News

Oldest Carbon-rich Stars Open a Window to Early Cosmic Chemistry

Astronomers studying the ultra-faint dwarf galaxy Pictor II have found an extremely chemically peculiar star that contains traces of elements created by the first stars in the Universe. It’s called PicII-503, a “second-generation star” that is one of the most chemically primitive stars ever found. It’s extremely low in iron but is enhanced with carbon. Its home galaxy, Pictor II, is a satellite of the Large Magellanic Cloud (itself a satellite of the Milky Way Galaxy), and lies some 150,000 light-years away. Its stars may play a role in helping us understand chemical evolution in early epochs of cosmic time.

Chemically enriched metal poor (CEMP) stars such as PicII-503 aren’t limited to just one area of space. Astronomers have found them in the Milky Way’s halo and have long worked to explain their existence. The fact that this star lives in a galactic “fossil graveyard” makes Pictor II good place to study other similar stars. What astronomers find there will contribute to an increased understanding of the chemical evolution of the earliest generations of stars. The galaxy’s few thousand stars are more than 10 billion years old and began forming relatively early in the history of the Universe. It stopped forming stars billions of years ago and this entire whole dwarf galaxy is dominated by dark matter,

*A chart showing the chemical composition of the first stars compared to the composition of the Sun. PicII-503 would show hydrogen and an enriched amount of carbon (among other elements). Courtesy NASA/ESA/STScI*

Understanding Ancient Stars

PicII-503 and stars like it act as stellar time capsules. That’s because they contain their original primordial hydrogen and helium (first created in the Big Bang), but they have really low amounts of heavy elements. To astronomers, “heavy” elements or “metals” are those cooked up inside stars (such as carbon, nitrogen, silicon, calcium and iron). The first stars in the Universe were mainly hydrogen and helium that did exactly that: fuse hydrogen to create helium, and then went on to fuse helium to carbon, carbon to nitrogen, and so on. The most massive stars fuse elements all the way to iron. When they try to make iron, they can’t support the process. Instead, they die, exploding as supernovae and spreading all those elements out to space through clouds of gas and dust.

The next generations of stars contain traces of whatever got cooked up in the cores of the first stars. That’s where PicII-503 came from, formed in a cloud of gas and dust seeded by elements from the long-dead first stars. During the stardeath process, heavy elements that form close to the supernova progenitor star’s interior, like iron, fall back into the remnant compact object. Lighter elements (such as carbon) lie closer to the outer regions of the star and they get blasted out to space to seed the interstellar medium. The ejected “star stuff” gets swept up in the formation of the next generation of stars.

This suggested link between second- and first-generation stars is what led astronomer Anirudh Chiti of Stanford University and an extensive team of researchers to the discovery of this PicII-503. “Discovering a star that unambiguously preserves the heavy metals from the first stars was at the edge of what we thought possible, given the extreme rarity of these objects,” said Chiti. “With the lowest iron abundance ever derived in any ultra-faint dwarf galaxy, PicII-503 provides a window into initial element production within a primordial system that is unprecedented.”

The Dark Energy Camera (DECam), on the Víctor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory (CTIO). It was used to survey the sky for CEMP stars to study. Credit: CTIO/NOIRLab/DOE/NSF/AURA/R. Hahn (Fermi National Accelerator Laboratory)

The team used the Dark Energy Camera on the Victor M. Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile as part of a survey called MAGIC (Mapping the Ancient Galaxy in CaHK). That survey operated for 54 nights, searching for the oldest and most chemically primitive stars in our galaxy as well as nearby ones. They also useddata from the Magellan/Baade Telescope and ESO’s Very Large Telescope to study the star. They found PicII-503 to be exceptionally metal-poor.

A Key to Understanding Early Element Production

So, did ancient supernovae play a role in the chemical mix in CEMP stars? The data from the survey and observations seem to support that idea. Astronomers think that some of the elements these objects do have came from low-energy supernova explosions of the first stars. Pictor II is a good place to look at this because of its dwarf status. If supernovae exploding within its “territory” had been very high-energy, then the metals they blew out to space would have escaped and not gotten swept up into Pictor’s second-generation stars. That likely explains the metal-poor character of PicII-503.

Chiti’s team and its work have provided a window onto the first chapters of chemical evolution in the Universe, if the findings as PicII-503 play out across other CEMP stars. “What excites me the most is that we have observed an outcome of the very initial element production in a primordial galaxy, which is a fundamental observation!” said Chiti. “It also cleanly connects to the signature that we have seen in the lowest-metallicity Milky Way halo stars, tying together their origins and the first-star-enriched nature of these objects.”

For More Information

Extremely Rare Second-generation Star Discovered Inside Ancient Relic Dwarf Galaxy

A Second-generation Star in a Relic Dwarf Galaxy

Enrichment by the First Stars in a Relic Dwarf Galaxy

News

ICE shootings protested in Pasadena on National Day of Action

urlhttps3A2F2Fcalifornia times brightspot.s3.amazonaws.com2F2d2F392F16f7756b428785707935b1a3

Approximately 50 demonstrators gathered Saturday morning in Pasadena as part of a national action to honor lives lost during immigration enforcement operations and in detention centers during the Trump administration.

They wore fliers around their necks, hung with yellow thread, bearing the smiling faces and names of some of the 75 people who have died since January 2025.

“Killed by ICE” was printed above a photo of each person, including local resident Roberto Carlos Montoya Valdez, a 52-year-old killed while trying to flee immigration agents who descended on a Home Depot in Monrovia last year.

The Los Angeles residents, part of the San Gabriel Foothills Indivisible group, carried American flags and held signs that read “No ICE No War” and “Stop ICE Murders.”

“Good morning, Pasadena,” Betsy Hanger, an organizer with the group, boomed into a megaphone as she walked through an intersection. “Honk for democracy. Honk if you want ICE off our streets now.”

A chorus of horns sounded as drivers signaled their support.

Organizer Andra Clarke held a banner in each hand that read “Neighbors Say ICE Out.” The sign around her neck carried the name and photo of Francisco Gaspar-Andrés, a 48-year-old who died in a Texas detention center in December.

Clarke, 61, said the group has been gathering at the intersection of Colorado Boulevard and Fair Oaks Avenue every Saturday since March. Last weekend, they celebrated civil rights activist John Lewis.

This Saturday, though, their focus was aimed at ICE.

“Now 75 people have died at the hands of ICE,” Clarke said. “We were originally told, ‘Oh they’re going to go after the criminals, the people who are the worst of the worst.’ That’s a lie; that is not what’s happening.

“They’re targeting communities, they’re targeting people of color. It’s fascism. … Anybody who cares about humanity should care about what’s happening.”

Clarke said it hit her hard when she learned of the two recent deaths at the hands of ICE.

The event was also a vigil honoring 52-year-old Lorenzo Salgado Araujo, who was killed by an ICE agent in Houston on July 7 while driving his construction crew to a job site, and Johan Sebastian Guerrero, 25, who was fatally shot by an ICE officer in Maine during a traffic stop earlier this month.

“It’s like, again? It just doesn’t end. It feels like it never ends — the evil.”

Shortly before noon, Clarke used a megaphone to read aloud the names of the dozens who have died. After each name read, Hanger struck a singing bowl, the vibrations sounding out in the corner where they stood. At times, she read “unidentified man” or “four unidentified women.”

Next to them was a poster board with a photo of Daphy Michel, a 31-year-old woman found unresponsive at a bus shelter in Pittsburgh after ICE released her “into cold winter conditions and no care for mental health episodes or notice to relatives.”

“Let’s take a moment of silence for all those who were taken,” Clarke said, bowing her head.

Among those gathered to listen was Leticia Lopez, a 65-year-old South Pasadena resident whose voice trembled as she talked about the impact of hearing about another arrest or death tied to enforcement operations.

“It gets me to the core,” she said, striking her chest. “It’s not getting any better, it’s getting worse. I just feel like I need to do something.”

Lopez, who wore a shirt that read “Immigrants are not criminals but the president is,” said her mother and grandmother were forcefully repatriated from Arizona to Mexico.

Her mother, who was raised in Mexico, later met her father there. He moved to the U.S. in the 1950s as a bracero. Hearing the stories of today, she said, “triggers everything that they went through.”

“When I see it happening, it’s a generational trauma that I feel,” she said. Lopez said people around her are carrying passports and documents in public to prove they’re citizens.

“Because they’re afraid they might be profiled, picked up, kidnapped by ICE. When my son goes out, I worry,” she said of her 28-year-old.

Later that afternoon, about four miles away outside of Home Depot in Pasadena, organizers staked in the ground dozens of white crosses that bore photos of the dead — the majority of them men. Attendees of the vigil laid flowers at the crosses in a makeshift cemetery.

“Shot dead by ICE,” read one with a photo of Keith Porter Jr., who was killed by an off duty ICE officer in California.

Several of them contained details of how the deaths unfolded. A man killed after a tractor trailer struck him as he fled an ICE raid in Florida. A Cuban immigrant who died in a detention center (his death was later ruled a homicide). A Mexican national who fell 30 feet to his death during a raid in California.

Among the photos on crosses were Renee Good and Alex Pretti.

“Are we going to wait until 70 more die to do something?” asked Marlom Portillo, an educator with the National Day Laborer Organizing Network, as he staked more crosses into the ground.

“What they want us to do is forget them,” Portillo added. “We will never get tired of denouncing this atrocity.”

“There are more people who died than there are people here protesting,” Kathleen Vallee, a Monrovia resident, observed to her friend. “And that says a lot about us.”

Vallee said when she attended the “No Kings” protest, it was “jam-packed.” Only a dozen people had gathered around 20 minutes into the vigil.

“It turns my stomach,” Vallee said, hands clasped. “This just seems to be seeping up from the sewer into our democracy and that motivates me.”

As the small crowd assembled, demonstrators carried signs that read “Every person is sacred,” “we keep us safe” and “neighbors say ICE out.” One woman carried a handmade sign that read: “Who will they come for next?”

Sheri Lochner, a 64-year-old Monrovia resident, is part of East Pasadena Community Defense Corner, a small group that “provides support and a sense of community” for day laborers.

Lochner said she watched as immigrant agents took six or seven men at an Oct. 1 ICE raid at the Monrovia Home Depot.

“So un-American,” Lochner said, as she scanned the rows of crosses. “This isn’t right.”

She added that her mom, who voted for Trump the first time, agreed with her.

“I speak up, I will not be silent,” she added.

News

Inside the Rushed Effort to Get Trump His New Air Force One

A New York Times investigation found that President Trump’s push to speed delivery of the aircraft led to ballooning costs and trade-offs in safety features.

News

Lucky 13! Starship Deploys Starlink Satellites and Splashes Down Intact

SpaceX’s Starship super-rocket deployed operational next-generation Starlink satellites for the first time during its 13th flight test, which addressed snags that arose in the previous test.

The 407-foot-tall, two-stage rocket rose from its Starbase launch pad in Texas at 5:51 p.m. CT today (10:51 p.m. UTC), with all 33 Raptor engines firing on the Super Heavy booster. On the way up, the rocket set a record for maximum dynamic pressure, also known as Max-Q.

Minutes after liftoff, the Starship upper stage — known as Ship — separated to continue on the flight test’s trajectory, and then the booster relit its engines for a controlled splashdown in the Gulf of Mexico. SpaceX launch commentator Dan Huot noted that not all of the engines fired up as planned — making for a splash that was a bit spicier than expected but still safe.

During the next phase of the test, Ship sent out 20 operational Starlink V3 satellites from a deployment system that’s been nicknamed the “Pez Dispenser.” For about 20 minutes, SpaceX’s engineering team ran a series of tests to check the deployment of solar arrays and see how the satellites were able to communicate with other spacecraft in the telecom network using laser systems.

“Not only were we able to make contact with all 20, but we also made comms over lasers with all of them as well,” SpaceX engineer Kate Tice said. “So, that is awesome.”

The satellites weren’t meant to stay in orbit. After the tests were completed, all 20 re-entered the atmosphere and burned up. But the data gathered during the tests will help SpaceX ensure that future batches of Starlink V3 satellites work properly.

Starlink V3 satellites are built to download data at speeds of up to 1 terabit per second, which marks a substantial technological advance over the V2 satellites that make up the bulk of the Starlink constellation. Adding V3 satellites to the network will upgrade Starlink’s capacity for direct-to-device services.

After satellite deployment, the upper stage executed a relight of one of its six Raptor engines in mid-flight, and then descended through the atmosphere to a splashdown in the Indian Ocean. On the way down, Ship’s heat shield weathered fiery flashes of plasma that made for quite a fireworks show on the in-space video transmitted down to Earth via Starlink. At the very end, the upper stage settled down intact in the water, spouting flames as it floated.

“That is a first. That is the softest splashdown we have ever had with a Starship there in the Indian Ocean,” Huot said. “This is a dream scenario for the team that’s trying to get this heatshield data.”

This marked the second test of SpaceX’s beefed-up Starship V3 rocket. The previous test in May followed a similar flight profile and was rated a success, but SpaceX made some modifications to systems on the Super Heavy booster as well as on the upper stage to address engine performance issues.

SpaceX’s initial attempt to launch the 13th flight test was aborted a week ago, at the moment of ignition, when four Raptor engines failed to start up for launch. After the scrub, SpaceX found six booster engines that raised concerns and replaced them for today’s second try.