Astro Blog

By Steve Schulze et al, Nature.  Abstract: Stars are initially powered by the fusion of hydrogen to helium. These ashes serve as fuel in a series of stages 1 , 2 , 3 , transforming massive stars into a structure of shells. These are composed of natal hydrogen on the outside and consecutively heavier compositions inside, predicted to be dominated by He, C/O, O/Ne/Mg and O/Si/S (refs.  4 , 5 ). Silicon and sulfur are fused into iron, leading to the collapse of the core and either a supernova explosion or the formation of a black hole 6 , 7 , 8 , 9 . ...Here we report the discovery of the supernova (SN) 2021yfj resulting from a star stripped to its O/Si/S-rich layer. We directly observe a thick, massive Si/S-rich shell, expelled by the progenitor shortly before the supernova explosion.... [From ScienceAdvisor: Researchers spotted the consequential supernova, called SN 2021yfj, from California’s Zwicky Transient Facility, .... They found that the exploded star was about 60 times the ...

By Sarah Stanley , Eos/AGU.  Excerpt: Spectacular aurorae dance and shimmer nearly continuously at Jupiter’s poles. ...Sometimes, Jupiter’s aurorae grow much brighter for hours or days at a time. ... clarifying the solar wind’s role  in any one brightening event would require taking simultaneous measurements of Jupiter’s magnetosphere and aurorae and their relationship with the solar wind—a difficult undertaking. ...NASA’s  Juno mission  has made such simultaneous measurements possible.  Giles et al.  used data... from two of Juno’s onboard instruments...as Juno neared Jupiter in its elliptical orbit on 6 December, the spacecraft was overtaken by the outer edge of the shrinking magnetosphere before later reentering it closer to Jupiter. ...Another of Juno’s instruments, its ultraviolet spectrograph, measured the aurora’s peak power at this time to be 12 terawatts—6 times its baseline power level. ...the researchers concluded that the powerful auroral d...

By Daniel Clery , Science.  Excerpt: It’s as if the baby universe had caught a case of measles. Since NASA’s JWST observatory began peering into the distant universe in 2022, it has discovered a rash of “little red dots”—hundreds of them, shining within the first billion years of the 13.8-billion-year-old universe, so small and red that they defied conventional explanation. Only in the past few months has a picture begun to emerge. The little red dots, astronomers say, may be an entirely new type of object: a colossal ball of bright, hot gas, larger than the Solar System, powered not by nuclear fusion, but by a black hole. ...JWST couldn’t resolve the dots into a recognizable shape, which meant they must have been tiny—less than 2% of the diameter of the Milky Way....  Full article at https://www.science.org/content/article/early-universe-s-little-red-dots-may-be-black-hole-stars . 

By Heather Cox Richardson.  https://www.youtube.com/watch?v=Xh9-t8xqviM .

By McKenzie Prillaman , Science.  Excerpt: About 1,400 light-years from Earth sits a  young sunlike star surrounded by cooling gas and teensy silicate minerals . These mineral solids — some of the building blocks of rocky planets — are among the first to condense from the gas, suggesting that they’re kick-starting the creation of planets in a system much like the one earthlings call home, researchers report in the July 17  Nature . “It really is the first time we’ve seen this stage of planet formation in the process,” says planetary scientist Laura Schaefer of Stanford University, who was not involved in the new study. Observing the timeline of these early hot minerals will help researchers better understand how events unfolded billions of years ago in the solar system....  Full article at https://www.sciencenews.org/article/star-earliest-birth-planet-solar-system . 

By Katherine Kornei , The New York Times.  Excerpt: If our species manages to hang on for a few billion additional years, we might be in for a wild ride — stars passing in the vicinity of the sun could cause planets in our solar system to collide or even be ejected, according  to a paper published last month  in the journal Icarus. The findings even suggest a scenario in which our world ends not consumed by the sun, but in a carom prompted by the powers of gravity. ...The researchers found that the triple threat is a massive star that makes a close approach to the sun at a relatively low velocity, magnifying its gravitational effect. But the alignment of all these attributes is rare. “A huge fraction of stellar passages are inconsequential to our solar system,” Dr. Kaib said. The researchers found that 0.5 percent of their simulations resulted in planets colliding or a planet being ejected from the solar system....  Full article at https://www.nytimes.com/2025/06/28/...