Researchers accidentally discovered a third exoplanet around the star Betelgeuse. This planet is the dimmest among exoplanets photographed from Earth and belongs to the group of least massive bodies ever recorded by ground-based telescopes. The discovery of Betelgeuse d helps explain the frequency of exokomet transits and the structure of the debris disk around the star.
Direct observation of exoplanets is a highly effective method for determining their characteristics. However, the application of this methodology has only become possible in recent decades because it requires the use of powerful telescopes and highly sensitive radiation receivers. Thanks to such observations, large exoplanets and brown dwarfs on vast orbits inaccessible to other methods can be identified, as well as developing protoplanets and the dynamics of multi-planet systems can be studied.
A team of astronomers, led by Ben Satliffe from the University of Edinburgh and Marcus Bonse from the European Southern Observatory, announced the discovery of the third exoplanet around Betelgeuse. The planet was spotted in direct images of the system obtained using the SPHERE and ERIS receivers installed on the VLT (Very Large Telescope) complex in Chile. Data were collected using James Webb's NIRCam cameras between 2014 and 2025, with observations conducted in the near and mid-infrared ranges.
Betelgeuse is located 63 light-years from the Sun. It is a relatively young A6V type star, estimated to be about 20–26 million years old, and it has long attracted the attention of exoplanetologists. A disk of dust and debris surrounds the star, where collisions of planetesimals occur, and there are candidates for exokomet. Two other exogiant planets have previously been identified in this system: the cloudy super-Jupiter Betelgeuse b (with a mass of about 9.3 Jupiter masses) and Betelgeuse c (with a mass of about 8.89 Jupiter masses).
The discovery of Betelgeuse d was accidental, as the scientists' initial goal was to refine the parameters of already known exoplanets. A new point source of light appeared southwest of the star in the images, which was not visible in the archival data of the NaCo receiver on VLT for the period from 2003 to 2015 due to insufficient sensitivity. Analysis of the proper motion of this source confirmed that it is a body gravitationally bound to the star, not a background galaxy or star. The calculated orbit of the planet is close to the orbits of the other two exoplanets in the system, with a semi-major axis of 26 astronomical units, an inclination of 89 degrees, an eccentricity of less than 0.44, and an orbital period of 91 years.
Scientists concluded that Betelgeuse d matches the model of an exogiant with a calculated mass of 2.4 Jupiter masses, a radius of 1.26 Jupiter radii, and an effective temperature of 600 Kelvin. The planet is characterized by low luminosity, shows clear traces of carbon dioxide in its atmosphere, and has higher metallicity compared to rogue exoplanets. The 'hot start' model, which assumes rapid planet formation through gravitational instability in the protoplanetary disk, was used to calculate the properties. However, the low luminosity is also consistent with the 'cold start' model, where the planet forms by accumulating matter around a solid core in the circumstellar disk. If the second hypothesis is confirmed, the Betelgeuse system will become the first in which exogiant planets formed by both mechanisms are present. Furthermore, the presence of Betelgeuse d explains the frequent exokomet transits and defines the inner edge of the circumstellar disk.
A potentially most distant galactic bar has been identified using the infrared James Webb Space Telescope. This structure is located in the spiral galaxy M1149-BSG-z5 and existed approximately 1.2 billion years after the Big Bang.
The characteristics of M1149-BSG-z5 suggest that such bars could form quite rapidly in galaxies rich in gas and baryonic matter, especially if they underwent interactions with other galaxies. Access to the study's preprint is available on arXiv.org.
Central bars, or bars, are a characteristic feature of about 60% of disk galaxies within the Local Universe. These structures significantly influence the internal evolution of systems, for example, by regulating the activity of the central nucleus or the rate of star formation. It is hypothesized that bars arise from gravitational instabilities in disks, tidal interactions, or the merger of gas-rich galaxies, but the mechanism and timing of their appearance in the early Universe remain unclear.
To establish stricter boundaries for bar formation models, researchers continue to search for increasingly distant galaxies that possess bars. Previously, the GN20 system was the record holder in this regard.
A group of astronomers led by Wang Xiaohang from Tsinghua University announced the discovery of a new candidate for the most distant galactic bar. This object is observed in the spiral galaxy M1149-BSG-z5, which scientists found near the galaxy cluster MACS J1149+2223 by analyzing data obtained by the NIRCam and NIRISS instruments of the James Webb Telescope, as well as using results from deep observations of the same patch of sky by the Hubble Telescope.
The spectroscopic redshift of M1149-BSG-z5 is 5.1015, allowing us to see the galaxy as it was almost 1.2 billion years after the Big Bang. Lines of ionized oxygen, hydrogen, nitrogen, and sulfur were identified in the spectrum, indicating a noticeable enrichment of the internal medium with metals (approximately half of solar metallicity).
The structure of M1149-BSG-z5 includes two spiral arms diverging from the bar; a bright clump was observed in the southeast arm. The galaxy's bulge has an effective radius of 8.5 thousand light-years, and the bar itself is estimated to be about 15 thousand light-years long. The stellar mass of M1149-BSG-z5 reaches $10^{10.45}$ solar masses, and the star formation rate is estimated at 144 solar masses per year. Furthermore, the galaxy's core contains an active black hole with a mass of about $10^{7.5}$ solar masses.
The combination of these characteristics makes the system a massive and mature galaxy with an abnormally large bar that has undergone significant chemical evolution. On one hand, the similarity of M1149-BSG-z5 to an actively developing, gas- and baryonic-matter-rich system may indicate rapid bar formation due to gravitational instabilities in the disk. On the other hand, the galaxy's location in a high-density region and the presence of a presumed galactic companion at a distance of about 69 thousand light-years from M1149-BSG-z5 aligns with a merger or interaction-driven formation model. Future observations are necessary to determine the exact mechanism of this bar's formation.
Scientists used ground-based radio telescopes to detect the presence of erythrose—a sugar found, for example, in raspberries—in the molecular cloud G+0.693-0.027 located in the Milky Way. This finding marks the first registered case of a sugar discovery in the interstellar medium, confirming the hypothesis that such complex prebiotic molecules can form and be preserved in space, from where they may enter the composition of small celestial bodies.
Sugars are critically important molecules for sustaining life because they participate in metabolic processes, act as structural components, and are part of the bases of DNA and RNA nucleic acids. Research into how simple sugars appeared on early Earth is necessary to understand the origin of life on our planet and its potential existence beyond Earth. It is already known that several sugars, including ribose and fructose, have been found in meteorite samples and on the surface of the asteroid Bennu, which, combined with laboratory results, allows for the suggestion that these complex compounds form in the interstellar medium.
To date, only glycolaldehyde—a simple diose classified as a hydroxyaldehyde close to sugars, rather than a true sugar—has been identified in interstellar clouds and comet cores. Difficulties in obtaining rotational spectra of sugars in the gas phase under laboratory conditions were recently overcome by using laser ultrafast evaporation, which allowed for the acquisition of the necessary data for analyzing ribose, 2-deoxyribose, and erythrose.
A group of astronomers led by Isaskun Jimenez-Serrano from the Spanish Astrobiology Center announced the discovery of erythrose in the interstellar medium. The scientists studied the molecular cloud G+0.693-0.027, which is located in the Galactic Central Molecular Zone, approximately 28 thousand light-years from the Sun. Observations were conducted between 2021 and 2024 using the 40-meter radio telescope of the Yepes Observatory and the 30-meter IRAM radio telescope. The cloud G+0.693-0.027 has long attracted the attention of astrochemists due to the presence of many complex molecules significant for living organisms.
Erythrose belongs to the ketoses, has four carbon atoms, and is present in raspberry berries as well as in cosmetic products. It has become the largest acyclic and the second chiral molecule identified in the interstellar medium. Its column density is 8.7 × 10^23 particles per square centimeter, which is similar to the value of glycolaldehyde also found in the cloud. Furthermore, researchers did not find traces of glyceraldehyde and dihydroxyacetone (three-carbon sugars), indicating that erythrose occurs 8–17 times more frequently than these compounds, which is unusual. Glycerin, which could serve as a precursor to erythrose, was also not found.
Researchers believe that erythrose in G+0.693-0.027 may have formed as a result of a chemical reaction between glycolaldehyde radicals and ethylene glycol—both substances are present in the cloud in sufficiently high concentrations. This reaction possibly occurs on the solid surface of amorphous water ice covering dust particles in the interstellar medium, at temperatures characteristic of dust toward the center of the Milky Way (around 20–30 Kelvin).
The discovery of erythrose serves as direct evidence that complex chiral and prebiotic molecules are capable of arising and being preserved in the interstellar medium. In the context of the Solar System, sugars could have formed in the protostellar nebula, after which they entered the composition of small bodies that subsequently bombarded the young Earth. Moreover, ketoses like erythrose can transform into treose and erythrose in an aqueous environment, potentially leading to the appearance of the TRK molecule—a possible precursor to RNA.
It is also worth noting that astronomers have identified a promising candidate for an old, low-mass hypervelocity star leaving the Milky Way for the first time. It is hypothesized that the star DESI-HVS1 was previously part of a binary system that was ejected almost thirteen million years ago as a result of a close encounter with the supermassive black hole at the center of the Milky Way.
