Scientists Working to Decode Signal From Earliest Years of Universe
As mysterious as the Big Bang that gave birth to the universe is the brief but tumultuous period that immediately followed it. How did the cosmos transform from a uniform sea of darkness into a chaotic swirl brimming with radiant stars? What were these first stars like, and how were they born?
So far, we have very strong suspicions, but no hard answers. One reason is that the light from this period, called the cosmic dawn, is extremely faint, making it nearly impossible to infer the traits of these first cosmic objects, let alone directly observe them.
But that's about to change, according to a team of international astronomers. In a new study published in the journal Nature Astronomy, the astronomers argue that we're on the verge of finally decoding a radio signal that was emitted just one hundred millions years after the Big Bang. Known as the 21 centimeter signal, which refers to its distinct wavelength, this burst of radiation was unleashed as the inchoate cosmos spawned the earliest stars and black holes.
"This is a unique opportunity to learn how the universe's first light emerged from the darkness," said study co-author Anastasia Fialkov, an astronomer from the University of Cambridge in a statement about the work. "The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand."
After several hundred thousand years of cooling following the Big Bang, the first atoms to form in the universe were overwhelmingly neutral hydrogen atoms made of one positively charged proton and one negatively charged electron.
But the formation of the first stars unbalanced that. As these cosmic reactors came online, they radiated light energetic enough to reionize this preponderance of neutral hydrogen atoms. In the process, they emitted photons that produced light in the telltale 21 centimeter wavelength, making it an unmistakeable marker of when the first cosmic structures formed. Deciphering these emissions would be tantamount to obtaining a skeleton key to the dawn of the universe.
And drum roll, please: employing the Radio Experiment for the Analysis of Cosmic Hydrogen telescope, which is currently undergoing calibration, and the enormous Square Kilometer Array, which is under construction Australia, the researchers say they've developed a model that can tease out the masses of the first stars, sometimes dubbed Population III stars, that are locked inside the 21 centimeter signal.
While developing the model, their key revelation was that, until now, astronomers weren't properly accounting for the impact of star systems called x-ray binaries among these first stars. These are systems where a black hole or neutron star is stripping material off a more ordinary star that's orbiting it, producing light in the x-ray spectrum. In short, it appears that x-ray binaries are both brighter and more numerous than what was previously thought.
"We are the first group to consistently model the dependence of the 21-centimeter signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die," said Fialkov. "These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang."
All told, it's another promising leap forward in the field of radio astronomy, where recent advances have begun to reveal an entire "low surface brightness" universe — and a potentially profound one as well, with the promise to illuminate our understanding of the cosmic dawn as never never before.
"The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the universe," said co-author Eloy de Lera Acedo, a Cambridge astronomer and a principal investigator of the REACH telescope. "We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars."
More on astronomy: Scientists Investigating Small Orange Objects Coating Surface of the Moon
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Novo Nordisk A/S: CagriSema 2.4 mg / 2.4 mg demonstrated 22.7% mean weight reduction in adults with overweight or obesity in REDEFINE 1, published in New England Journal of Medicine
Data presented simultaneously at the American Diabetes Association's® 85th Scientific Sessions, showed mean weight reduction in the highest range of efficacy observed with existing weight loss interventions1 When adhering to treatment, weight loss of ≥5%, ≥20%, ≥25%, and ≥30% was observed in 97.6%, 60.2%, 40.4% and 23.1% of patients respectively at 68 weeks1* The REDEFINE clinical programme is ongoing to further investigate efficacy and safety of CagriSema, including recently initiated REDEFINE 112 Bagsværd, Denmark, 22 June – Today, The New England Journal of Medicine (NEJM) published results from Novo Nordisk's phase 3 REDEFINE 1 trial evaluating the efficacy and safety of investigational CagriSema plus lifestyle interventions for weight loss in adults with obesity or overweight who have a weight-related medical complication and without diabetes.1 REDEFINE 1 met its co-primary endpoints and achieved statistically significant and clinically meaningful weight loss at 68 weeks in patients taking CagriSema versus placebo.1 These data, along with the related phase 3 REDEFINE 2 study conducted in adults with overweight or obesity and type 2 diabetes, were presented today during a scientific symposium at the American Diabetes Association's (ADA) 85th Scientific Sessions and published in NEJM. 'In REDEFINE 1, participants saw significant and clinically meaningful weight loss under a protocol that allowed investigators to maintain patients on a submaximal dose if deemed best for the patient. We also witnessed low, single-digit discontinuation rates due to adverse events in both REDEFINE 1 and 2,' said Martin Holst Lange, executive vice president and head of Development at Novo Nordisk. 'These results reinforce our confidence in CagriSema, and we continue to study the potential of this combination through the REDEFINE trials.' CagriSema is an investigational product that combines the GLP-1 RA, semaglutide, with an amylin analogue, cagrilintide. The REDEFINE 1 trial found that treatment with CagriSema resulted in greater weight loss of 22.7% at 68 weeks versus 2.3% in the placebo group if all patients adhered to treatment.1* When evaluating the treatment effect regardless of adherence, those treated with CagriSema achieved statistically significant weight loss of 20.4% at 68 weeks versus 3.0% for the placebo group.1** In addition, a supportive secondary analysis showed that half (50.7%) of trial participants with obesity treated with CagriSema reached the threshold for non-obesity (BMI < 30 kg/m2) at the end of treatment, from a mean BMI of 38 kg/m2 at the start of treatment. 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Most recently, Novo Nordisk initiated the REDEFINE 11 trial with the first patient visit occurring in early June 2025. REDEFINE 11 will explore further weight loss potential and safety of CagriSema 2.4 mg / 2.4 mg through a longer trial duration and other protocol changes compared to REDEFINE 1 and 2. * Based on the trial product estimand; this estimand estimates what the effect would be if all participants adhered to treatment ** Based on the treatment policy estimand: treatment effect regardless of treatment adherence About CagriSemaCagriSema is being investigated by Novo Nordisk as a once-weekly subcutaneous injectable treatment for adults with overweight or obesity (REDEFINE programme) and as a treatment for adults with type 2 diabetes (REIMAGINE programme). CagriSema is a fixed-dose combination of a long-acting amylin analogue, cagrilintide 2.4 mg and semaglutide 2.4 mg. About the REDEFINE clinical trial programmeREDEFINE is a phase 3 clinical development programme with once-weekly subcutaneous CagriSema in obesity. REDEFINE 1 and REDEFINE 2 have enrolled approximately 4,600 adults with overweight or obesity. REDEFINE 1 was a double-blind, placebo-and active-controlled 68-week efficacy and safety phase 3 trial of once-weekly CagriSema, cagrilintide 2.4 mg and semaglutide 2.4 mg versus placebo in 3,417 adults with obesity or overweight with one or more comorbidities and without type 2 diabetes. REDEFINE 2 was a double-blind, randomized, placebo- and controlled 68-week efficacy and safety phase 3 trial of once-weekly CagriSema versus placebo in 1,206 adults with type 2 diabetes and either obesity or overweight. Multiple REDEFINE clinical trials are currently underway including: REDEFINE 3, an event-driven cardiovascular outcomes phase 3 trial; REDEFINE 4 an 84-week head-to-head efficacy and safety phase 3 trial of once-weekly CagriSema versus once-weekly tirzepatide; and REDEFINE 11, a phase 3 trial with longer duration and other protocol changes compared to REDEFINE 1 and 2. About obesity Obesity is a serious chronic, progressive, and complex disease that requires long-term management.4-6 One key misunderstanding is that this is a disease of just lack of willpower, when in fact there is underlying biology that may impede people with obesity from losing weight and keeping it off.4,6 Obesity is influenced by a variety of factors, including genetics, social determinants of health, and the environment.7,8 Novo Nordisk is a leading global healthcare company founded in 1923 and headquartered in Denmark. Our purpose is to drive change to defeat serious chronic diseases built upon our heritage in diabetes. We do so by pioneering scientific breakthroughs, expanding access to our medicines, and working to prevent and ultimately cure disease. Novo Nordisk employs about 77,400 people in 80 countries and markets its products in around 170 countries. For more information, visit Facebook, Instagram, X, LinkedIn and YouTube. Contacts for further information Media: Ambre James-Brown +45 3079 9289 abmo@ Liz Skrbkova (US) +1 609 917 0632 lzsk@ Investors: Jacob Martin Wiborg Rode +45 3075 5956 jrde@ Ida Schaap Melvold +45 3077 5649 idmg@ Sina Meyer +45 3079 6656 azey@ Max Ung +45 3077 6414 mxun@ Frederik Taylor Pitter +1 609 613 0568 fptr@ References: Garvey WT, Blüher MD, Contreras CKO, et al. CagriSema in Adults with Overweight or Obesity. New England Journal of Medicine 2025. doi: 10.1056/NEJMoa2502081 A Research Study to Look at How Well CagriSema Helps People Living With Obesity Lose Weight and Maintain Weight Loss in the Long-term. Last Accessed: June 2025. Available at: Davies MJ, Harpreet S, Bajaj MD, et al. CagriSema in Adults with Overweight or Obesity and Type 2 Diabetes. New England Journal of Medicine 2025. Kaplan LM, Golden A, Jinnett K, et al. Perceptions of barriers to effective obesity care: results from the national action study. Obesity. 2018;26(1):61-69. Bray GA, Kim KK, Wilding JPH; World Obesity Federation. Obesity: a chronic relapsing progressive disease process. A position statement of the World Obesity Federation. Rev. 2017;18(7):715-723. Garvey WT, Mechanick JI, Brett EM, et al. American association of clinical endocrinologists and American College of Endocrinology comprehensive clinical practice guidelines for medical care of patients with obesity. Endocr Pract. 2016;22 (Suppl 3):1-203. Centers for Disease Control and Prevention. Adult obesity facts. Last accessed: June 2025. Available at: World Obesity Federation. World Obesity Atlas 2023. Last accessed: June 2025. Available at: Attachment PR250622-ADA-CagriSema
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Yahoo
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A radio signal from the beginning of the universe could reveal how everything began
A radio signal from the early universe could allow us to understand how everything that surrounds us began. The signal – known as the 21-centimetre signal – could finally let us understand how the first stars and galaxies switched on, and brought the universe from darkness to light. 'This is a unique opportunity to learn how the universe's first light emerged from the darkness,' said co-author Anastasia Fialkov from Cambridge University, in a statement. 'The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand.' The signal comes to us from more than 13 billion years ago, just a hundred million years after the Big Bang. The faint glow is created by hydrogen atoms that fill up the space between regions of space where stars are being formed. Scientists now believe they will be able to use the nature of that signal to better understand the early universe. They will do that with a radio antenna called REACH – the Radio Experiment for the Analysis of Cosmic Hydrogen – which will try and capture radio signals to reveal data about the beginnings of the universe. To better understand how that project might work, researchers created a model that predicted how REACH as well as another project called the Square Kilometre Array will be able to provide information about the masses and other details of the first stars. 'We are the first group to consistently model the dependence of the 21-centimetre signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die,' said Professor Fialkov. 'These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang.' 'The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the Universe,' said co-author Eloy de Lera Acedo, Principal Investigator of the REACH telescope. 'We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars. 'Radio telescopes like REACH are promising to unlock the mysteries of the infant Universe, and these predictions are essential to guide the radio observations we are doing from the Karoo, in South Africa.' The work is described in a new paper, 'Determination of the mass distribution of the first stars from the 21-cm signal', published in the journal Nature Astronomy.
