Saudi Arabia on Saturday said that Yemen's Houthi rebels tried to attack Riyadh with a ballistic missile, the first time the Saudi capital has been targeted since the escalation in fighting with the Iran-backed rebels opened a new front in the Iran war.

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Ed Sheeran opened a solo concert Saturday with comments about Gaza after controversy swirled around his tour and supporting acts withdrew in solidarity with opener Macklemore, who was dropped after making pro-Palestinian comments onstage.

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The U.N. expanded the United Nations Interim Force in Lebanon's mandate 20 years ago to include monitoring adherence to a ceasefire in fighting between Israel and Lebanon's Iran-backed Hezbollah — the militant group created in 1982 to counter a second Israeli invasion.

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Three reporters were blocked from the White House grounds Saturday morning, a day after President Trump said CNN, Politico, and MS NOW would be banned for reporting "FICTION and LIES."

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The Republic of Albania will sign the Artemis Accords during a ceremony at 12 p.m. EDT on Monday, Sept. 21, at NASA Headquarters in Washington, becoming the 73rd country signatory.

NASA Deputy Administrator Matt Anderson will host Albania’s Minister for Europe and Foreign Affairs Ferit Hoxha and Ambassador of the Republic of Albania to the United States Ervin Bushati for the ceremony, together with U.S. Department of State officials.

This event is in person only. Media interested in attending must RSVP no later than 10 a.m. on Sept. 21 to: hq-media@mail.nasa.gov. NASA’s media accreditation policy is online.

In 2020, during the first Trump Administration, the United States, led by NASA and the State Department, joined with seven other founding nations to establish the Artemis Accords, responding to the growing interest in lunar activities by both governments and private companies.

The Artemis Accords introduced the first set of practical principles aimed at enhancing the safety, transparency, and coordination of civil space exploration on the Moon, Mars, and beyond.

Learn more about the Artemis Accords at:

https://www.nasa.gov/artemis-accords

-end-

Camille Gallo / Elizabeth Shaw 
Headquarters, Washington 
202-358-1600 
camille.m.gallo@nasa.gov / elizabeth.a.shaw@nasa.gov 

Using data from the Japan-led XRISM (X-ray Imaging and Spectroscopy Mission) observatory, astronomers have directly observed a giant star’s outflow, called a stellar wind, being captured by its compact companion and providing the power source for strong X-ray flares. The research is part of NASA’s exploration of the extreme universe to better understand how the cosmos works.
 
“We’ve never before seen clear indications of wind plasma falling onto a compact object,” said Roi Rahin, a researcher at UMBC (University of Maryland, Baltimore County) and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “We can now test our understanding of these processes in much greater detail.”
 
A paper describing the findings published Friday in the journal Science Advances.
 
The target system is BP Crucis, a high-mass X-ray binary located about 13,000 light-years away in the southern constellation Crux. The primary star, known as Wray 977, is a blue hypergiant about 40 times the Sun’s mass and 60 times its size. It’s so big, hot, and luminous that ionized gas constantly streams away from it, a phenomenon astronomers call a stellar wind.

The supergiant’s companion is a tiny-but-mighty neutron star called GX 301-2. The crushed core of a star that long ago exploded as a supernova, it packs more than the Sun’s mass into a ball roughly 12 miles (20 kilometers) across. Rotating every 11 minutes, it sweeps an X-ray beam toward Earth, which classifies it as a pulsar.   
 
Twice during the pulsar’s 41.5-day orbit, near its closest and farthest points from the primary star, strong X-ray flares occur for several days. Astronomers think the pulsar’s gravitational influence on the star creates an especially dense stream of plasma. Flares occur when the pulsar traverses this stream and captures some of its matter. The strongest eruptions happen closer to the star, where the stream is denser. 
 
The researchers targeted the system with XRISM on Feb. 1, 2025, observing it for about 16 hours near the end of one of these stronger flares. The observatory’s Resolve instrument, jointly developed by NASA and JAXA (Japan Aerospace Exploration Agency), captured highly detailed X-ray spectra, revealing rapidly changing emission and absorption lines. In particular, absorption lines from highly ionized iron revealed the speed and direction of plasma relatively close to the pulsar. 

When Rahin first saw these spectra, he realized he hadn’t seen anything like them before. He scoured the scientific literature for similar observations and came up empty-handed.

“It was clear that these observations were groundbreaking, but at the same time this meant the analysis had to be especially detailed,” said Nazma Islam, a co-author formerly at UMBC and NASA Goddard and now an assistant professor at Manipal Centre for Natural Sciences, India. “We could see how the dense stream of plasma acts very close to the neutron star.”

Rahin and his team show that the iron absorption lines they observed are displaced to lower energies than they would be if measured in a laboratory. This displacement, called a redshift, indicates motion away from the observer, which means the gas is flowing toward the pulsar. The extent of the redshift indicates the plasma’s velocity. The team’s analysis indicates gas is racing toward the pulsar at speeds of around 335,000 mph (540,000 kph).
 
Here’s what the researchers think is going on: As the pulsar enters the stream, it sweeps up gas into a thick, messy, turbulent disk. This gas spirals down to the pulsar, heats up, and emits X-rays to power the flares.
 
As the pulsar pushes farther into the stream, the turbulent disk breaks down. Astronomers suspect that as the pulsar moves more directly into the flow, the stream no longer has the angular momentum required to maintain the disk. Once the disk dissipates, plasma flows directly onto the neutron star. Observations with XRISM occurred near the end of this phase.

Then, as the pulsar nears the end of the stream, a messy disk briefly returns, this time spinning in the opposite direction. And then it, too, disappears as the pulsar exits. In all, the pulsar takes about four days to transit the stream.

“The BP Crucis system is an ideal laboratory for studying wind-fed pulsar accretion, and XRISM’s sensitive, high-resolution Resolve spectrometer is an ideal instrument for advancing our understanding of the processes involved,” said Brian Williams, the mission’s project scientist at NASA Goddard.  

To learn more about the XRISM mission, visit:

https://nasa.gov/xrism