Astronomers may have just found a first-of-its-kind phenomenon buried in the shadow of one of the Milky Way's most famous stellar explosions: two stars that died in separate supernovas, after spending millions of years orbiting each other.

Using 16 years of data from NASA's Fermi Gamma-ray Space Telescope, researchers detected high-energy gamma rays coming from a faint, previously overlooked supernova remnant called G189.6+3.3, which sits right beside the well-studied remnant IC 443 (nicknamed the Jellyfish Nebula). Their analysis suggests that the two remnants aren't just neighbors by coincidence. Instead, they may be the leftover wreckage of a binary star system, making this the first confirmed case of two supernova remnants traced to the same stellar pair.

The findings were published July 21 in the journal Nature Communications.

"We weren't really looking for a binary supernova remnant," study first author Miltiadis Michailidis, an astrophysicist and postdoctoral fellow at Stanford University, told Live Science. The team originally set out to characterize G189.6+3.3, which had long been overshadowed by its brighter neighbor. IC 443 is one of the best-studied remnants in the galaxy and among the first ever confirmed to accelerate protons — one of the key ingredients thought to produce cosmic rays, the high-energy particles that constantly strike Earth's atmosphere.

By combining Fermi's gamma-ray data with X-ray, radio, ultraviolet and optical observations, the team teased out G189.6+3.3's faint signal and found something strange: Instead of glowing uniformly, its northern half was dominated by accelerated protons, while its southern half was dominated by electrons. It's the first time such a clean split has been spotted within a single remnant.

The explanation, they found, came down to the environment: The northern edge of the remnant presses against a dense cloud of hydrogen gas, which gives fast-moving protons something to collide with, thereby producing gamma rays, Michailidis said. The southern half lacks that dense material, letting a different, electron-driven process take over instead. Ultraviolet observations showed that the northern shock wave had slowed after slamming into the cloud, backing up that interpretation.

Earlier work had already shown that IC 443 interacts with the same cloud, which implies that both remnants sit at roughly the same distance from Earth. To rule out coincidence, the researchers simulated 1 million hypothetical binary star systems and calculated how often two unrelated remnants would wind up this close together purely by chance. Depending on the method used, the odds came out to somewhere between 1 in 1,000 and 1 in 100. In other words, it's highly likely that the two supernova remnants are related.

The team also estimated when each star likely exploded, finding that the two blasts were probably separated by tens of thousands of years. That finding is consistent with one star in a binary pair going supernova first, with its companion following suit long afterward.

Rather than relying purely on computer models, astronomers can use this real-world system to test long-standing theories about how massive binary stars live, interact and eventually explode.

Michailidis said the team's next step is to search for similar binary remnant pairs elsewhere in the galaxy, to understand why this system has stood alone until now. He pointed to one particular payoff: Measuring the distance between two remnants' explosion centers can reveal how much energy a supernova actually released — a quantity that, until now, astronomers could only estimate from theory. "Now we can actually test it," he said.

Whale sharks may be the biggest fish in the ocean, but their feeding habits have remained mysterious. Now, new camera footage from the backs of these gentle giants has captured them doing something scientists rarely get to see: hunting for food far below the surface.

The footage reveals that whale sharks (Rhincodon typus) spend far more time feeding underwater than scientists realized and that they use a surprising variety of foraging techniques that had never been documented before.

The videos show whale sharks filtering food while cruising through open water, gliding downward as they feed during dives, climbing back toward the surface with their mouths still open, and cruising just above the seafloor to feed. Slow, steady underwater feeding turned out to be one of the sharks' most common activities.

Philip Motta, a professor emeritus of biology at the University of South Florida who was not involved in the study, said the videos provide "very valuable" new information on the variability of whale shark feeding behaviors, which have been poorly documented to date.

Cameras reveal whale shark feeding

Before this study, whale sharks had been studied from boats, from planes and by divers swimming alongside them. But those methods shared a blind spot: They could only follow the sharks when they were near the surface.

Earlier research had hinted that whale sharks spend a lot of time feeding out of view, at varying depths. In a 2020 study, researchers estimated that whale sharks may forage at these depths for up to 20% of the day and feed at the surface for less than 1% of their time.

In the new study, scientists strapped cameras directly onto the whale sharks, offering a rare shark's-eye view beneath the waves.

They deployed camera tags on 10 whale sharks at Ningaloo Reef in Western Australia and gathered more than 22 hours of footage from the sharks' own perspective. They combined that footage with a review of 106 previously published studies to build the most comprehensive catalog of whale shark behavior to date. Ultimately, they cataloged 36 distinct behaviors ‪—‬ 12 were related to feeding, and of those, six had never been recorded before. The findings were published July 21 in the journal Marine Biology.

Whale sharks can grow to 60 feet (18 meters) in length. And yet, this enormous fish survives on tiny prey ‪—‬ like krill, fish eggs and plankton ‪—‬ in tropical waters that are notoriously poor in nutrients. The ability to switch between so many feeding techniques may help to explain the long-standing puzzle of how such a large species can survive in these nutrient-poor waters.

However, even with a shark's-eye view, the cameras captured only part of the story. Whale sharks are known to dive hundreds of feet below the surface, where sunlight disappears and conventional cameras can no longer record.

"The most important new discoveries could be what these gentle giants are doing when they perform really deep dives," Motta said.

Shark quiz: How much do you know about these iconic ocean superstars?

Betelgeuse, the bright reddish star that marks Orion's shoulder, has kept skywatchers company for thousands of years — and it may have had company of its own the whole time.

Astronomers say they've captured the clearest image yet of a faint star orbiting tightly around Betelgeuse, in what they're calling the strongest evidence so far that the famous red supergiant isn't flying solo. The find was announced by the European Southern Observatory (ESO) on Tuesday (July 28) and detailed in a new paper in the journal Astronomy & Astrophysics.

Betelgeuse, usually one of the top 10 brightest stars visible from Earth, naturally swells and shrinks as it pulses across a cycle of 400 days, according to NASA, which causes the star to wax and wane in brightness. But for decades, scientists have puzzled over an extra pattern: a slower dimming and brightening outside of this 400-day cycle that repeats roughly every six years.

Two independent teams — one led by astrophysicist Morgan MacLeod of Harvard University, the other by Jared Goldberg, a postdoctoral fellow at the City University of New York — each modeled that long-term wobble using decades of brightness and velocity data, and converged on the same explanation: the pattern comes from a hidden companion star, orbiting so close to Betelgeuse's bloated surface that it's nearly impossible to see.

However, their calculations suggested that there might be a moment, in December 2024, when that companion would swing far enough away from Betelgeuse that we might be able to photograph it.

So that December, a team led by Paris Observatory astronomer Miguel Montargès trained the European Southern Observatory's Very Large Telescope on Betelgeuse. They then spent months combing through the data, and the effort paid off: they found what looks to be this companion star, now nicknamed Betelgeuse B.

"The fact that we can still discover a nearby companion, more massive and brighter than the Sun, around such a well-studied star is remarkable," Montargès said in an ESO statement. "These are among the best moments in science: seeing something new, unexpected."

One surprise: the companion turned out to be beefier than expected. Scientists had guessed it was roughly as massive as our sun, but the new images suggest it's actually two to three times heavier — which also makes it brighter and easier to spot than predicted.

However, the researchers say they need one more image of this star. To be certain that the companion is really there, we still need to observe it in one year on the other side of the star, but there is very little space left for doubt,"adds Montargès.

If confirmed, the discovery could reshape how astronomers think about Betelgeuse's fate. As a red supergiant, it's in the final stage of its life and will eventually end in a supernova explosion — though pinning down exactly when is notoriously difficult, says Montargès. "The question is … whether this companion is going to have an impact on the evolution of the red supergiant," Montargès said.