Volume 7 Issue 9, September 2023

A distant type Ia supernova that was significantly magnified by a tiny foreground galaxy may imply a large population of small compact galaxies.

Observations using JWST show water, probably from a subsurface ocean on Saturn’s icy moon, spewing into a large plume that extends far beyond the moon’s surface. This continuous outgassing results in a torus of water along Enceladus’s orbit and is so intense that the plume is the prime source of water across the Saturnian system.

The 21-cm absorption lines from neutral hydrogen at cosmic dawn are proposed as a probe to simultaneously study dark matter particle mass and cosmic heating history. By applying a statistical approach to simulated data this probe is shown to distinguish the effects of dark matter from those of cosmic heating.

A dedicated method for analysing moderately saturated measurements from Swift’s Ultraviolet and Optical Telescope is used to perform a time-resolved analysis for the initial white filter exposure of GRB 220101A. This analysis reveals a rapidly evolving ultraviolet and optical flare, distinguished by extremely high luminosity and unexpected temporal behaviour.

Cosmological surveys aim to constrain the ‘gravitational slip’, a key signature of modified gravity — but an as-yet unknown force acting on dark matter could mimic the gravitational slip and invalidate the test. By additionally factoring in a measurement of gravitational redshift, future surveys could have the power to distinguish between these possibilities.

Measurements of the redshifted 21 cm line of neutral hydrogen could be a powerful tool for precision cosmology, constraining fundamental parameters and probing the cosmological dark ages. However, practical challenges must first be addressed.

An ethical approach to research in extreme environments can lay the foundations for future space exploration that respects ecologies, is founded on authentic partnerships and supports co-learning from diverse communities of non-scientists.

The Zhurong rover measured in situ the Martian magnetic field vector at 16 sites. An average horizontal intensity of 11.2 ± 10.9 nT is recorded, substantially lower than the ~80 nT measured from orbit. Demagnetization over the entire Utopia Basin or at small scales around the Zhurong site might explain this difference.

Trace gases CO and HCN are detected by ALMA in various locations of Jupiter’s disc. Contrary to CO, HCN is depleted in the auroral regions, indicative of the action of heterogeneous chemistry that bonds HCN to organic aerosol particles produced in the aurorae.

The extensive water plume that originates from Enceladus and extends up to 40 Enceladus radii is mapped and characterized by JWST. Data suggest a sustained and uninterrupted plume activity spanning decades and a surface dominated by crystalline H₂O ice. No other molecules were detected in gaseous form.

The presence of NaCl crystals within the sample gathered from S-type asteroid Itokawa and genetically linked to the surrounding plagioclase indicates the presence of an active hydrothermal system within Itokawa, contrary to the assumption that parent asteroids of ordinary chondrites were relatively water-depleted.

A high-resolution global climate simulation of tidally locked rocky planets orbiting around M dwarfs with explicit convection resolves the behaviour of their clouds, determining the cloud properties and suggesting the frequent appearance of cloud streets affecting the planetary energy balance.

Analysis of a large sample of double-mode RR Lyrae stars shows that they are robust distance and metallicity indicators. Considering that the number of double-mode RR Lyr stars is comparable with that of classical Cepheids, they would be excellent distance tracers for older objects in the near-field universe.

Using the POSYDON population synthesis code, this study predicts the existence of massive, thirty-solar-mass black-hole binaries in Milky-Way-like galaxies, challenging previous theories.

SN 2022qmx, dubbed SN Zwicky, is a rare, gravitationally lensed type Ia supernova, magnified by a factor of 25, discovered by the Zwicky Transient Facility. Follow-up Keck observations reveal four multiple images with unusually small separation.

Gamma-ray burst 220101A reached an absolute magnitude of −39.4. Using a new method to analyse saturated Swift/UVOT data, Jin et al. uncover the shock activity that led to a bright optical–UV flare from this event.

The 21-cm absorption lines from atomic hydrogen, known as the 21-cm forest, are here proposed to probe simultaneously dark matter particle mass and cosmic heating history. With upcoming observational facilities, the statistical features of the 21-cm forest will constrain the nature of dark matter and the first galaxies at cosmic dawn.

Our current cosmological observations cannot distinguish between a cosmological model with a fifth force acting on dark matter and one for which the laws of gravity are modified. Instead, a method using future gravitational redshift data is proposed.

James Stone started developing Athena in the mid-2000s, building on several years’ work on numerical methods for compressible magnetohydrodynamics in shocks. A couple of incarnations later, AthenaK is ready to face the exascale computing future.

The BOOTES global network of robotic telescopes is constantly watching the sky for astronomical transients, from its seven locations spread across both hemispheres.