Outgoing longwave radiation

An ordinary flashlight shines in all directions, and after just a couple of dozen meters its beam fades so much it barely lights a wall. The atmosphere scatters light, and wind and heat currents distort it even more. But if you lay an invisible pipe for light right in the air, the beam will travel through it like water through a hose.

Ten billion years ago, the universe was speckled with strange crimson sparks. The JWST spotted them in images at distant redshifts — compact sources blazing like entire galaxies yet no larger than a tiny central region. Astronomers nicknamed them “little red dots.” Their nature long defied explanation.

A mosaic of large colored tiles. Each tile is the average precipitation over an entire month for an area the size of a small country. For a general understanding, the picture is fine, but if you need to know whether a downpour hit a specific city yesterday, it's useless.

Every galaxy is wrapped in an invisible shell of hot gas, like steam rising from a pot of boiling water. This gas barely glows in X-rays, making it notoriously difficult to measure. Yet it holds the memory of stellar explosions and the galaxy's growth. The new method uses light from a galaxy's bright center.

For eight consecutive years, two different methods of measuring the temperature of the solar corona have given different answers. One instrument, a radio telescope in Nancay, sees 600 thousand degrees. The other approach, calculating from how the gas is distributed with height, requires 1.5 million.

The solar corona, the Sun's outer atmosphere, stretches millions of kilometers, yet it's visible only during a total eclipse or with specialized instruments. Typically, we gauge the corona's density by how it scatters white light, but that method relies on simplifications that can skew the results.

A solar flare is like an explosion in a star's atmosphere: in minutes, it releases energy comparable to billions of nuclear bombs. On May 4, 2022, the RT-7.5 radio telescope in Moscow was watching an M5.7-class flare. The instrument was catching millimeter radio waves: those shorter than a centimeter and invisible to the eye.

At the heart of nearly every large galaxy lurks a supermassive black hole. As it devours gas, it blasts powerful outflows back into space, like a dragon that can't swallow all its prey and breathes fire. These 'winds' accelerate to thousands of kilometers per second and can sweep away the gas reservoirs from which stars are born.

The same explosion can sound different: it all depends on which way the wind is blowing. In 2024, researchers set off charges equivalent to ten tons of TNT twice and recorded the sound with a network of 31 microphones spread over a radius of 23 kilometers. The source was identical, but the acoustic pictures turned out to be quite different.

In the stream of charged particles that constantly blows from the Sun, radio bursts sometimes occur — short, powerful signals at frequencies you can pick up on an ordinary radio. Until now, it was unclear how exactly these signals are born in that stream.

An oven with three racks, each baking a different dish: that's the image that comes to mind when you look at the galaxy I Zw 18. The top rack is blazing at 21,200 kelvins, the middle one at 17,290, and the bottom at 16,170.

Any device, from a toaster to a smartphone, heats up when operating. This is the inevitable result of energy conversion — there's always a heat trace left, like a hot stove burner after cooking.

In 1976, Canadian physicist Bill Unruh asked a simple question: what does an observer see when accelerating through empty space? The answer turned out to be strange: emptiness ceases to be empty. An accelerating observer bathes in thermal radiation with a temperature proportional to the acceleration.