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New telescope images uncover ‘Green Monster’ in Cassiopeia A Using NASA’s James Webb Space Telescope, astronomers uncovered a mysterious feature within the remnant, nicknamed the “Green Monster,” alongside a puzzling network of ejecta filaments forming a web of oxygen-rich material. When combined with X-rays from NASA’s Chandra X-ray Observatory, the data helped astronomers shed light on the origin of the Green Monster and revealed new insights into the explosion that created Cas A about 340 years ago, from Earth’s perspective. phys.org Go to SourceRead More →

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Astronomers explore the nature of the nearest tidal disruption event Using the Neutron star Interior Composition Explorer (NICER) onboard the International Space Station (ISS), astronomers have observed IGR J12580+0134, which is the closest tidal disruption event. Results of the observational campaign, presented April 17 on the preprint server arXiv, shed more light on the nature and behavior of this event. phys.org Go to SourceRead More →

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The universe’s brightest lights have some dark origins Did you know some of the brightest sources of light in the sky come from the regions around black holes in the centers of galaxies? It sounds a little contradictory, but it’s true. They may not look bright to our eyes, but satellites have spotted oodles of them across the universe. phys.org Go to SourceRead More →

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Harnessing Nanosatellite Technology for Lunar Infrastructure How can nanosatellites help advance lunar exploration and settlement? This is what a recent study presented at the 56th Lunar and Planetary Science Conference hopes to address as a team of researchers from Grahaa Space in India investigated the pros, cons, and applications for using nanosatellites on the Moon. This study has the potential to help scientists, engineers, mission planners, and future lunar astronauts develop and test new technologies for advancing lunar exploration, and possibly beyond the Moon. Universe Today Go to SourceRead More →

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Flexible Launch Opportunities for the Uranus Flagship Mission What methods can be employed to send a spacecraft to Uranus despite the former’s immense distance from Earth? This is what a recent study presented at the 56th Lunar and Planetary Science Conference hopes to address as a team of scientists investigated ways to cut the travel time to the second most distant planet from the Sun. This study has the potential to help scientists, engineers, and mission planners develop low-cost and novel techniques for deep space travel while conducting cutting-edge science. Universe Today Go to SourceRead More →

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Plausible Indication of Gamma-Ray Absorption by Dark Matter in NGC 1068 Gonzalo Herrera arXiv:2504.21560v1 Announce Type: cross Abstract: NGC 1068 is the brightest extragalactic source in high-energy neutrinos as seen by IceCube, yet the accompanying gamma-ray flux is orders of magnitude weaker. It has been argued that this indicates that the bulk of neutrinos and gamma rays are emitted in the innermost vicinity of the central supermassive black hole, which is transparent to neutrinos, but opaque to gamma rays. Even in such extreme scenarios for the acceleration of cosmic rays, astrophysical models typically overestimate the low-energy gamma-ray flux and/or require some fine-tuning in the physicalRead More →

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Effective Field Theories in Magnetohydrodynamics Amir Jafari arXiv:2504.10763v2 Announce Type: replace-cross Abstract: We briefly review the recent developments in magnetohydrodynamics, which in particular deal with the evolution of magnetic fields in turbulent plasmas. We especially emphasize (i) the necessity of renormalizing equations of motion in turbulence where velocity and magnetic fields become H”older singular; (ii) the breakdown of Laplacian determinism (spontaneous stochasticity) for turbulent magnetic fields; and (iii) the possibility of eliminating the notion of magnetic field lines, using instead magnetic path lines as trajectories of Alfvenic wave-packets. These methodologies are then exemplified with their application to the problem of magnetic reconnection — rapid changeRead More →

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An improved parametrized test of general relativity using the IMRPhenomX waveform family: Including higher harmonics and precession Soumen Roy, Maria Haney, Geraint Pratten, Peter T. H. Pang, Chris Van Den Broeck arXiv:2504.21147v1 Announce Type: cross Abstract: When testing general relativity (GR) with gravitational wave observations, parametrized tests of deviations from the expected strong-field source dynamics are one of the most widely used techniques. We present an updated version of the parametrized framework with the state-of-art IMRPhenomX waveform family. Our new framework incorporates deviations in the dominant mode as well as in the higher-order modes of the waveform. We demonstrate that the missing physics of eitherRead More →

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Keplerian motion of a compact source orbiting the inner disc of PDS 70: a third protoplanet in resonance with b and c? Iain Hammond, Valentin Christiaens, Daniel J. Price, Dori Blakely, David Trevascus, Markus J. Bonse, Faustine Cantalloube, Gabriel-Dominique Marleau, Christophe Pinte, Sandrine Juillard, Matthias Samland, William Thompson, Alex Wallace arXiv:2504.11127v2 Announce Type: replace Abstract: The disc around PDS 70 hosts two directly imaged protoplanets in a gap. Previous VLT/SPHERE and recent James Webb Space Telescope/NIRCam observations have hinted at the presence of a third compact source in the same gap at ~13 au, interior to the orbit of PDS 70 b. We reduce sevenRead More →

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Circularly Polarized Gravitational Wave Background Search with a Network of Space-borne Triangular Detectors Ju Chen, Chang Liu, Yun-Long Zhang arXiv:2410.18916v2 Announce Type: replace-cross Abstract: Circularly polarized gravitational wave backgrounds are predicted in many well-motivated models of inflation and phase transitions involving spontaneous parity violation. In this work, we investigate the detection of such parity-violating signals with the network of two space-borne triangular detectors. We derive the general analytical formula for the overlap reduction functions of networks composed of two triangular detectors, by exploiting the system’s symmetrical properties under the long-wave approximation. Based on these results, we further assess the detectability of a parity-violating background withRead More →

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Exploring Valles Marineris on Mars with Helicopters, Not Rovers What are the best methods to explore Valles Marineris on Mars, which is the largest canyon in the solar system? This is what a recent study presented at the 56th Lunar and Planetary Science Conference hopes to address as a team of researchers investigated how helicopters could be used to explore Valles Marineris, which could offer insights into Mars’ chaotic past. This study has the potential to help scientists and engineers develop new methods for studying Mars’s history and whether the Red Planet once had life as we know it. Universe Today Go to SourceRead More →