eccentric orbit

In a dense cloud of gas and dust where massive stars are born, two young stars recently passed very close to each other. Their dance has lasted only about sixty years, and astronomers have now seen it in detail for the first time.

The night sky looks serene, but it is actually pierced by an invisible rain of charged particles: cosmic rays. Scientists have long tried to figure out where the most energetic ones are born. Until recently, it was thought that our Galaxy supplies particles up to about 4 EeV, the so-called "ankle" in the spectrum.

Every 165 days, the giant planet dives toward its star, nearly grazing its fiery corona, then flies off into the icy void. This is TIC 241249530 b — an exoplanet with a record eccentricity of 0,94.

At the center of a galaxy, a huge black hole is shrouded in an invisible cloud — a swarm of ultralight particles that it itself spawned. Into this cloud dives another black hole, about the size of a star, and begins a long spiral dance. The approach takes millions of years, but the most dramatic events unfold right at the horizon.

The Kepler telescope spent years watching thousands of stars, spotting planets by the tiny dips in starlight when a planet passes in front of its star. Such a passage, or transit, lets us measure the planet's size but not the shape of its path.

A wormhole is a tunnel through space, connecting distant regions of the Universe. Its shadow against a bright gas background was long thought to be as round as that of a black hole. But for a rotating wormhole (one you could actually traverse), the shape of the shadow might be surprising: the edge becomes jagged, like a gear.

Interstellar wanderers are rocks and icy chunks that have broken free from their home planetary systems and now drift through the Galaxy. The first such visitor, 'Oumuamua, zipped past the Sun in 2017, followed by Comet Borisov and the ATLAS object. Where do they come from?

For 39 years, astronomers have been recording how the star BE Lyn brightens and dims. Its light pulsates with a rhythm of several hours, like a lighthouse that never stops blinking. But there is a glitch in this rhythm: sometimes the flashes came a little early, sometimes a little late. The star was moving closer to Earth and then farther away, as if something were dragging it in a circle.

The trace of a short-lived particle is like a signature left in the detector. The particle is born and decays in an instant, but from its trace you can reconstruct its character — whether it's compact like a stone or fluffy like a snowball. That's exactly what this work is about: the authors propose a new way to read such signatures. They noticed that each particle has an angle that links its mass and lifetime.