Astronomy

Astronomers have found a giant interstellar cloud surprisingly close to Earth.

Lurking about 300 light-years from our solar system, this immense cloud of gas and dust is the closest of its kind ever found to Earth, beating the previous record holder by roughly 90 light-years. Despite being some 5,500 times as massive as the sun, the cloud went unnoticed — until now.

That’s because the cloud does not contain much carbon monoxide, the molecule astronomers often use to probe these clouds, called molecular clouds. Astronomers found this cloud by scanning the sky for ultraviolet light coming from a molecular cloud’s main constituent, hydrogen molecules. The results, published April 28 in Nature Astronomy, reveal a crescent-shaped cloud that, if visible, would appear to viewers on Earth as the largest single structure in the night sky — roughly 40 full moons wide. More

A potential dark galaxy — one made primarily of dark matter — may have been spotted in the local universe.

Dark galaxies are theoretical, starless systems whose discovery could help astronomers better understand galaxy formation. The new candidate was found within a large, fast-moving cloud of gas first seen in the 1960s. High-resolution observations of the cloud, reported April 18 in Science Advances, revealed a compact clump of gas that might be a dark galaxy. More

You may have already seen the headlines: Signs of life have reportedly been discovered on an alien world. 

A team of astronomers led by Nikku Madhusudhan of the University of Cambridge used the James Webb Space Telescope to search for interesting molecules in the atmosphere of a planet outside our solar system called K2 18b. The team now says they’ve found molecules that, on Earth, are associated with life, in an abundance that is hard to explain otherwise. More

For the first time, astronomers have confirmed the existence of a lone black hole — one with no star orbiting it.

It’s “the only one so far,” says Kailash Sahu, an astronomer at the Space Telescope Science Institute in Baltimore.

In 2022, Sahu and his colleagues discovered the dark object coursing through the constellation Sagittarius. A second team disputed the claim, saying the body might instead be a neutron star. New observations from the Hubble Space Telescope now confirm that the object’s mass is so large that it must be a black hole, Sahu’s team reports in the April 20 Astrophysical Journal. More

The decades-long mystery of a never-ending explosion of X-rays around the remains of a dead star may have finally been solved. The radiation probably originates from the scorching-hot wreckage left behind by a giant planet’s annihilation.

This discovery stems from four decades of X-ray observations of the Helix Nebula, located 650 light-years from Earth. The stream of X-ray radiation remained effectively constant over at least 20 years, researchers report in the January Monthly Notices of the Royal Astronomical Society. The best explanation, the scientists say, is that the ruins of a Jupiter-sized world continuously fall onto the nebula’s white dwarf star, getting frazzled and glowing in X-rays. More

The black hole at the Milky Way’s heart neither slumbers nor sleeps. Instead, the ring of plasma surrounding it flickers constantly, punctuated by superbright flares, observations show.

Astronomers used the James Webb Space Telescope to observe Sgr A* and its disk for hours at a time over the course of a year, from April 2023 through April 2024. These were the longest continuous observations yet of our galaxy’s central supermassive black hole.

The telescope revealed a “constant bubbling” in the disk’s light that changed every few seconds or minutes, says astrophysicist Farhad Yusef-Zadeh of Northwestern University in Evanston, Ill. A few times a day, and seemingly at random, the disk would emit a blindingly bright flare, Yusef-Zadeh and colleagues report in the Feb. 20 Astrophysical Journal Letters. More

In January in Monterrey, Mexico, Iván Venzor was one of only a dozen people in the world to glimpse a potential Jupiter-sized planet crossing in front of a distant star.

It happened too fast to see by eye — just a seconds-long flicker of light — but Venzor’s backyard telescope recorded the data, allowing him to verify the event with researchers. “I’m having dinner with my family, and I’m trying to discover a new kind of planet from a few meters outside,” says Venzor, a hobby astronomer. “It’s effortless.” More

The first generation of stars in the universe could have produced significant amounts of water upon their deaths, just 100 million to 200 million years after the Big Bang.

Signatures of water have previously been observed some 780 million years after the Big Bang. But now, computer simulations suggest that this essential condition for life existed far earlier than astronomers thought, researchers report March 3 in Nature Astronomy.

“The surprise was that the ingredients for life were all in place in dense cloud cores [leftover after stellar deaths] so early after the Big Bang,” says astrophysicist Daniel Whalen of the University of Portsmouth in England. More