Latest news with #LittleRedDots
News18
23-07-2025
- Science
- News18
Are These 'Little Red Dots' The Universe's First Stars And Not Galaxies?
Last Updated: JWST spotted over 300 mysterious red dots from the early universe. Though once thought to be galaxies, scientists now believe they may be massive stars, not galaxies The James Webb Space Telescope (JWST) has realised humanity's ambition of observing the early universe. It recently transmitted images from when the universe was merely 600 million years old. However, these images revealed something puzzling: hundreds of small red spheres, now referred to as Little Red Dots (LRDs). JWST identified over 300 of these red dots. Despite being faint and extremely distant, they appear unusually bright, suggesting a very high mass. Initially, scientists believed these were early galaxies, but new research proposes a surprising alternative: they may actually be supermassive stars (SMS), not galaxies. A recent study by Devesh Nandal of the University of Virginia and Abraham Loeb of Harvard suggests these mysterious LRDs could be Population III supermassive stars; stars that formed in the very early universe. These stars contained no metals and could have masses up to 1 million times that of our Sun. However, they lived for only a few thousand years before exploding as supernovae. These explosions may have contributed to the formation of the first supermassive black holes (SMBHs), which are now found at the centres of quasars and large galaxies. The red appearance of LRDs is due to the thick clouds of gas and dust surrounding them. Initially, scientists speculated they might be active galactic nuclei (AGN), with black holes at their centres. However, key differences such as the absence of X-ray emissions, a flat infrared spectrum, and minimal light variation challenged that theory, prompting researchers to consider alternative explanations. What Did the Research Find? Nandal and Loeb created a model of a metal-free supermassive star with a mass of one million Suns. They found that its light spectrum and brightness closely matched those of the LRDs observed by JWST. Most importantly, the model showed a strong Hβ emission line and Balmer absorption lines, features typically created when gas expands on the surface of a supermassive star. This strongly supports the theory that LRDs are not galaxies but giant stars. Could This Solve a Cosmic Mystery? If proven true, this theory could help solve a long-standing puzzle: how did SMBHs form so soon after the Big Bang? According to current models, they should have taken billions of years to develop. However, the presence of quasars and SMBHs just a few hundred million years after the Big Bang contradicts this. The theory of short-lived, massive stars collapsing into black holes provides a much simpler explanation. The researchers adhered to the principle of Occam's Razor, the idea that the simplest explanation is often the most likely. While the AGN theory requires multiple complex assumptions, the SMS model explains all the observed features straightforwardly. Nevertheless, scientists emphasise that this is still a developing theory. Further telescopic observations and improved modelling will be necessary to confirm whether these Little Red Dots are indeed ancient supermassive stars. Despite the limitations of current technology, JWST has opened a new window into the universe's earliest moments – and potentially, into one of its greatest mysteries. First Published: Disclaimer: Comments reflect users' views, not News18's. Please keep discussions respectful and constructive. Abusive, defamatory, or illegal comments will be removed. News18 may disable any comment at its discretion. By posting, you agree to our Terms of Use and Privacy Policy.
Hans India
30-05-2025
- Science
- Hans India
JWST uncovers new kind of black holes linking classical quasars and 'Little Red Dots'
Astronomers have identified a previously unseen class of supermassive black holes in the early universe by combining Subaru Telescope data with follow-up observations from the James Webb Space Telescope (JWST). These dust-enshrouded quasars, dating to within the first billion years after the Big Bang, bridge the gap between well-known, brightly shining quasars and the faint 'Little Red Dots' JWST first spotted in late 2022. For over a decade, ground-based surveys with Subaru flagged galaxies whose light signatures hinted at more than just star formation, but technical limits prevented a definitive identification. By re-examining 13 of these candidates using JWST's sensitive infrared spectrograph, an international team detected the telltale broad emission lines and high-velocity gas flows that confirm active galactic nuclei powered by supermassive black holes cloaked in heavy dust. Of those 13 galaxies, nine revealed these hidden quasars, whose intrinsic brightness rivals that of classical quasars but whose optical light is heavily reddened by surrounding dust—mirroring the characteristics of the 'Little Red Dots.' Lead author Yoshiki Matsuoka of Ehime University remarked, 'We were surprised to find that obscured quasars are so abundant in the early universe,' suggesting that many young black holes have eluded detection in previous surveys. Independent expert Jorryt Matthee of IST Austria, who was not involved in the study, praised the robustness of the spectral data and noted that this new population likely represents the 'missing link' between the rare, brilliant quasars and the smaller, dimmer red dots. As more of these objects are confirmed, astronomers will be able to estimate the masses of their black holes and host galaxies, offering fresh insights into how the earliest galactic giants grew. Building on these promising results, Matsuoka's team plans to use JWST to study roughly 30 more Subaru-selected targets. By mapping the environments and gas dynamics around these hidden quasars, researchers hope to unravel the origins of the Little Red Dots and refine our understanding of black-hole evolution at cosmic dawn.
Yahoo
30-05-2025
- General
- Yahoo
James Webb telescope uncovers new, 'hidden' type of black hole never seen before
When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers using the James Webb Space Telescope (JWST) have unveiled a hidden population of supermassive black holes in the early universe that have never been seen before. This fascinating discovery could bridge the gap between classical quasars and the lesser-known "Little Red Dots" recently detected near the dawn of time, which may represent baby quasars. Classical quasars are active galactic nuclei (AGNs), galaxies dominated by actively-feeding black holes that are surrounded by complex dust environments. These AGNs are powered by large supermassive black holes and are extremely bright, which makes them easily detectable despite the surrounding dust. But in December 2022, scientists using JWST discovered a strange new type of AGN that they dubbed Little Red Dots — so named because they look like tiny, faint red spots in images. In contrast to classical quasars, these dots are smaller and dimmer, and they tend to be hidden by a lot of dust. The connection between the two AGN types remains a mystery, prompting astronomers to search for objects with intermediate properties. For more than a decade, astronomers have been looking out for distant quasars with the Subaru Telescope in Hawaii, and have identified several galaxies within the first billion years after the Big Bang. While the light from these galaxies was not typical of a classical quasar, the intensity of light was too high to be due to star formation alone. They suspected that these galaxies harbored AGNs, which were somehow hidden in dust. But astronomers could not prove that they were indeed a different type of AGN due to technical limitations in telescopes at the time. Related: James Webb telescope discovers frozen water around a distant, sunlike star Now, using the more sensitive JWST to reanalyze those puzzling objects spotted by Subaru, an international team of astronomers has confirmed the presence of fast-moving gas under the influence of the strong gravity of supermassive black holes. This proved that the objects were AGNs after all — but a type never seen before. The findings were reported on May 7 in a study uploaded to the preprint database arXiv. Out of 13 distant galaxies examined in the new study, astronomers found that 9 displayed clear signs of a new population of active, supermassive black holes — and their patterns of light carry the unmistakable fingerprint of quasars hidden behind heavy dust. "We were surprised to find that obscured quasars are so abundant in the early universe," Yoshiki Matsuoka, associate professor at the Research Center for Space and Cosmic Evolution at Ehime University, and lead author of the study, told Live Science in an email. "This means that a significant fraction of active [supermassive black holes] have been overlooked in the past ground-based surveys." These newly discovered "hidden" quasars are as bright as classical quasars, but the level of dust obscuring their light resembles what astronomers have found in the case of Little Red Dots. Combining the ground-based data with JWST's detailed follow-up observations, researchers may have found the missing link between rare, bright quasars and the more common Little Red Dots seen by JWST. "These results are robust due to the high-quality of the light spectra of these objects, with clear signatures of gas powered by supermassive black holes," Jorryt Matthee, assistant professor and head of the research group Astrophysics of Galaxies at the Institute of Science and Technology Austria, who was not involved in the new study, told Live Science. "While the number of new objects is high, it is not so unexpected," Matthee said. "The gap between the two known populations is very vast, and indeed, these new objects may belong to that missing population, but there's probably more." He adds that as astronomers find more of these hidden quasars and gather additional observations, the light they emit can be used to estimate the masses of stars and supermassive black holes in their host galaxies. This information will offer fresh insights into how these giants evolved in the early universe. Additionally, by comparing the number of hidden quasars discovered with what theoretical models predict, scientists can test whether these findings challenge the standard model of the universe. RELATED STORIES —'Baby quasars' spotted by James Webb telescope could transform our understanding of monster black holes —Astronomers find hundreds of 'hidden' black holes — and there may be billions or even trillions more —James Webb telescope spots rare 'missing link' galaxy at the dawn of time Meanwhile, the team led by Matsuoka plans to use JWST to observe 30 more objects from the same Subaru Telescope sample. They are hoping to uncover more hidden quasars, including Little Red Dots. First reported just a few years ago, Little Red Dots are still shrouded in mystery. They're poorly understood because they appear so faint and tiny in the sky. Matsuoka explained that by combining their results with other follow-up observations to study the surrounding gas and environments, the hidden quasars will provide a vital clue to unveiling the mysterious nature of Little Red Dots.
