs in our neighborhood”
Brown dwarfs are in a tough spot. Not quite a star, not quite a planet, they occupy a place between gas giants and stars. They have more mass than gas giants like Jupiter, but not enough to ignite fusion and become a star.
But astronomers still study them. How could they resist?Continue reading “Astronomers Can Actually See the Clouds and Weather on Brown Dwarf 6.5 Light-Years Away”
In some ways, brown dwarfs are nature’s stellar oddballs. A lot of stars exhibit strange behaviour at different times in their evolution. But brown dwarfs aren’t even certain that they’re stars at all.
But that doesn’t mean astronomers don’t want to study and understand them.Continue reading “Astronomers Measure the Wind Speed on a Brown Dwarf for the First Time. Spoiler: Insanely Fast”