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Category: cosmology – Page 102

The key to understanding our universe lies in two theories—one of the generally-very-big and one of the generally-very-small. Albert Einstein’s Theory of General Relativity explains things like gravity and time, while Quantum Field Theory explores the subatomic world. However, one celestial object frustrates astrophysicists and quantum theorists in equal measure: black holes.

Because black holes release Hawking radiation (named for famous physicist Stephen Hawking), they eventually evaporate, which seemingly destroys the information that fell into the black hole. However, quantum field theory states that information cannot be destroyed. Result? Paradox.

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Scientists have found a star unlike any other one recorded—which may change our understanding of how stars die.

This unusual star, 13,000 light-years away, has an elemental makeup that suggests it was formed in the aftermath of a more massive star exploding in a way that no existing theory seems to explain. According to everything else we know, the original star should have turned into a black hole instead.

The discovery may rearrange our picture of how stars explode and how some of the heavier elements are made. It also helps us better understand what the first generation of stars in the universe may have looked like.

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How is a black hole formed? In the simplest language, a black hole is born when a star dies. Now, astronomers have claimed that they might have just witnessed the birth of such a black hole in a major first. This is huge for the scientific community worldwide as it directly links the death of a star to the formation of a black hole-like compact object.

“Our research is like solving a puzzle by gathering all possible evidence,” Ping Chen, a researcher at the Weizmann Institute of Science in Israel, and lead author of a study published in Nature, was quoted as saying by Cosomos Magazine.

It started with the discovery of a super bright object in space, called SN 2022jli. The object, located some 76 million years away, was discovered by a South African amateur astronomer, Berto Monard. Soon it was confirmed that they had their eyes set on a supernova. A supernova occurs just as a star is breathing its last, or when a black hole is about to form.

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Over ten years ago, the Dark Energy Survey (DES) began mapping the Universe to find evidence that could help us understand the nature of the mysterious phenomenon known as dark energy.

I’m one of more than 100 contributing scientists that have helped produce the final DES measurement, which has just been released at the 243rd American Astronomical Society meeting in New Orleans.

Dark energy is estimated to make up nearly 70 percent of the observable Universe, yet we still don’t understand what it is. While its nature remains mysterious, the impact of dark energy is felt on grand scales. Its primary effect is to drive the accelerating expansion of the Universe.

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HELSINKI — China launched its Einstein Probe early Tuesday to detect X-ray emissions from violent, fleeting cosmic phenomena using novel lobster eye-inspired optics.

A Long March 2C rocket lifted off from Xichang Satellite Launch Center in southwestern China at 2:03 a.m. (0703 UTC), Jan. 9. The China Aerospace Science and Technology Corp. (CASC) confirmed launch success within the hour.

The Einstein Probe (EP) is part of growing Chinese strategic space science efforts. The spacecraft will spend at least three years observing distant, violent interactions such as tidal disruption events—in which stars are pulled apart by supermassive black holes—supernovae, and detect and localize the high-energy, electromagnetic counterparts to gravitational wave events.

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Nube is an almost invisible dwarf galaxy discovered by an international research team led by the Instituto de Astrofísica de Canarias (IAC) in collaboration with the University of La Laguna (ULL) and other institutions.

The name was suggested by the 5-year-old daughter of one of the researchers in the group and is due to the diffuse appearance of the object. Its surface brightness is to faint that it had passed unnoticed in the various previous surveys of this part of the sky due to the object’s diffuse appearance as if it were some kind of ghost. This is because its stars are so spread out in such a large volume that “Nube” (Spanish for “Cloud”) was almost undetectable.

This newly discovered galaxy has a set of specific properties which distinguish it from previously known objects. The research team estimate that Nube is a 10 times fainter than others of its type, but also 10 times more extended than other objects with a comparable number of stars.

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Using a spectral synthesis code designed to simulate conditions in interstellar matter, astronomers have explored a faint tidal disruption event (TDE) designated iPTF16fnl. Results of the study, published Dec. 29 on the pre-print server arXiv, deliver important insights into the properties of this TDE.

TDEs are astronomical phenomena that occur when a star passes close enough to a and is pulled apart by the black hole’s tidal forces, causing the process of disruption. Such tidally-disrupted stellar debris starts raining down on the black hole and radiation emerges from the innermost region of accreting debris, which is an indicator of the presence of a TDE. All in all, the debris stream-stream collision causes an energy dissipation, which may lead to the formation of an accretion disk.

Therefore, TDEs are perceived by as potentially important probes of strong gravity and accretion physics, providing answers about the formation and evolution of supermassive .

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Thanks to the LIGO and Virgo detectors, researchers now regularly observe ripples in spacetime known as gravitational waves, which are caused by catastrophic cosmic events such as black-hole mergers, star explosions, or the big bang itself.

Gravitational waves are ripples in the fabric of spacetime that travel at the speed of light. These are produced in some of the most violent events in the universe, such as black-hole mergers, supernovae, or the Big Bang itself. Since their first detection in 2015, and after three observing runs, the Advanced LIGO and Virgo detectors have detected around 100 such waves.

Thanks to these observations, we are starting to unveil the black-hole population of our universe, study gravity in its most extreme regime and even determine the formation of elements like gold or platinum during the merger of neutron stars.

The LIGO and Virgo detectors are nothing but the most precise rulers ever built by humankind, able to measure the subtle squeezing and stretching of spacetime produced by gravitational waves.

Continue reading “Scientists flip around gravitational-wave data analysis: Have LIGO and Virgo detected a merger of dark-matter stars?” | >

Over the past few decades, it has become quite obvious that humans are not the only living organisms with intelligence.

The story of intelligence you are about to experience goes back 13.8 billion years, back to the moment the universe was born: the Big Bang. It’s a story of time and space, matter and energy. It is a story of unfolding, It’s the story of how the very nature of the physical universe from its very inception led to the universe getting to know itself and eventually, to reflect.

Complexity, Evolution, and Intelligence is comprised of five parts, each corresponding to a movement in Dan Forrest’s “Requiem For The Living.” This composition was performed August 2, 2013 in Raleigh, NC by Bel Canto, conducted by Dr. Bill Young.

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