an electron within a molecule gets excited to a higher-energy state, the electron de-transitions back to the lower energy state, where it emits light of a very specific wavelength in the process. Then, pumped or injected energy re-excites an electron within that very same molecule back into that higher-energy state, over and over.
Astronomers may have finally solved one of the weirdest mysteries of our night sky: why Betelgeuse, a massive star in the constellation Orion, seems to fade and brighten as if it were operated by a heavenly dimmer switch. Using the Hubble Space Telescope and ground-based observatories, scientists observed Betelgeuse for almost eight years and found that patterns in the star's light suggested the wake of another, unseen star was passing through its atmosphere.
Looking skyward fills us with wonder. Off-world, the Sun, planets, stars, and galaxies all await. Our Solar System encompasses our own cosmic backyard. Farther away, stars and star clusters abound within the Milky Way. Hundreds of billions of stars exist just within our home galaxy. Inside our Local Group, only Andromeda surpasses us in mass, size, and stars. More than 5 million light-years away, galaxies abound in groups and clusters.
A dead star 730 light years away appears to be forming a powerful structure around itself - and despite their best efforts, astronomers aren't sure how. The cosmic corpse, designated RXJ0528+2838, is an incredibly dense stellar remnant known as a white dwarf, with a Sun-like star orbiting around it. This binary arrangement isn't uncommon throughout the universe, but what is strange is the structure surrounding the former body: a highly energetic and luminescent cloud known as a nebula,
The first time that University of Oxford astronomer Lyla Jung saw the cosmic configuration on her monitor, she almost didn't believe it was real. But it wasand Jung and her colleagues went on to identify one of the largest rotating structures ever found in space: a chain of galaxies embedded in a spinning cosmic filament 400 million light-years from Earth. The finding, published in Monthly Notices of the Royal Astronomical Society, may give astronomers new insights into galaxies' formation, evolution and diversity, Jung says.
Out there, in the vast Universe, are clumps of matter that come in many different sizes and masses. We might be most familiar with galaxies like our Milky Way: with hundreds of billions of solar masses worth of stars, even more gas and plasma, and more than a trillion solar masses worth of dark matter. At smaller masses, however, it takes longer, and becomes more and more difficult, for clouds of normal matter to collapse.
Auroras are nature's most special light show: when charged particles from the sun hit our atmosphere, they can generate bright colors that dance across the night sky near the Earth's poles. Auroras can come in various forms, including bands, rays, patches and more. But why auroras form these patterns is less clear. Now, researchers say they've identified the battery that powers at least one kind of auroraaurora arcs.
On Tuesday night, the Aurora borealis may be visible in parts of more than half of all U.S. states. That's a few more than the usual six or so Northern states that are used to seeing the lit up skies. That's because solar storms can change visibility, making the spectacle visible to more locations in times of heightened geomagnetic activity.