Simulations cast doubt on unusual asteroid’s ‘dark comet’ status

In 2031, Japan’s Hayabusa2 spacecraft will arrive at the near-Earth asteroid 1998 KY26: a tiny body that is accelerating in a way that astronomers have struggled to explain. Some studies have suggested that the asteroid is pushed along by water escaping from it as gas, making it an as-yet theoretical “dark comet.”

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World’s most sensitive lab-based axion search presents its first results

Physicists at the ALPS II collaboration have reported the first results from the Any-Light-Particle-Search (ALPS) II experiment: the most sensitive instrument of its kind in the search for hypothetical “axions.” Headed by Axel Lindner at the DESY Research Centre in Germany, the collaboration found no evidence for axions in this initial campaign, but its results offer valuable guidance for future runs: tightening the search for one of the most promising candidates for dark matter.

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Supreme Court weighs limits on lawsuits against federal law enforcement officers

Justices are revisiting a 1971 ruling that established a limited pathway for individuals to seek damages from federal agents who violate constitutional protections

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Quantum could solve AI energy drain, says tech founder

Quantum computers could curb the vast energy demands of artificial intelligence data centers with their ability to run complex calculations, one of the tech’s pioneers told AFP.

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Light-pulse pairs reveal the femtosecond decay of an inner-shell hole in xenon atoms

Researchers at the UVSOR Synchrotron Facility (Institute for Molecular Science, Japan) and partner institutions have observed the decay of a xenon 4d core hole, an inner-shell vacancy, directly in the time domain. They used pairs of phase-coherent extreme ultraviolet pulses from a synchrotron to make the photoelectron wave packets they released interfere. The contrast of the interference fringes decreased over a few femtoseconds as the delay between the pulses increased. A model using literature core-hole lifetimes of about 6 femtoseconds reproduced this rapid decay of the fringe contrast. The study is published in the journal Physical Review A.

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Barium titanate’s optical properties emerge more clearly after decades of widely varying measurements

A KAIST-led research team has characterized how light propagates through and is absorbed by barium titanate (BTO), a promising material for next-generation optical communication devices. By clarifying optical properties that had been difficult to determine because of the material’s complex internal structure, the study provides a foundation for designing these devices.

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The ELT can probe ultra-diffuse galaxies and their dark matter mysteries

We’ve been waiting a long time for the Extremely Large Telescope’s first light, scheduled for March 2029. Telescopes this large, powerful and costly always have multiple science goals, and that’s true for the ELT. One of its science goals is to study fundamental aspects of the universe, including dark matter.

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A stellar odd couple at an unusual stage of evolution

Most of the stars in the Milky Way are what we might call normal stars. They’re main sequence stars like our sun, meaning they’re doing what most people probably think stars do: shining as they fuse hydrogen atoms into helium atoms on a vast scale.

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Subaru Telescope reveals the shape and temperature of Comet Encke’s nucleus

Mid-infrared observations with the Subaru Telescope have revealed the shape and surface temperature of the nucleus of Comet 2P/Encke. By analyzing how the nucleus’s thermal emission changed as it rotated, the researchers found that the nucleus is elongated, with a long axis of about 7 kilometers and a short axis of about 3 kilometers. They also determined that the surface temperature at the time of observation was 328 ± 7 Kelvin (about 55°C).

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Upgraded microscope can now watch individual quantum particles in motion

Energy can be carried in a number of ways: by electrons, the particles that underpin all modern electronics, as well as by quasiparticles, the results of different particles interacting with one another at the quantum level. Columbia chemist Milan Delor has been watching these different forms of energy flow with an instrument called stroboSCAT, a unique microscope that uses strobe-like light pulses to capture particles and quasiparticles as they move through different materials.

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New perovskite system extends room-temperature spin polarization via successive quantum wells

A research team led by Lu Haipeng, a professor in the Department of Chemistry at The Hong Kong University of Science and Technology (HKUST), has achieved a breakthrough in preserving spin information for optoelectronic technologies. The team has developed a perovskite chiral multiple quantum-well system that maintains spin polarization approximately 300 times longer at room temperature. The study opens new possibilities for future quantum technologies and next-generation spin-based applications. The study was published in the journal Nature Photonics.

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Light reflecting within thin films can masquerade as molecular signals in perovskite solar materials

An infrared signal thought to reveal how molecules in perovskite solar materials respond to light-generated charges can arise largely from the way light travels through the thin film itself, a new theoretical study shows. Jun Nishida, assistant professor at the Institute for Molecular Science (IMS), Japan, found that light-generated charges alter how infrared light is reflected and transmitted within the film layers, producing sharp features that resemble changes in molecular vibrations even when the vibrations themselves are unaltered.

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The supernova impostor: Chandra finds likely source of giant star’s repeated outbursts

Using NASA’s Chandra X-ray Observatory, astronomers have discovered what is triggering repeated outbursts from a giant, unstable star.

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First known ‘disappearing planet’ has a neighbor that makes it wobble like a top

UCLA-led astronomers have discovered the first known “disappearing planet” about 1,000 light-years away. The planet, TOI-2535 b, is a “hot Jupiter,” a gas giant that orbits extremely close to its host star. TOI-2535 b whips around its star in only 8.25 days—10 times faster than the 88 days that Mercury takes to go around our sun once.

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Our sun’s undiscovered stellar nemesis is still out there, says physicist

Long-period, high-inclination comets of the sort that can cause extinction-level impacts here on Earth have long been thought to originate from a theoretical Oort cloud. That is, a roughly spherical cloud of icy cometary objects that number in the trillions at distances that extend up to 1.6 light-years away.

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