Articles in 2022

Using detailed solar coronal observations and advanced magnetohydrodynamics simulations, the authors find that a coronal web above a region of coronal holes and active regions dynamically evolves and persistently drives the highly structured slow solar wind.

Exoplanets with radii between 1.4 and 2.5 R_⊕ may have atmospheres strongly enhanced in helium after a few billion years, due to the preferential loss of hydrogen over helium via photoevaporation. If observed, this phenomenon could demonstrate the importance of photoevaporation in shaping the radius valley.

Observational evidence from planetary systems around white dwarfs shows that planetesimal formation occurs during the first few hundred thousand years after cloud collapse. Iron accreted by these white dwarfs must have been formed by short-lived radioactive nuclides driving iron core formation in planetesimals that form together with the parent star.

Solar wind observations from the Magnetospheric Multiscale mission reveal bursty, turbulent properties within a reconnection diffusion region, in contrast with the usual quasi-steady state of solar wind reconnection. Between October 2017 and May 2019 75 other similar events were identified, indicating the relevance of turbulent reconnection in the solar wind.

The rapid rise in brightness of a tidal disruption event is attributed to the destruction of a main sequence star by a black hole of intermediate mass in a dwarf galaxy. Such events are rare, and non-accreting intermediate-mass black holes are challenging to find.

Spectroscopic and photometric analyses show the B-type-star γ Columbae to be the exposed stellar core of a massive progenitor star that has just finished central hydrogen fusion.

A method that uses intersource correlograms measured by a single-station seismograph to constrain planetary interiors is presented. Applied to Mars, it measures a core radius of 1,812 ± 20 km, consistent with InSight direct-seismic-wave measurements. Such a method is useful in planetary exploration where the deployment of a full network of seismographs is unlikely.

The marsquakes dataset acquired by InSight shows that the Cerberus Fossae graben system is still actively opening, accounting for almost half of Mars’s seismic moment detected so far. This activity indicates the presence of a warm source located at 40 km depth, possibly due to local magmatic processes.

A simultaneous reconstruction of three functions describing the expansion of the Universe and gravitational effects on light and matter shows the extent to which modified gravity can address tensions between the standard cosmological model and a large body of observations.

X-ray polarimetry observations with the Imaging X-ray Polarimetry Explorer constrain the accretion geometry in an X-ray pulsar and provide evidence for a misalignment of the spin, magnetic and orbital axes in Her X-1.

Using Gaia and XMM-Newton to constrain the distance to and properties of the central compact object of a supernova remnant, an extremely light (\(0.7{7}_{-0.17}^{+0.20}\) solar masses) neutron star has been found. This mass is twice as light as normally found for these kinds of object, and places limits on the allowed equations of state of neutron star matter.

A convolutional neural network trained with mock galaxy cluster maps is applied to real maps from the Planck satellite, successfully predicting the masses of over 1,000 observed clusters and finding a 15% bias in masses measured directly from Planck.

The residual magnetic field detected in some carbonaceous chondrite meteorites is a remanent of the primordial field of the early solar nebula, preserved via aqueous alteration processes that happened in large planetesimals formed around 4 Myr after CAI formation and just before the dissipation of the solar nebula.

JWST observations reveal more than 17 nested dust shells that formed in the colliding winds of the massive binary WR 140 that enrich the surrounding interstellar medium with organic compounds and carbon-rich dust.

Energetic neutral atom fluxes measured at 1 au by the IBEX spacecraft between 2014 and 2019 are used as proxy to map the heliosphere at high resolution. Persistent ripples that corrugate the heliospheric boundary and induce variations by up to ~10 au are observed, with marked north–south asymmetry.

Blue large-amplitude pulsators (BLAPs) represent a mysterious class of hot stars pulsating in an unexpectedly extreme way. Here we report the discovery of an unusual BLAP at a short-lived phase that provides a new path to understand their physical origins.

Multiple gas disks, both misaligned with the stellar disk, are reported in two galaxies, providing evidence for multiple gas acquisition events, challenging the traditional picture of galaxy accretion and suggesting a new trigger mechanism for star formation.

Earth-mass planets in the classical habitable zone of M dwarfs span a range of water content higher than previously computed, according to a planetary population model that includes the effects of water enrichment in the primordial atmosphere.

Spectropolarimetric observations of three tidal disruption events reveal that they are optically polarized at the 1–2% level by a cloud of electrons surrounding the black hole (in good agreement with theory).

A neutron star candidate in a close binary has been discovered using a radial velocity method and characterized with a variety of ground- and space-based telescopes. The system probably represents an underexplored population of non-accreting and/or non-beaming neutron stars.