Study Findings: Discovery of a Star Sensitive to the Spin of Sagittarius A*

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Image (Credit): The Milky Way galaxy. (NASA)

Nature abstract of study findings:

Residing in the centre of the Milky Way, Sagittarius A* (Sgr A*) is the closest massive black hole1 (MBH). Its vicinity has allowed measuring individual stellar orbits around it. The stars act as test particles and probe the gravitational potential around the 4.3 × 106M⊙ MBH. These observations have determined the central mass to sub-per-cent precision, and the mildly relativistic motions of stars have given access to the dominant relativistic corrections, the gravitational redshift, the transverse Doppler effect and the prograde precession imposed by the Schwarzschild metric nature of the potential. These effects are of order β2 = (v/c)2 (for velocity v and speed of light c). The Kerr metric for a rotating black hole leads to corrections of order β3. Here, we report the discovery of a faint main-sequence star (mK = 19.3), S301, on an 8.7-year orbit and with small enough a pericentre distance, such that the peak velocity of the star reaches 25,000 km s−1. Within the measurement abilities of current near-infrared interferometry and future spectroscopy on an extremely large telescope, the motion of S301 is directly sensitive to the spin of Sgr A*. The high eccentricity of S301 suggests that it is the captured component of a binary that was torn apart by the Hills mechanism.

Citation:  Abd El Dayem, K., Abuter, R., Aimar, N. et al. Discovery of a star sensitive to the spin of Sagittarius A*. Nature 657, 359–363 (2026).

DOI: https://doi.org/10.1038/s41586-026-10894-w

Study-related stories:

Science News – “A Record-breaking Star Could Reveal How the Milky Way’s Giant Black Hole Spins”

Universe Today – “The Fastest Star in the Milky Way Will Test Relativity”

Sky & Telescope – “Star Feels Spin of Milky Way’s Black Hole”

Space Quote: Robots Plan to Visit the Moon

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Image (Credit): NASA’s Valkyrie humanoid robot. (NASA)

“Our team is not trying to replace human explorers with robots but instead make human exploration safer and more sustainable by developing highly capable, reliable, and trustworthy robots to work in extreme environments…If we can send more capable robots, we can reduce the risk and make people more effective in doing the things that people do best.”

-Statement by Shaun Azimi, NASA’s Dexterous Robotics Team lead. The 16-member Dexterous Robotics Team at NASA’s Johnson Space Center in Houston includes team member who had experience with earlier robot experiments, including Robonaut 2, used on the International Space Station, and Valkyrie, which is NASA’s first bipedal humanoid robot. Future robots are expected to assist with the Moon Base, lunar exploration, and eventually greater work on Mars (beyond the rovers and helicopter already on the Martian surface). This means that artificial intelligence (AI) will be heading to the moon as well while we still try to figure out what to do with AI back here on Earth. AI is already being used on the Martian surface with the Perseverance and Curiosity rovers.

Crew-13 Safely Arrives at the ISS

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Image (Credit): The SpaceX Dragon, with its nose cone open and carrying four Crew-13 members, approaches the International Space Station for a docking yesterday evening. (NASA)

A new ISS crew was launched from Cape Canaveral at 11:10 a.m. EDT Thursday, October 1, 2026 . Crew-13, consisting of NASA astronauts Jessica Watkins and Luke Delaney, Canadian Space Agency (CSA) astronaut Joshua Kutryk, and Roscosmos cosmonaut Sergey Teteryatnikov. The ride to the space station was scheduled to be about 8 hours. The SpaceX Dragon capsule carrying the crew safely docked with the ISS at 9:19 p.m. EDT.

The new crew will replace Crew‑12 consisting of NASA astronauts Jessica Meir and Jack Hathaway, European Space Agency astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev. These four crew members will be returning to Earth as soon as Monday, weather permitting.

Image (Credit): From left to right, Crew-13 NASA astronauts Jessica Watkins and Luke Delaney, CSA astronaut Joshua Kutryk, and Roscosmos cosmonaut Sergey Teteryatnikov. (NASA)

Pic of the Week: Colorful IC 348

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Image (Credit): IC 348 as captured by NASA’s JWST recently observed IC 348. (NASA, ESA, CSA, Kevin Luhman (PSU), Catarina Alves de Oliveira (ESA), Mahdi Zamani (ESA/Webb))

This week’s image is from the James Webb Space Telescope (JWST). With its sharp, amazing colors you would not think it is real, yet you are looking at a star-forming region about 1,000 light-years away called IC 348.

Here is NASA’s description of what you are seeing:

In regions like IC 348, cold clouds of molecular hydrogen gas collapse to form new stars, creating glowing, sculpted scenes like this one. The star-formation process can create widely varied objects, from massive stars that expire after only a few million years in core-collapse supernova explosions to the smallest and most common stars, which are long lived and produce powerful stellar storms.The smallest stars weigh in at around 8 percent of the Sun’s mass. Below this mass lies a strange class of objects called brown dwarfs. Brown dwarfs form in the same way stars do, through the collapse of molecular clouds. However, unlike stars, the cores of brown dwarfs never become hot enough to fuse ordinary hydrogen into helium (though many briefly fuse deuterium, or heavy hydrogen, early in their lives).

Sci-Fi Quote: Black Mirror is Today’s Twilight Zone

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Image (Credit): The crew from Black Mirror’s USS Callister. (Netflix)

“In Serling’s day, the atom bomb, civil rights, McCarthyism, psychiatry and the space race were of primary concern. Today he’d be writing about terrorism, the economy, the media, privacy and our relationship with technology…That’s what we’re aiming for with Black Mirror: each episode has a different cast, a different setting, even a different reality. But they’re all about the way we live now – and the way we might be living in 10 minutes’ time if we’re clumsy.”

-Statement by Charlie Brooker, creator of the Black Mirror series, as quoted by Collider. Season 8 of the series will premiere on Netflix shortly. The series has been very timely as we deal with new technologies, social media, and now artificial intelligence. You might also recall two earlier episodes with the USS Callister, which was a clever and dark mimicking of Star Trek. Another good episode, called “Beyond the Sea,” also dealt with space travel. Hopefully, we will get a least one more space-related episode out of the new season.