Search Publications
The broken-exponential radial structure and larger size of the Milky Way galaxy
Imig, Julie; Chen, Bingqiu; Wang, Tao +4 more
The radial structure of a galaxy is a fundamental property that reflects its growth and assembly history. Although it is straightforward to measure that of external galaxies, it is challenging for the Milky Way because of our inside perspective. Traditionally, the radial structure of the Milky Way has been assumed to be characterized by a single-e…
An abrupt change in the stellar spin-down law at the fully convective boundary
Angus, Ruth; Amard, Louis; See, Victor +2 more
Unlike partially convective stars such as the Sun, fully convective stars do not possess a radiative core. Whether a star needs this core to generate a solar-like magnetic dynamo is still unclear. Recent studies suggest fully and partially convective stars exhibit very similar period-activity relationships, hinting that dynamos generated by stars …
A departure from the mass-metallicity relation in merging galaxies due to an infall of metal-poor gas
Pérez-Díaz, Borja; Pérez-Montero, Enrique; Fernández-Ontiveros, Juan A. +2 more
Heavy element accumulation and stellar mass assembly are fundamental processes in the formation and evolution of galaxies. However, the key elements that govern them, such as gas accretion and outflow, are not fully understood. This is especially true for luminous and massive galaxies, which usually suffer strong feedback as massive outflows and l…
The metal-poor atmosphere of a potential sub-Neptune progenitor
Fortney, Jonathan J.; Désert, Jean-Michel; Petigura, Erik A. +12 more
Young transiting exoplanets offer a unique opportunity to characterize the atmospheres of freshly formed and evolving planets. We present the transmission spectrum of V1298 Tau b, a 23-Myr-old warm Jupiter-sized (0.91 ± 0.05 RJ, where RJ is the radius of Jupiter) planet orbiting a pre-main-sequence star. We detect a mostly cl…
Enrichment by extragalactic first stars in the Large Magellanic Cloud
Li, Ting S.; Frebel, Anna; Simon, Joshua D. +8 more
The Large Magellanic Cloud (LMC) is the Milky Way's most massive satellite galaxy, which only recently (~2 billion years ago) fell into our Galaxy. As stellar atmospheres preserve the composition of their natal cloud, the LMC's recent infall makes its most ancient, metal-deficient (`low-metallicity') stars unique windows into early star formation …
Multi-source connectivity as the driver of solar wind variability in the heliosphere
D'Amicis, Raffaella; Long, David M.; Schühle, Udo +18 more
The ambient solar wind that fills the heliosphere originates from multiple sources in the solar corona and is highly structured. It is often described as high-speed, relatively homogeneous, plasma streams from coronal holes and slow-speed, highly variable, streams whose source regions are under debate. A key goal of ESA/NASA's Solar Orbiter missio…
Insights into star formation and dispersal from the synchronization of stellar clocks
Alves, João; Barrado, David; Burkert, Andreas +3 more
Age is one of the most fundamental parameters of a star, yet it is one of the hardest to determine as it requires modelling various aspects of stellar formation and evolution. When we compare the ages derived from isochronal and dynamical traceback methods for six young stellar associations, we find a systematic discrepancy. Specifically, dynamica…
A seven-Earth-radius helium-burning star inside a 20.5-min detached binary
Filippenko, Alexei V.; Han, Zhanwen; Chen, Xuefei +28 more
Binary evolution theory predicts that the second common envelope ejection can produce low-mass (0.32-0.36 M⊙) subdwarf B (sdB) stars inside ultrashort-orbital-period binary systems, as their helium cores are ignited under nondegenerate conditions. With the orbital decay driven by gravitational-wave (GW) radiation, the minimum orbital pe…
Constraints on the dense matter equation of state from young and cold isolated neutron stars
Rea, N.; Marino, A.; Pons, J. A. +3 more
Neutron stars are the dense and highly magnetic relics of supernova explosions of massive stars. The quest to constrain the equation of state (EOS) of ultradense matter and thereby probe the behaviour of matter inside neutron stars is one of the core goals of modern physics and astrophysics. A promising method involves investigating the long-term …
Chemical tracers of a highly eccentric AGB-main-sequence star binary
Menten, K. M.; Pinte, C.; Sahai, R. +32 more
Binary interactions have been proposed to explain a variety of circumstellar structures seen around evolved stars, including asymptotic giant branch (AGB) stars and planetary nebulae. Studies resolving the circumstellar envelopes of AGB stars have revealed spirals, disks and bipolar outflows, with shaping attributed to interactions with a companio…