Hydrogen sulfide detected in distant gas giant exoplanets for the first time

This animation shows the four giant planets orbiting HR 8799, located 133 light-years from Earth. The movie combines real images captured at the W.M. Keck Observatory between 2009 and 2021, with the planets’ orbital motion smoothed by modeling their orbital paths around the star.
Image Credit: W. Thompson (NRC-HAA), C. Marois (NRC-HAA), Q. Konopacky (UCSD) 

Scientific Frontline: "At a Glance" Summary

• Main Discovery: Astronomers detected hydrogen sulfide molecules for the first time in the atmospheres of four massive gas giant exoplanets orbiting the star HR 8799.
• Methodology: Researchers utilized spectral data from the James Webb Space Telescope (JWST), applying new data analysis algorithms to suppress starlight and creating specialized atmospheric models to identify the unique light absorption signatures of sulfur.
• Key Data: The target system is located 133 light-years away in the constellation Pegasus, with the observed planets ranging from 5 to 10 times the mass of Jupiter and orbiting at distances greater than 15 astronomical units from their host star.
• Significance: The presence of sulfur indicates these bodies formed by accreting solid particles from a protoplanetary disk rather than collapsing directly from gas, definitively classifying them as planets rather than brown dwarfs.
• Future Application: The signal processing techniques developed for this study establish a viable method for characterizing the atmospheres of smaller, rocky worlds and searching for biosignatures on Earth-like exoplanets in the future.
• Branch of Science: Astronomy, Astrophysics and Planetary Science.
• Additional Detail: The study reveals that these distant giants share a heavy element enrichment pattern similar to Jupiter and Saturn, suggesting a universal formation mechanism for gas giants across different stellar systems.

What Is: Cosmic Event Horizon

The Final Boundary
An illustration of the Cosmic Event Horizon. Unlike the Observable Universe, which is defined by light that has reached us, this horizon marks the limit of causal contact. Beyond this line, space expands faster than the speed of light, meaning no signal sent from Earth today could ever overtake the expansion to reach galaxies in these regions.
Image Credit: Scientific Frontline

Scientific Frontline: Extended "At a Glance" Summary

• The Core Concept: A theoretical boundary in the universe separating events that can ever causally affect an observer from those that never will; effectively, it marks the absolute limit of future visibility.
• Key Distinction/Mechanism: Unlike the Particle Horizon (which defines the observable past) or the Hubble Sphere (a kinematic boundary where recession velocity equals the speed of light), the Event Horizon is a strict causal limit determined by the accelerating expansion of space. Light emitted from galaxies beyond this horizon at the present moment will never reach Earth, regardless of how much time passes.
• Origin/History: Rooted in the standard \(\Lambda\)CDM model of cosmology; current interest is driven by the "Crisis in Cosmology" regarding Dark Energy and the Cosmological Coupling hypothesis, which suggests a link between black hole growth and cosmic expansion.
• Major Frameworks/Components:
• \(\Lambda\)CDM Model: The standard framework involving Dark Energy and Cold Dark Matter that predicts the horizon's existence.
• FLRW Metric: The geometry of spacetime describing an expanding universe.
• Cosmological Coupling: A recent hypothesis positing that black holes are the source of Dark Energy.
• Black Hole Cosmology: A theoretical model suggesting our observable universe may be the interior of a black hole within a larger parent universe.
• Branch of Science: Cosmology, Astrophysics, Theoretical Physics.
• Future Application: Critical for refining models of Dark Energy and testing the limits of General Relativity; ultimately essential for predicting the long-term fate of the universe (e.g., "Cosmic Solitude").
• Why It Matters: It defines the fundamental limits of our reality and causal connection to the rest of the cosmos. Recent theories connecting this horizon to black hole physics could radically alter our understanding of the Big Bang, suggesting our universe is a "cell" within a larger multiverse rather than an isolated expanse.

UrFU Researchers Discovered “Laughing Gas” in Interstellar Ices around Protostars

Anton Vasyunin leads the research group and laboratory.
Photo Credit: UrFU press service

Scientific Frontline: Extended "At a Glance" Summary

The Core Concept: Researchers have definitively identified nitrous oxide (N₂O), commonly known as "laughing gas," within the solid ice mantles coating dust particles around young protostars.

Key Distinction/Mechanism: Unlike the gas phase of the interstellar medium—where over 300 molecules have been identified—molecules in the solid "ice" phase are notoriously difficult to detect and are only visible via infrared absorption spectra. N₂O is only the ninth molecule ever confirmed in this frozen state.

Origin/History:

• January 2026: Findings were reported by the Ural Federal University (UrFU) and published in the journal Astronomy and Astrophysics.
• Methodology: The discovery relied on observational data from the James Webb Space Telescope (JWST), which was interpreted using laboratory-generated spectra of ice analogues created at UrFU's ISEAge laboratory.

Major Frameworks/Components:

• Infrared Spectroscopy: The primary method used to detect molecular signatures in solid ices, requiring background starlight to "illuminate" the absorption features.
• Protostars: The study analyzed 50 young stars, finding N₂O in 16 of them.
• Orion Molecular Cloud: A specific region where half of the positive detections were located, suggesting that high-intensity ultraviolet radiation aids in N₂O formation.

Branch of Science: Astrochemistry, Astrophysics.

Future Application: These findings improve models of chemical evolution in the universe, helping scientists understand how complex volatiles form and survive in the raw materials that eventually coalesce into planetary systems.

Why It Matters: This discovery indicates that nitrous oxide is relatively abundant in star-forming regions (found in nearly a third of surveyed targets), adding a critical piece to the puzzle of how prebiotic chemistry develops in the freezing vacuum of space before planets are born.

International astronomical survey captures remarkable images of the “teenage years” of new worlds

This ARKS gallery of faint debris disks reveals details about their shape: belts with multiple rings, wide smooth halos, sharp edges, and unexpected arcs and clumps, which hint at the presence of planets shaping these disks; and chemical make-up: the amber colors highlight the location and abundance of the dust in the 24 disks surveyed, while the blue their carbon monoxide gas location and abundance in the six gas-rich disks.
Image Credit: Sebastian Marino, Sorcha Mac Manamon, and the ARKS collaboration

Scientific Frontline: Extended "At a Glance" Summary

The Core Concept: The ARKS (ALMA survey to Resolve exoKuiper belt Substructures) program is an international astronomical survey that has captured the first high-resolution images of debris disks, which represent the chaotic "teenage" phase of planetary system evolution.

Key Distinction/Mechanism: Unlike the bright, gas-rich disks of newborn planets ("baby pictures"), these "teenage" systems are fainter dusty belts that exist after planets have formed but before the system settles into adulthood; the survey utilizes the Atacama Large Millimeter/submillimeter Array (ALMA) to resolve minute details like dust grains and carbon monoxide gas, revealing complex substructures rather than simple, uniform rings.

Origin/History: The survey team, led by the University of Exeter, secured approximately 300 hours of observation time at the ALMA observatory between October 2022 and July 2024, with findings published in a series of papers in Astronomy & Astrophysics.

Cosmic Lens Reveals Hyperactive Cradle of Future Galaxy Cluster

The galaxy cluster lens J0846 in optical light (bottom right), the ALMA view of dust-enshrouded, star-forming galaxies strongly lensed into bright arcs (top right), and a composite view (left) revealing at least 11 dusty galaxies in a compact protocluster core more than 11 billion light-years away, magnified by the foreground cluster’s gravity.
Image Credit: NSF/AUI/NSF NRAO/B. Saxton; NSF/NOIRLab

Galaxy clusters are formed by a dense packing of many galaxies, making them the most massive structures in the Universe. Their progenitors, protoclusters, show these galaxies in their infancy, offering a window to study how they all formed. This early “settlement” of galaxies will eventually evolve into a sprawling metropolis by the present day. Astronomers using the U.S. National Science Foundation Very Large Array (NSF VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a rare protocluster that was exceptionally bright, all when the Universe was 11 billion years younger. The system, called PJ0846+15 (J0846), is the first strongly lensed protocluster core discovered, revealing how some of the most massive galaxy clusters in the present-day Universe began their lives.

Young Galaxies Grow Up Fast

The 18 galaxies from the ALPINE-CRISTAL-JWST survey. Each picture shows the location of ionized gas (as traced by the hydrogen alpha line, the spectral signature of hot hydrogen gas) in the galaxies. Several of the pictured galaxies are interacting, meaning two or even three galaxies are in the process of merging.
Image Credit: Andreas Faisst (Caltech) and the ALPINE-CRISTAL-JWST Survey team

Astronomers have captured the most detailed look yet at faraway galaxies at the peak of their youth, an active time when the adolescent galaxies were fervently producing new stars. The observations focused on 18 galaxies located 12.5 billion light-years away. They were imaged across a range of wavelengths from ultraviolet to radio over the past eight years by a trio of telescopes: NASA's Hubble Space Telescope; NASA's James Webb Space Telescope (JWST); and ALMA (Atacama Large Millimeter/submillimeter Array) in Chile, of which the U.S. National Science Foundation National Radio Astronomy Observatory is a partner. Data from other ground-based telescopes were also used to make measurements, such as the total mass of stars in the galaxies.

"With this sample, we are uniquely poised to study galaxy evolution during a key epoch in the universe that has been hard to image until now," says Andreas Faisst, a staff scientist at IPAC, a science and data center for astronomy at Caltech. "Thanks to these exceptional telescopes, we have spatially resolved these galaxies and can observe the stages of star formation as they were happening and their chemical properties when our universe was less than a billion years old."

Earliest, hottest galaxy cluster gas on record could change our cosmological models

Artist’s impression of a forming galaxy cluster in the early universe: radio jets from active galaxies are embedded in a hot intracluster atmosphere (red), illustrating a large thermal reservoir of gas in the nascent cluster.
Image Credit: Lingxiao Yuan

The scorching cloud of gas threaded between clusters of galaxies is five times hotter than current models predict, highlighting gaps in our models of galaxy cluster formation.

An international team of astronomers led by Canadian researchers has found something the universe wasn’t supposed to have: a galaxy cluster blazing with hot gas just 1.4 billion years after the Big Bang, far earlier and hotter than theory predicts.  

The result, published in Nature, could upend current models of galaxy cluster formation, which predict such temperatures will occur only in more mature, stable galaxy clusters later in the universe’s life.  

“We didn’t expect to see such a hot cluster atmosphere so early in cosmic history,” said lead author Dazhi Zhou, a PhD candidate in the UBC department of physics and astronomy. “In fact, at first, I was skeptical about the signal as it was too strong to be real. But after months of verification, we’ve confirmed this gas is at least five times hotter than predicted, and even hotter and more energetic than what we find in many present-day clusters.”  

A speed camera for the universe

The stars (or rather galaxies) of the show.
A montage of eight time-delay gravitational lens systems. There’s an entire galaxy at the center of each image, and the bright points in rings around them are gravitationally lensed images of quasars behind the galaxy. These images are false-color and are composites of data from different telescopes and instruments.
Image Credit: ©2025 TDCOSMO Collaboration et al.
(CC BY-ND 4.0)

There is an important and unresolved tension in cosmology regarding the rate at which the universe is expanding, and resolving this could reveal new physics. Astronomers constantly seek new ways to measure this expansion in case there may be unknown errors in data from conventional markers such as supernovae. Recently, researchers including those from the University of Tokyo measured the expansion of the universe using novel techniques and new data from the latest telescopes. Their method exploits the way light from extremely distant objects takes multiple pathways to get to us. Differences in these pathways help improve models on what happens at the largest cosmological scales, including expansion.

Helium leak on the exoplanet WASP-107b

Artist's view of WASP-107b. The planet’s low density and the intense irradiation from its star allow helium to escape the planet and form an asymmetric extended and diffuse envelope around it.
Image Credit: © University of Geneva/NCCR PlanetS/Thibaut Roger

An international team including UNIGE observed with the JWST huge clouds of helium escaping from the exoplanet Wasp-107b. 

An international team, including astronomers from the University of Geneva (UNIGE) and the National Centre of Competence in Research PlanetS, has observed giant clouds of helium escaping from the exoplanet WASP-107b. Obtained with the James Webb Space Telescope, these observations were modeled using tools developed at UNIGE. Their analysis, published in the journal Nature Astronomy, provides valuable clues for understanding this atmospheric escape phenomenon, which influences the evolution of exoplanets and shapes some of their characteristics. 

Sometimes a planet’s atmosphere escapes into space. This is the case for Earth, which irreversibly loses a little over 3 kg of matter (mainly hydrogen) every second. This process, called ‘‘atmospheric escape’’, is of particular interest to astronomers for the study of exoplanets located very close to their star, which, heated to extreme temperatures, are precisely subject to this phenomenon. It plays a major role in their evolution. 

Stars defy the black hole: research in Cologne shows stable orbits around Sagittarius A*

Image Credit: NASA

New observations made with the ERIS instrument at the Very Large Telescope facility disprove from the assumption that the supermassive black hole at the center of the Milky Way devours nearby dust objects. 

An international research team led by PD Dr Florian Peißker at the University of Cologne has used the new observation instrument ERIS (Enhanced Resolution Imager and Spectrograph) at the Very Large Telescope (VLT) facility in Chile to show that several so-called ‘dusty objects’ follow stable orbits around the supermassive black hole Sagittarius A* at the center of our galaxy. Earlier studies had surmised that some of these objects could be swallowed up by the black hole. New data refutes this assumption. The findings have been published under the title ‘ABCD’ in the journal Astronomy & Astrophysics. 

The study focused on four of these unusual celestial bodies, which have been the subject of much discussion in recent years. In particular, G2 was long regarded as a pure dust and gas cloud. It was thought to have been initially elongated by the gravitational pull of Sagittarius A*, a process known as 'spaghettification', before being destroyed. However, the specific observations made with ERIS, which captures radiation in the near-infrared range, show that G2 follows a stable orbit. This is an indication that there is a star inside the dust cloud. These results confirm that the center of the Milky Way is not only destructive but can also be surprisingly stable. 

A sparkling ‘Diamond Ring’ in space: Astronomers in Cologne unravel the mystery of a cosmic ring

Stars Brewing in Cygnus X
Image Credit: NASA/JPL-Caltech/Harvard-Smithsonian CfA

The structure of gas and dust resembles a glowing diamond ring. Computer simulations and observations made on board the 'flying observatory' SOFIA are now able to explain the special shape. 

An international team led by researchers from the University of Cologne has solved the mystery of an extraordinary phenomenon known as the ‘Diamond Ring’ in the star-forming region Cygnus X, a huge, ring-shaped structure made of gas and dust that resembles a glowing diamond ring. In similar structures, the formations are not flat but spherical in shape. How this special shape came about was previously unknown. The results have been published under the title ‘The Diamond Ring in Cygnus X: an advanced stage of an expanding bubble of ionized carbon’ in the journal Astronomy & Astrophysics. 

The ring has a diameter of around 20 light years and shines strongly infrared light. It is the relic of a former cosmic bubble that was once formed by the radiation and winds of a massive star. In contrast to other similar objects, the ‘Diamond Ring’ does not have a rapidly expanding spherical shell, but only a slowly expanding ring. 

Astronomers discover a superheated star factory in the early universe

Glowing deep red from the distant past: galaxy Y1 shines thanks to dust grains heated by newly-formed stars (circled in this image from the James Webb telescope).
Image Credit: NASA, ESA, CSA, STScI, J. Diego (Instituto de Física de Cantabria, Spain), J. D’Silva (U. Western Australia), A. Koekemoer (STScI), J. Summers & R. Windhorst (ASU), and H. Yan (U. Missouri)

Astronomers have uncovered a previously unknown, extreme kind of star factory by taking the temperature of a distant galaxy using the ALMA telescope. The galaxy is glowing intensely in superheated cosmic dust while forming stars 180 times faster than our own Milky Way. The discovery indicates how galaxies could have grown quickly when the universe was very young, solving a long-standing puzzle for astronomers.  

The first generations of stars formed under conditions very different from anywhere we can see in the nearby universe today. Astronomers are studying these differences using powerful telescopes that can detect galaxies so far away their light has travelled towards us for billions of years.   

Astronomy: In-Depth Description

James Webb Space Telescope view of IRAS 04302+2247, a planet-forming disc located about 525 light-years away in a dark cloud within the Taurus star-forming region.
Image Credit: ESA/Webb, NASA & CSA, M. Villenave et al.

Astronomy is the natural science dedicated to the study of all celestial objects and phenomena originating beyond Earth's atmosphere. Its primary goals are to understand the physical and chemical properties of these objects, their origins and evolution, and the fundamental laws governing the universe as a whole.

McGill-led team maps ‘weather’ on a nearby brown dwarf in unprecedented detail

Study reveals patchy clouds and shifting atmospheric layers on a free-floating planetary-mass object just 20 light-years away, offering potential insights into planet and star formation
Image Credit: Anastasiia Nahurna.

Researchers at McGill University and collaborating institutions have mapped the atmospheric features of a planetary-mass brown dwarf, a type of space object that is neither a star nor a planet, existing in a category in-between. This particular brown dwarf’s mass, however, is just at the threshold between being a Jupiter-like planet and a brown dwarf. It has thus also been called a free-floating, or rogue, planet, not bound to a star. Using the James Webb Space Telescope (JWST), the team captured subtle changes in light from SIMP 0136, revealing complex, evolving weather patterns across its surface.

“Despite the fact that right now we cannot directly image habitable planets around other stars, we can develop methods of learning about the meteorology and atmospheric composition on very similar worlds,” said Roman Akhmetshyn, a McGill MSc student in physics and the study's lead author.

New study revises our picture of the most common planets in the galaxy

A new study finds that many “mini-Neptunes”—perhaps the most common planets in the galaxy—are under so much pressure from their heavy atmospheres that the surface is likely compressed solid. Illustration Credit: NASA/JPL-Caltech/R. Hurt (IPAC)

As telescopes have become more powerful, it’s turned out our solar system is not the only game in town: There are millions of other planets out there in the galaxy. 

But we’re still teasing out clues about what they are actually like. 

One of the puzzles is a kind of planet that appears to be one of the most common types in the universe. Known as “mini-Neptunes” because they run a little smaller than Neptune in our solar system, these planets are made of some mix of rock and metal, with thick atmospheres mostly made of hydrogen, helium, and perhaps water. Strangely, despite their abundance elsewhere, they have no analogue in our own solar system, making the population something of an enigma. 

But a new study published Nov. 5, led by Prof. Eliza Kempton with the University of Chicago, adds a new wrinkle to our best picture yet of these distant worlds.

X-Ray Study Reveals New Details About Betelgeuse’s Elusive Companion Star

Betelbuddy, the companion star to Betelgeuse. This image is a color composite made from exposures from the Digitized Sky Survey 2.
Image Credit: ESO/Digitized Sky Survey 2. Acknowledgment: Davide De Martin

Astronomers have long suspected that Betelgeuse — the bright red star blazing in Orion's shoulder — wasn't alone. Now, thanks to a fleeting cosmic window and swift action by Carnegie Mellon University researchers, the true nature of its elusive companion has been illuminated.

In a race against time, the CMU researchers secured director’s discretionary time on both NASA’s Chandra X-ray Observatory and the Hubble Space Telescope to investigate the long-predicted — but never detected — companion star to Betelgeuse. The timing was critical: Around Dec. 6, the companion, nicknamed “Betelbuddy,” reached its maximum separation from the massive red supergiant just before it would disappear behind it for two more years.

“It turns out that there had never been a good observation where Betelbuddy wasn't behind Betelgeuse,” said Anna O’Grady, a McWilliams Postdoctoral Fellow at Carnegie Mellon’s McWilliams Center for Cosmology and Astrophysics. “This represents the deepest X-ray observations of Betelgeuse to date.”

Moon-forming disc around massive planet

An artistic rendering of a dust and gas disc encircling the young exoplanet, CT Cha b, 625 light-years from Earth. Spectroscopic data from the NASA/ESA/CSA James Webb Space Telescope suggest the disc contains the raw materials for moon formation. The planet appears at lower right, while its host star and surrounding protoplanetary disc are visible in the background. 
Image Credit: NASA, ESA, CSA, STScI, G. Cugno (University of Zürich, NCCR PlanetS), S. Grant (Carnegie Institution for Science), J, Olmsted (STScI), L. Hustak (STScI)

The NASA/ESA/CSA James Webb Space Telescope has provided the first direct measurements of the chemical and physical properties of a potential moon-forming disc encircling a large exoplanet. The carbon-rich disc surrounding the world called CT Cha B, which is located 625 light years away from Earth, is a possible construction yard for moons, although no moons are detected in the Webb data.

Our Solar System contains eight major planets, and more than 400 known moons orbiting six of these planets. Where did they all come from? There are multiple formation mechanisms. The case for large moons, like the four Galilean satellites around Jupiter, is that they condensed out of a dust and gas disc encircling the planet when it formed. But that would have happened over 4 billion years ago, and there is scant forensic evidence today.

UP-led astronomy research team explores formation of giant radio galaxies

An artistic representation of a what a giant cosmic jet the size of the distance between the Milky Way and Andromeda could look like
Illustration Credit: Courtesy of University of Pretoria

Enabled by supercomputing, University of Pretoria (UP) researchers have led an international team of astronomers that has provided deeper insight into the entire life cycle (birth, growth and death) of giant radio galaxies, which resemble “cosmic fountains” – jets of superheated gas that are ejected into near-empty space from their spinning supermassive black holes.

The findings of this breakthrough study were published in the journal Astronomy & Astrophysics, and challenge known theoretical models by explaining how extragalactic cosmic fountains grows to cover such colossal distances, raising new questions about the mechanisms behind these vast cosmic structures.

The research team – which was led by astrophysicist Dr Gourab Giri, who holds a postdoctoral fellowship from the South African Radio Astronomy Observatory at UP –  consisted of Associate Professor Kshitij Thorat and Extraordinary Professor Roger Deane of UP’s Faculty of Natural and Agricultural Sciences; Prof Joydeep Bagchi of Christ University in India; Prof DJ Sailkia of the Inter-University Centre for Astronomy and Astrophysics, also in India; and Dr Jacinta Delhaize of the University of Cape Town (UCT).

This study tackles a key question in modern astrophysics: how these structures, which are larger than galaxies and are made up of black hole jets, interact over cosmological timescales with their very thin, gaseous surroundings. 

SwRI models pluto-charon formation scenario that mimics earth-moon system

Using advanced models, SwRI led new research that indicates that the formation of Pluto and Charon may parallel that of the Earth-Moon system. In the resulting 'kiss-and-captureâ regime, Pluto and Charon collide and stick together in the shape of a snowman. They rotate as one body until Pluto pushes Charon out into a stable orbit.
Image Credit: Courtesy of SwRI/Adeene Denton/Robert Melikyan

A NASA postdoctoral researcher at Southwest Research Institute has used advanced models that indicate that the formation of Pluto and Charon may parallel that of the Earth-Moon system. Both systems include a moon that is a large fraction of the size of the main body, unlike other moons in the solar system. The scenario also could support Pluto’s active geology and possible subsurface ocean, despite its location at the frozen edge of the solar system.

“We think the Earth-Moon system initiated when a Mars-sized object hit the Earth and led to the formation of our large Moon sometime later,” said Dr. Adeene Denton, who led the research, published in Nature Geoscience. “In comparison, Mars has two tiny moons that look like potatoes, while the moons of the giant planets make up a small fraction of their total systems.”

Scientists Have Detailed the Nature of the Darkest Gamma-ray Burst in the Universe

Objects like GRB 150309A tend to be located deep within galaxies.
Photo Credit: Graham Holtshausen

An international group of scientists has presented the results of a detailed spectral analysis of the instantaneous and residual X-ray emission (afterglow) from the intense two-episode dark gamma-ray burst GRB 150309A. The researchers' task was to determine the nature of the instantaneous emission and the composition of the jet ejected in the burst. In addition, based on optical and X-ray spectral analysis of the energy distribution, the researchers performed modeling of the parent galaxy of GRB 150309A to study the surrounding interstellar medium in which this outburst occurred. The results of the analysis are presented in a paper published in the journal Astronomy and Astrophysics.

A bright flash GRB 150309A lasting about 52 seconds was detected on March 9, 2015, by the Gamma-ray Burst Observatory of the Fermi Gamma-ray Space Telescope, a space observatory in low Earth orbit. The event consisted of two bursts: about 200 seconds after the first, more powerful burst, an episode of faint and quiet emission followed.

Despite the strong gamma-ray emission, optical observations with the BOOTES (Burst Observer and Optical Transient Exploration System) and GTC (Gran Telescopio Canarias) telescopes were inconclusive: only the parent galaxy of the outburst signal was detected at optical wavelengths. The X-ray afterglow of GRB 150309A was detected about 5.2 hours after the outburst by the CIRCE instrument installed on the GTC at the Spanish La Palma Observatory.

The optical inaccessibility under intense gamma-ray emission and the intense red X-ray afterglow detected in the near-infrared with CIRCE led scientists to suggest that GRB 150309A belongs to a subclass of dark bursts.