Articles

A hypermodel approach is used to analyse gravitational-wave signals under multiple models simultaneously, enabling the data-driven study of systematic modelling errors. The authors verify the approach on existing observations of the two observed binary neutron star merger signals GW170817 and GW190425 and a third candidate event.

Harnessing the resolving power of space very long baseline interferometry results in a link between 22 GHz H₂O MegaMaser emission and accretion activity in the thin disc around the nucleus of galaxy NGC 4258. The emission regions appear consistent with a periodic magneto-rotational instability in the disc.

Big-data labelling is critical to harness the power of supervised machine learning in astronomy. Neural networks applied to the solar flux emergence problem considerably reduce the manual labelling burden and easily extract higher-level information.

Modelling of Earth- or super-Earth-sized planets with a thick H–He atmosphere shows that the hydrogen collision-induced absorptions in the infrared wavelength can make the planet amenable to hosting surface liquid water for several billion years, thus creating a long-term potentially habitable environment.

Quasars have been proposed as one of the major sources of ionizing photons during the epoch of reionization. New photometric analysis of high-redshift, low-luminosity quasars provides a firm constraint and shows that quasars can provide fewer than 7% of the photons required.

Simulations based on observations of galaxies in the COSMOS field at a redshift of 2 can be wound back to the early Universe, and wound forward to the present day to predict the fate of detected galaxy protoclusters, including the well-studied Hyperion protocluster.

Using the MeerKAT radio telescope, the authors have discovered a neutron star with an ultra-long spin period of 76 s. Though it resides in the neutron star graveyard, it emits radio waves and challenges our understanding of neutron star evolution.

A massive and expansive Keplerian disk surrounding a massive O star in the Galaxy’s Central Molecular Zone is gravitationally stable. The disk features two embedded spirals, probably generated by external perturbations from a nearby gas condensation.

New measurements of the metallicities of ultraluminous infrared galaxies show that observations of underabundances of metals in these galaxies are most probably due to heavy dust obscuration, rather than intrinsic metal-poor gas accretion.

The inclusion of magnetohydrodynamic instabilities in the transport of both angular momentum and material within the Sun can simultaneously explain the internal rotation regime of the Sun, its surficial lithium abundance and the helium abundance in the envelope, which were inconsistent with the predictions of previous standard solar models.

Impact-related cooling of asteroids happened between 7.8 and 11.7 million years after Solar System formation due to dynamical forcing following the gas disk dissipation, an early giant planet instability, or a combination of the two.

A high-resolution three-dimensional global climate model of Saturn captures the small-scale dynamics of its stratosphere. It is able to reproduce the observed semi-annual equatorial oscillation and finds evidence of an interhemispheric meridional circulation that can explain the periodicity of its equatorial oscillation and the seasonal behaviour of hydrocarbon abundances.

TOI-500 hosts at least four planets, the innermost of which is an Earth-sized ultra-short-period body with a density similar to Earth. The architecture of the TOI-500 system can be explained by a slow, secular, low-eccentricity migration scenario.

A laboratory analysis of track-rich interplanetary dust grains collected from our stratosphere reveals their origin in the distant Kuiper belt, which allows researchers to probe the chemical properties of Kuiper belt objects and our debris disk.

Images from the Subaru Telescope and the Hubble Space Telescope reveal an embedded protoplanet at a wide separation around the star AB Aurigae. The system provides evidence for a long-considered alternative mechanism for forming Jupiter-like planets.

The helicity barrier mechanism causes transfer of Alfvénic turbulent energy into ion-cyclotron waves in the solar atmosphere, playing a key role in solar-wind heating and in generating the observed differences between slow and fast solar wind.

The discovery of high-frequency inertial waves in the near-surface layers of the Sun—travelling much faster than hydrodynamics alone would allow—points to hidden dynamics of unknown nature below the surface of the Sun.

Astronomical research facilities, such as space telescopes, space probes or ground-based observatories, are the largest contributor to an astronomer’s carbon footprint, well beyond other activities such as flying to conferences or running computer simulations.

Fragment #443 of the Luna 16 sample is of extra-lunar origin. It was probably delivered from an LL chondrite asteroid around 1 Gyr ago, directly as a micrometeorite or as a result of a bigger impact, and never experienced temperatures higher than 400 °C since its formation. Its characteristics are compatible with a stony parent body coming from the Flora family.

An axion cloud surrounding a spinning black hole would rotate the electric vector position angles of linearly polarized emissions. Tight constraints on the axion–photon coupling can therefore be obtained from polarization information in the Event Horizon Telescope’s images of M87^⋆.