All posts tagged: astrophysics

Did the Webb Telescope really find signs of life on an exoplanet?

Did the Webb Telescope really find signs of life on an exoplanet?

After exciting reports last year, did the James Webb Space Telescope actually find signs of life on an exoplanet? In 2023, NASA’s flagship telescope identified biosignature gas in the atmosphere of an exoplanet called K2-18b, indicating signs of life. The findings inferred that K2-18b, which is located 120 light years away from Earth, had several conditions that could support life as we know it. However, despite the news sparking significant excitement among the scientific community and public alike, new research from UC Riverside suggests the findings may not indicate alien life. Well, not yet. K2-18b’s composition Most exoplanets are not comparable to Earth, as their temperatures, atmosphere, and climates cannot support life as we know it on Earth. K2-18b, on the other hand, is different. This exoplanet receives around the same amount of solar radiation as Earth. Moreover, if the atmosphere is removed as a factor, K2-18b has a similar temperature to our planet. The exoplanet’s atmosphere is predominantly hydrogen, whereas Earth’s is nitrogen. Signs of water The findings fuelled speculation that there are oceans …

The Mysterious ‘Dark’ Energy That Permeates the Universe Is Slowly Eroding

The Mysterious ‘Dark’ Energy That Permeates the Universe Is Slowly Eroding

Beyond DESI, a slew of new instruments are coming online in the coming years, including the 8.4-meter Vera Rubin Observatory in Chile, NASA’s Nancy Grace Roman Space Telescope, and the European Space Agency’s Euclid mission. “Our data in cosmology has made enormous leaps over the last 25 years, and it’s about to make bigger leaps,” Frieman said. As they amass new observations, researchers may continue to find that dark energy appears as constant as it has for a generation. Or, if the trend continues in the direction suggested by DESI’s results, it could change everything. New Physics If dark energy is weakening, it can’t be a cosmological constant. Instead, it may be the same sort of field that many cosmologists think sparked a moment of exponential expansion during the universe’s birth. This kind of “scalar field” could fill space with an amount of energy that looks constant at first—like the cosmological constant—but eventually starts to slip over time. “The idea that dark energy is varying is very natural,” said Paul Steinhardt, a cosmologist at Princeton …

Supermassive black holes may provide a nursery for mini ones to grow

Supermassive black holes may provide a nursery for mini ones to grow

We may have a clearer understanding of why the accretion disc around large black holes is so bright Dana Berry/SkyWorks Digital/NASA Thousands of relatively small black holes may be circling the supermassive black holes that lurk at the centres of galaxies. The idea would not only help explain how small black holes grow larger, it would also give us a new understanding of why supermassive black holes appear so bright. The centres of galaxies are extraordinarily dense, so matter – including relatively small, or stellar-mass, black holes – tends to accumulate there. Some of… Source link

A circular space economy is more than just rocket science

A circular space economy is more than just rocket science

In the North East of England, industry and academia have joined forces to develop the relevant skills to enable a truly circular space economy. Through the work of companies such as 3S Northumbria, the idea of a circular economy for human operations in outer space has gained increasing traction. The idea of minimising waste and maximising the use of resources through reuse, recycling, and repurposing offers a tangible, sustainable future for humanity as it looks to transition into a spacefaring species. Therefore, establishing a skilled workforce capable of driving this circular economy in space is crucial. The North East of England emerges as an ideal hub for nurturing and developing the skills, and more importantly, the mindset, for delivering such a fundamental element of sustainable space operations. The region has a rich tradition of innovation, resilience, and adaptability amongst the workforce, which can be seen through its industrial heritage rooted in shipbuilding, steelworking, and coal mining. Academic collaboration Yet, the past is not the only consideration when developing the necessary skills to explore and exploit …

Physics of extreme massive stars

Physics of extreme massive stars

Massive stars in extreme evolutionary stages have been studied to reveal their pulsation and mass loss properties, indispensable for the understanding of stellar and galactic evolution. One of the most important, long-standing questions in astrophysics is: How do massive stars evolve from their birth up to supernova explosion? Massive stars are powerful cosmic engines. Throughout their entire lifetime, they enrich their environment with huge amounts of energy and chemically processed material. The energy released from massive stars is so powerful that it can trigger the formation of new generations of stars and planets. The chemical elements produced inside stars and released to their environment via winds and eruptions are the building blocks of all life as we know it on Earth. Despite the importance of massive stars for cosmic evolution, their aging process from the cradle to their death as spectacular supernova explosions still faces many uncertainties. The EU-funded project POEMS aimed to remove some of them, in particular in relation to precise mass-loss predictions in various late evolutionary stages that were so far hampering …

I might be an astrophysicist, but I’m still learning about stargazing

I might be an astrophysicist, but I’m still learning about stargazing

ON 8 APRIL, a total solar eclipse will be visible from various parts of North America. The path in which this will occur runs from Mexico, diagonally across the US and into the Atlantic region of Canada. Eclipses like this, where the moon moves directly between the sun and Earth and blocks out light, happen almost every 20 years. But our planet is a big place, and these events can’t be seen everywhere. Only about once every 400 years is one visible from any given spot on Earth. Which is to say, those of us in or near the… Source link

Tiniest starquakes ever detected in new study

Tiniest starquakes ever detected in new study

A team of international scientists has measured the tiniest starquakes from an orange dwarf star. The star, called Epsilon Indi, is the smallest and coolest dwarf star observed with solar-like oscillations, or starquakes, like those shown by the Sun. These oscillations provide indirect glimpses of stellar interiors, just as earthquakes tell us about Earth’s interior. Because of this, they are important sources of information about stars. The measurements were taken by an international team led by the Institute of Astrophysics and Space Sciences in Portugal. The study is published in Astronomy and Astrophysics Letters. Starquakes detected using asteroseismology The team detected the starquakes using a technique called asteroseismology. This measures oscillations in stars. Using the ESPRESSO spectrograph, the team recorded the oscillations with unprecedented precision. Lead author Tiago Campante, of the Institute of Astrophysics and Space Sciences at the University of Porto, said: “The extreme precision level of these observations is an outstanding technological achievement. “Importantly, this detection conclusively shows that precise asteroseismology is possible down to cool dwarfs with surface temperatures as low as …

Most newborn black holes spew gas so hard they almost stop spinning

Most newborn black holes spew gas so hard they almost stop spinning

Jets of plasma may slow down the spins of black holes NASA/JPL-Caltech Most black holes may spin far more slowly than expected. When black holes form from collapsing stars, they emit powerful jets of energy, and these jets slow down the black holes’ spin to nearly nothing within minutes. The spin of a newborn black hole is governed by two competing phenomena. When fast-moving material in its orbit falls in, the black hole takes in energy and its rotation speeds up. But that same consumption causes a huge jet to blast away… Source link

Mysterious object may be the lightest black hole we’ve ever seen

Mysterious object may be the lightest black hole we’ve ever seen

An artist’s impression of a pulsar orbiting a black hole – one possible interpretation of the mysterious binary system Daniëlle Futselaar (artsource.nl) A strange object about 40,000 light years away is either the heaviest neutron star or the lightest black hole we have ever seen, sitting in a mysterious void of objects that astronomers have never directly observed. A neutron star forms when a star has run out of fuel and collapses under its gravity, creating a shockwave called a supernova and leaving an ultra-dense core behind. According to astrophysical calculations, these cores must remain below a certain mass, around 2.2 times the mass of the sun, or they will collapse even further, creating a black hole. However, black holes have only been observed with a mass more than five times that of the sun, leaving a gap in scale between neutron stars and black holes. There have been some dense objects observed in this gap by gravitational wave observatories, but astronomers have never spotted them with conventional telescopes. Now, Ewan Barr at the Max …

Mysterious object may be the heaviest neutron star ever seen

Mysterious object may be the heaviest neutron star ever seen

Neutron stars are the collapsed cores of massive stars www.science.org/doi/10.1126/science.adg3005 A strange object about 40,000 light years away is either the heaviest neutron star or the lightest black hole we have ever seen, sitting in a mysterious void of objects that astronomers have never directly observed. A neutron star forms when a star has run out of fuel and collapses under its gravity, creating a shockwave called a supernova and leaving an ultra-dense core behind. According to astrophysical calculations, these cores must remain below a certain mass, around 2.2 times the mass of the sun, or they will collapse even further, creating a black hole. However, black holes have only been observed with a mass more than five times that of the sun, leaving a gap in scale between neutron stars and black holes. There have been some dense objects observed in this gap by gravitational wave observatories, but astronomers have never spotted them with conventional telescopes. Now, Ewan Barr at the Max Planck Institute for Radio Astronomy in Germany and his colleagues have spotted …