Astronomy

For the first time, scientists have captured a zoomed-in photo of a star outside of our Milky Way galaxy. The image revealed surprising details about WOH G64, a giant star that is probably dying, researchers report November 21 in Astronomy & Astrophysics.

The star, which is about 1,500 times the size of our sun, sits 160,000 light-years away from Earth. It lives inside the Large Magellanic Cloud, a small galaxy that orbits the Milky Way. More

A colossal census of the cosmos has more than tripled the number of active black holes known to reside in miniature galaxies and found the biggest haul of middleweight black holes to date.

The survey turned up about 2,500 dwarf galaxies with actively feeding black holes at their centers, up from about 500 known before, researchers report in a paper submitted October 31 to arXiv.org. The team also found nearly 300 new intermediate-mass black hole candidates, an increase from about 70 previous possible detections (SN: 9/2/20). More

Some massive stars may go out with a fizzle, not a bang.

A star that winked out of view could be a “failed supernova,” a stellar explosion that petered out instead of fully detonating, a new study reports. If real, the failed supernova would mark the birth of a black hole.

At the ends of their lives, massive stars explode in dazzling outbursts known as supernovas, kicked off when the star’s core collapses. But sometimes, scientists suspect, there’s not enough oomph for a full explosion, resulting in a star that switches off without fireworks.  More

Some 6,500 light-years from Earth lurks a zombie star cloaked in long tendrils of hot sulfur.

Nobody knows how those tendrils formed. But astronomers now know where they’re going. New observations, reported in the Nov. 1 Astrophysical Journal Letters, capture the 3-D structure and motion of debris left in the wake of a supernova that was seen to detonate almost 900 years ago.

“It’s a piece of the puzzle towards understanding this very bizarre [supernova] remnant,” says astronomer Tim Cunningham of the Harvard & Smithsonian Center for Astrophysics in Cambridge, Mass. More

Dozens of fugitive stars were caught fleeing a dense star cluster in a satellite galaxy of the Milky Way. The swarm of speeding stars could mean that such runaways had a bigger influence on cosmic evolution than previously thought, astronomers report October 9 in Nature.

Massive stars are born in young clusters, packed so close together that they can jostle each other out of place. Sometimes, encounters between pairs of massive stars or neighboring supernova explosions can send a star zipping out of the cluster altogether, to seek its fortune in the wider galaxy and beyond. More

A red dwarf star known as Barnard’s star, which lies a mere six light-years from our solar system, has at least one — and possibly a handful — of small rocky planets orbiting it, a new study suggests.

Barnard’s star, which is about one-sixth the mass of our sun, is the closest individual star to our solar system. Only the three stars in the Alpha Centauri system are closer. Due to its proximity to Earth, Barnard’s star has long been a target of astronomers looking for exoplanets (SN: 12/1/73, SN: 12/7/23). More

Betelgeuse, Betelgeuse! The red supergiant that marks Orion’s left shoulder may have a tiny, unseen companion.

Two independent studies found evidence of a star about the same mass as the sun, orbiting Betelgeuse about once every 2,100 days.

“It was very surprising,” says astrophysicist Morgan MacLeod of the Harvard & Smithsonian Center for Astrophysics in Cambridge, Mass. If the star is real, “it’s kind of hidden right there in plain sight.”

MacLeod and colleagues linked a six-year cycle of Betelgeuse brightening and dimming to a companion star tweaking its orbit, in a paper submitted to arXiv.org September 17. MacLeod examined global, historical measurements dating back to 1896. More

While SpaceX’s Starlink satellites are enabling internet access and cell phone communications around the globe, they’re also posing a threat to radio astronomy, a new study suggests.

In some wavelength bands, unintended leakage of electromagnetic radiation from the latest generation of the satellites is more than 30 times brighter than emissions from previous versions, Cees Bassa, a radio astronomer at the Netherlands Institute for Radio Astronomy in Dwingeloo and his colleagues report September 18 in Astronomy & Astrophysics. Because the latest generation of Starlink satellites will orbit as many as 100 kilometers lower than earlier satellites, they’ll seem even brighter to ground-based telescopes. Overall, their brightness could easily mask observations of dimmer objects like distant galaxies or stars. More