Fastest known Milky Way star offers new test of supermassive black hole's spin

Phys · Aug 19, 2026 · 876 words · By ESO

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What to know about Fastest known Milky Way star offers new test of supermassive black hole's spin

Astronomers using the European Southern Observatory's Very Large Telescope Interferometer have discovered S301, the fastest known star in the Milky Way. Due to its close orbit around the supermassive black hole Sagittarius A*, researchers believe the star can be used to directly measure the black hole's spin and test Einstein's general theory of relativity.

Propaganda risk 0%

Claims checked 16

Techniques found 0

Topics 0

Coverage spectrum

Coverage gap: Low Left coverage

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Center100%

Right0%

5 sources compared across this story cluster. This is an eFinder estimate from indexed source coverage, not an editorial rating.

What happened

Fastest known Milky Way star offers new test of supermassive black hole's spin Gaby Clark Scientific Editor Robert Egan Senior Editor Astronomers have discovered the fastest known star in our galaxy, the Milky Way, orbiting the black hole at its center.

Why it matters

The star, named S301, was detected with the European Southern Observatory's Very Large Telescope Interferometer (ESO's VLTI) and reaches speeds of 25,000 km/s (15,500 miles per second) as it travels around the four-million-solar-mass black hole.

Common ground

It comes closer to it than any other star observed before, so close that it feels the effects of the black hole's rotation.

Perspective signals

No major persuasion pattern has been attached yet, so the source, headline, and evidence should carry most of the weight for readers.

Follow-up questions

What concrete event or decision sits underneath the headline: Fastest known Milky Way star offers new test of supermassive black hole's spin?
What evidence would most clearly confirm or weaken the claim that S301... is the first known star that could be used to directly measure the rotation of a black hole?
What should readers watch for in the next update to know whether the story is changing?

open_in_new Read the original article: https://phys.org/news/2026-08-fastest-milky-star-supermassive-black.html

analyticsAnalysis

Propaganda Score

confidence: 100%

Low risk. This article shows minimal use of propaganda techniques.

fact_checkClaims Checked

eFinder analyzed this article and checked 16 claims against available evidence, cross-references, web search, and Wikipedia. Here is what the fact-checking layer found.

check_circle Corroborated 8

schedule Pending 6

verified Verified By Reference 1

help Insufficient Evidence 1

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Claim 1: “S301... is the first known star that could be used to directly measure the rotation of a black hole.”

CORROBORATED

Multiple sources state that because of its proximity, S301 is the first star that can be used to directly measure the rotation (spin/frame-dragging) of the black hole.

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web search NEUTRAL — S301 also comes closer to Sagittarius A* than any other star observed so far, approaching the black hole at around the distance of Saturn to the sun. Because S301 comes so close to Sagittarius A*, it …
https://www.soz6.com/news/fastest-known-milky-way-star-offer…

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web search NEUTRAL — A spinning black hole causes nearby orbiting stars to precess, meaning their orbital planes slowly rotate. Because S301 orbits so close to Sagittarius A*, this precession is strong enough to detect, g…
https://www.bushletter.com/astronomers-find-a-star-circling-…

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web search NEUTRAL — “S301 is the first star to orbit directly in the region around Sagittarius A* where the frame-dragging effect is extreme,” explained Felix Mang, PhD student at MPE and corresponding author of the stud…
https://thedebrief.org/newly-discovered-object-is-so-close-t…

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Claim 2: “taking just 8.7 years to complete it, and is approaching the black hole at a mere 12 times the distance of Earth to the sun.”

CORROBORATED

Web sources (BreezyScroll and others) confirm the orbital period of 8.7 years and a closest approach of just over 12 AU.

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web search NEUTRAL — S301 has an orbital period of approximately 8.7 years, making it one of the tightest-known stellar orbits around Sagittarius A*. Its orbit is also extremely eccentric. This matters because an elongate…
https://www.breezyscroll.com/space/s301-star-sagittarius-a-b…

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web search NEUTRAL — (AU is the symbol for astronomical unit, where 1 AU = 1.50 x 1011 m is the mean Earth–Sun distance.) How far from the Sun will Halley’s comet travel before it starts its return journey?Comet Halley ha…
https://www.transtutors.com/questions/comet-halley-figure-p1…

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web search NEUTRAL — The given information includes the perihelion distance of 0.6 AU and the orbital period of 76 years. Using these details, a number of further calculations involving celestial mechanics would typically…
https://www.bartleby.com/questions-and-answers/halleys-comet…

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Claim 3: “K. Abd El Dayem et al, Discovery of a star sensitive to the spin of Sgr A* Nature (2026). DOI: 10.1038/s41586-026-10894-w”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

schedule

Claim 4: “The VLTI's superpower lies in its ability to combine the light from four 8-meter (26-foot) telescopes to create a 'virtual' telescope with 15 times the spatial resolution of a single 8-meter (26-foot) telescope.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

verified

Claim 5: “Sagittarius A*”

VERIFIED BY REFERENCE

Wikipedia and multiple astronomical sources explicitly identify the central black hole of the Milky Way as Sagittarius A*.

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wikipedia NEUTRAL — Sagittarius A, abbreviated as Sgr A, is a complex radio source at the center of the Milky Way. Viewed from Earth, it is located near the border of the constellations Sagittarius and Scorpius, though i…
https://en.wikipedia.org/wiki/Sagittarius_A

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wikipedia NEUTRAL — Sagittarius A*, abbreviated as Sgr A* ( SADGE-AY-star), is the supermassive black hole at the Galactic Center of the Milky Way. Viewed from Earth, it is located near the border of the constellations S…
https://en.wikipedia.org/wiki/Sagittarius_A*

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wikipedia NEUTRAL — The Sagittarius Dwarf Spheroidal Galaxy (Sgr dSph), also known as the Sagittarius Dwarf Elliptical Galaxy (Sgr dE or Sag DEG), is an elliptical loop-shaped satellite galaxy of the Milky Way. It contai…
https://en.wikipedia.org/wiki/Sagittarius_Dwarf_Spheroidal_G…

+ 3 more evidence sources

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Claim 6: “It comes closer to it than any other star observed before”

CORROBORATED

Web sources and reports from the research team state that S301 has the shortest recorded orbital period and the tightest/closest observed approach to the galactic center.

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wikipedia NEUTRAL — S301 is a faint main-sequence star orbiting Sagittarius A* (Sgr A*), the supermassive black hole at the centre of the Milky Way. Its discovery was reported by the GRAVITY collaboration in August 2026.…
https://en.wikipedia.org/wiki/S301

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wikipedia NEUTRAL — S55 (also known as S0–102) is a star that is located very close to the centre of the Milky Way, near the radio source Sagittarius A*, orbiting it with an orbital period of 12.8 years. This beat the re…
https://en.wikipedia.org/wiki/S55_(star)

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wikipedia NEUTRAL — The Sagittarius A* cluster is the cluster of stars in close orbit around Sagittarius A*, the supermassive black hole at the center of the Milky Way (in the Galactic Center). The individual stars are o…
https://en.wikipedia.org/wiki/Sagittarius_A*_cluster

+ 3 more evidence sources

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Claim 7: “its next closest passage in 2031.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 8: “They could also trace S301's orbital history back to 2017, finding that it last made its closest approach to the central black hole in early 2023.”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 9: “The star, named S301, was detected with the European Southern Observatory's Very Large Telescope Interferometer (ESO's VLTI)”

CORROBORATED

The ESO website and other web sources explicitly state that star S301 was detected using the European Southern Observatory's Very Large Telescope Interferometer (VLTI).

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wikipedia NEUTRAL — 'Dante' Minniti (born December 1, 1962) is an Argentinian astronomer. He has devoted his career to the study of stellar populations, stellar evolution, globular clusters, galaxy formation, gravitation…
https://en.wikipedia.org/wiki/Dante_Minniti

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web search NEUTRAL — The Very Large Telescope (VLT) is an astronomical facility operated since 1998 by the European Southern Observatory, located on Cerro Paranal in the Atacama Desert of northern Chile.
https://en.wikipedia.org/wiki/Very_Large_Telescope

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web search NEUTRAL — The star, named S301, was detected with the European Southern Observatory’s Very Large Telescope Interferometer (ESO’s VLTI) and reaches speeds of 25 000 km/s as it travels around the four-million-Sol…
https://www.eso.org/public/news/eso2612/

+ 1 more evidence source

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Claim 10: “reaches speeds of 25,000 km/s (15,500 miles per second) as it travels around the four-million-solar-mass black hole.”

CORROBORATED

Multiple sources (ESO, Wikipedia, and web reports) confirm the star S301 reaches speeds of 25,000 km/s and orbits a black hole with a mass of four million solar masses.

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+ 3 more evidence sources

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Claim 11: “Finding S301, which appears 2 billion times fainter than Betelgeuse”

INSUFFICIENT EVIDENCE

No evidence was found in the provided search results regarding the specific brightness comparison between S301 and Betelgeuse.

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Claim 12: “the team managed to catch a first glimpse of the new star in spring 2023”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

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Claim 13: “approaching the black hole at around the distance of Saturn to the sun.”

CORROBORATED

Multiple sources describe the closest approach distance (12 AU) as being approximately the distance from the Sun to Saturn.

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web search NEUTRAL — The research team said this close approach makes it the star with the shortest recorded orbital period and the tightest ever observed in the galaxy’s center.One of the cooler stars, S301, is approachi…
https://thedebrief.org/newly-discovered-object-is-so-close-t…

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web search NEUTRAL — S301 is a newly identified star orbiting Sagittarius A*, the Milky Way’s central supermassive black hole. It reaches about 25,000 km/s, or roughly 8%–8.5% of the speed of light. Its closest approach i…
https://www.breezyscroll.com/space/s301-star-sagittarius-a-b…

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web search NEUTRAL — The star, named S301, is travelling at about 25,000KM/second when it makes its closest approach to the black hole known as Sagittarius A* (pronounced Sagittarius A-star). That is more than 8% of the s…
https://www.etvbharat.com/en/technology/found-milky-ways-fas…

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Claim 14: “Astronomers have discovered the fastest known star in our galaxy, the Milky Way, orbiting the black hole at its center.”

CORROBORATED

Multiple independent sources, including AP and other web reports, confirm the discovery of the fastest known star in the Milky Way orbiting the central supermassive black hole.

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wikipedia NEUTRAL — The Milky Way or Milky Way Galaxy, or simply the Galaxy, is the galaxy that includes the Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the nig…
https://en.wikipedia.org/wiki/Milky_Way

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wikipedia NEUTRAL — Milky Way is an American brand of malt-flavored milk chocolate-covered confectionery snacks manufactured and marketed by Mars Inc. since 1923. Created by Frank Mars, it was his first chocolate bar pro…
https://en.wikipedia.org/wiki/Milky_Way_(chocolate_bar)

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+ 4 more evidence sources

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Claim 15: “The team used the VLTI, a facility at ESO's Paranal Observatory in Chile, and its GRAVITY instrument, now known as GRAVITY+ following an infrastructure upgrade.”

CORROBORATED

While the specific 'GRAVITY+' upgrade name wasn't in every result, multiple sources confirm the use of the VLTI at Paranal Observatory and the GRAVITY instrument, with The Debrief explicitly mentioning the GRAVITY+ project.

schedule

Claim 16: “the star was likely part of a binary pair that was torn apart by the tidal forces of Sagittarius A*”

PENDING

This claim was extracted as a checkable statement from the article. eFinder labels it pending based on the available evidence and source context shown below.

info Disclaimer: This analysis is generated by AI and should be used as a starting point for critical thinking, not as definitive truth. Claims are verified against publicly available sources. Always consult the original article and additional sources for complete context.