A 2026 preprint proposes that neutrons produced near Sagittarius A* (Sgr A*), the Milky Way’s central black hole, could help power protons to petaelectronvolt (PeV) energies. In the model, some neutrons enter the black hole’s ergosphere and beta-decay; the resulting charged particles can then participate in a magnetic Penrose process that draws on the black hole’s rotation. The authors predict gamma rays and neutrinos from later interactions, but this is a theoretical scenario—not a confirmed observation that Sgr A* is operating as a PeVatron.
What the authors propose
Marina Cermeño and seven coauthors describe the scenario in “Sgr A* as a Galactic PeVatron: Multimessenger Signatures of the Magnetic Penrose Process”, submitted to arXiv on 3 September 2026. A PeVatron is a candidate source capable of accelerating particles to PeV energies; one PeV is 1015 electronvolts. The paper’s result is a modeled possibility, not a measurement of proton energies at the Galactic Center.
As an Amazon Associate I earn from qualifying purchases.
From accretion flow to ergosphere
The calculation starts with neutrons produced in the accretion flow around Sgr A*. The authors estimate their production spectrum from nuclear-reaction kinematics, then model neutron paths through the curved spacetime around a rotating, or Kerr, black hole. They assess which neutrons could reach the ergosphere—the region around a rotating black hole where rotational energy extraction can be possible—and undergo beta decay there.
Do these 3 things before closing this tab:
1Repair Windows errors before they cause bigger problems2Scan for outdated or missing drivers - takes under a minute3Clear out junk files and repair common Windows errorsWhy neutron decay matters
A neutron has no electric charge, so it does not respond directly to a magnetic field in the way a charged particle does. Beta decay turns a neutron into a proton and an electron, along with an antineutrino. In the proposed chain, the newly available charged particles can interact with the magnetic environment and take part in the magnetic Penrose process (MPP). The process is the modeled route for extracting rotational energy and accelerating escaping protons; it is not simply a claim that any neutron entering the region will become a PeV particle.
#1 Best Overall
- 3D Galaxy Crystal Ball: A detailed engraving of Milky Way Galaxy is masterfully etched inside ultra-clear K9 crystal, creating a mesmerizing cosmic display
- Crystal Ball Night Light - Includes an LED wooden base features a USB cable with on/off switch for powering via computer, adapter or portable charger. When powered, the crystal transforms into a soft night light, projects dreamy light rings onto ceilings
- Premium Craftsmanship - Made from optical-grade K9 crystal for diamond-like clarity and scratch resistance, enhancing the laser-engraved design and ensuring lifelong beauty
- Crystal Ball Decoration - Whether you're looking for a desk centerpiece, beside night light, or living room accent, this galaxy crystal ball can become an amazing landscape and enhance the ambiance of space
- Galaxy-Themed Crystal Ball Gifts: Arrives in an exclusive gift box, makes an ideal space-themed gifts for astronomy enthusiasts, space lovers & Collectors, or anyone seeking a touch of cosmic magic
How the proposed process could make a PeVatron
The MPP is a magnetized version of Penrose energy extraction, which draws on the rotation of a black hole. In this paper’s scenario, the relevant sequence is conditional at each step: neutrons must be produced, some must reach the ergosphere, decay products must interact in the magnetic environment, and some accelerated protons must escape. From the modeled neutron population and trajectories, the authors derive an escaping-proton spectrum reaching PeV energies.
This makes Sgr A* a candidate Galactic PeVatron within the model, rather than an established one. The paper’s computation estimates the proposed pathway; it does not report direct evidence that MPP has been observed at Sgr A* or that the predicted proton spectrum has been measured.
Rank #2
- Milky Way wall art décor – Create a large Milky Way Galaxy piece of art with this LEGO building kit for adults
- LEGO 3D-effect wall décor – A Milky Way Galaxy artwork created from 3,091 layered LEGO bricks and pieces to produce a 3D effect with depth and texture
- Packed with features – Wall art includes some of the Milky Way’s most famous stars, clusters and other spectacles, including Trappist-1, The Pleiades, The Crab Nebula and The Pillars of Creation
- Space gift idea – LEGO art set for adults who love astronomy and immersing themselves in creative activity
- A social building experience – This home décor gift idea is made with 5 different panels, each with its own building instructions booklet so a group of friends can create together
Predicted gamma rays and neutrinos
The authors trace the escaping protons to possible hadronic interactions in the Central Molecular Zone, the dense region around the Galactic Center. Those interactions could produce gamma rays and neutrinos. The paper predicts distinct gamma-ray spectral features that may contribute non-negligibly to very-high-energy emission already detected from the Galactic Center by H.E.S.S. and HAWC. A possible contribution is not a unique identification: the prediction does not establish that existing emission comes from MPP.
For neutrinos, the authors say the modeled flux remains below the diffuse Galactic component inferred by IceCube, while it may still contribute to high-energy emission from the Galactic Center. As they put it in the abstract, “The associated neutrino fluxes remain below the diffuse Galactic component inferred by IceCube, but may still contribute to the high-energy emission from the GC.”
Rank #3
- Astronomy Gifts: The galaxy ball is a thoughtful gift for astronomy lovers. You can gift it to your friends, teacher, boyfriend, husband, children, daughter, son, yourself on birthday, christmas, new year, father's day, mother's day, anniversary date. It will be a surprise for them who are astronomy Enthusiast
- Exquisite Crafts: Each ball is made by K9 crystal without bubbles, impurities or scratches. The 3D milky way galaxy is 3D engraved inside 8 cm ball by laser machine, will not fade or rub off
- Colorful Light Base: Each ball is equipped with a silver LED base. The light of the LED base can change color automatically or fixed color, and it will make the pattern clearer, especially in a dark environment, even you can use it as a night light. The light base has two models of power supply, one is using 3 AAA 1.5V batteries, another one is using the charging cable (the package doesn't include battery and plug), you can use the cable to connect the computer, car or portable charger
- Home Astronomy Decor: Crystal nightlight lamp creates a comfortable light, suitable decorations for Room, Nightstand, Courtyard, Dinner Table, Parties, Cafe, etc. It is not only a gift, but also an ornament, you can put it on bookshelf, desk, living room's table, bedside table, when you turn on the light, the galaxy is more clear and wonderful
- Ready To Be A Gift: This gift is packed in an elegant gift box. And there are a wish card and a wipecloth in package. Ready to send it out as a gift at any time as a surprise
What could test the prediction
The paper compares its modeled signals with projected instrument sensitivities. These comparisons describe potential observational reach, not present-day detections or guaranteed outcomes.
- SWGO: The authors report that their predicted signals fall within the project’s projected sensitivity across all scenarios they considered.
- CTAO: For some modeled cases, predictions are only a factor of a few below nominal projected sensitivity.
- KM3NeT/ARCA and IceCube-Gen2: The authors identify these as complementary tests of the neutrino predictions.
Agreement between a future measurement and one part of the forecast would be evidence to assess, not by itself proof of the entire neutron-to-MPP chain. Establishing the mechanism would require observations that support the predicted signals and distinguish them from other possible sources of Galactic Center emission.
Quick Recap
Best Value
- LAMINATED - Professionally double sided laminated (encapsulated) 24.25x36.25 inch (62x93 cm) poster. Laminated prints use specialty gloss lamination film for optimal durability and clarity. Posters are sealed on all sides with 4.5 mm edge thickness to protect against dirt, dust, moisture and humidity. Made in the USA.
- PREMIUM QUALITY POSTER Professionally printed artwork has vibrant colors and excellent clarity to ensure a beautiful finished product that looks great and are easy to hang on a wall or bulletin board, or even as a placemat.
- REUSABLE AND ERASABLE The clear optical plastic coating creates an ideal dry erase surface which makes hanging laminated artwork ideal ideal for any wipe off and on information in a kitchen, office, college dorm room or school classroom.
- HAND LAMINATED IN THE USA
- OFFICIALLY LICESNED NASA POSTERS NASA MUGS AND NASA CALENDARS - Add some Mars or outer space to your place with astronomy aesthetic wall decor. Perfect for a kids bedroom poster solar system space posters science art kids map wall galaxy classroom chart decor earth pictures outer planets planet hubble astronomy nasa milky way room educational universe print moon constellations model constellation glow sky shuttle deep field high world mars walls school cool retro picture star classrooms
Rank #4
- 【Captivating 3D Galaxy Design with LED Lighting】Experience the wonder of the Milky Way with this 3D galaxy crystal ball. Made with premium K9 crystal, the intricately designed Milky Way is brought to life by vibrant LED lighting, providing a stunning, colorful display that makes any space feel magical.
- 【The Perfect Astronomy Gift for All Ages】Delight space enthusiasts of all ages with a unique gift! This galaxy crystal ball is ideal for kids, teens, and adults who love astronomy, science, or stars. Whether it’s for a birthday, holiday, Christmas, or any special occasion, it’s a thoughtful present for educators, students, and collectors.
- 【Premium Design with Long-Lasting Quality】Crafted with exceptional quality, the galaxy is etched inside the crystal ball using advanced 3D laser engraving technology, ensuring a clear, sharp image that never fades. Combined with its durable LED base, this night light is built to last as a timeless piece of space decor.
- 【Multicolor LED Base for Dynamic Effects】With a touch-sensitive LED base, enjoy six vibrant color modes that add a dynamic glow to your room. Easily switch colors, turn the light on/off, or adjust the mode. Powered by AAA batteries or USB (5V input), it provides flexible options for bedroom, study, or workspace lighting.
- 【Stunning Space-Themed Home Decor】Transform your bedroom, living room, or office with this elegant galaxy night light. Perfect as a nightlight for kids or a desk accessory for space enthusiasts, it doubles as a captivating decor piece that combines functionality and beauty to enhance any space.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
