Search Publications
Evidence of a dynamically evolving Galactic warp
Bailer-Jones, C. A. L.; Fouesneau, M.; Andrae, R. +5 more
In a cosmological setting, the disk of a galaxy is expected to continuously experience gravitational torques and perturbations from a variety of sources, which can cause the disk to wobble, flare and warp1,2. Specifically, the study of galactic warps and their dynamic nature could reveal key information on the formation history of galax…
An ultrahot Neptune in the Neptune desert
Jackman, James A. G.; Bieryla, Allyson; Latham, David W. +81 more
About 1 out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultrashort-period planet1,2. All of the previously known ultrashort-period planets are either hot Jupiters, with sizes above 10 Earth radii (R⊕), or apparently rocky planets smaller than 2 R⊕. Such lack of planets of inte…
Age dating of an early Milky Way merger via asteroseismology of the naked-eye star ν Indi
Smalley, Barry; Chaplin, William J.; Davies, Guy R. +82 more
Over the course of its history, the Milky Way has ingested multiple smaller satellite galaxies1. Although these accreted stellar populations can be forensically identified as kinematically distinct structures within the Galaxy, it is difficult in general to date precisely the age at which any one merger occurred. Recent results have rev…
Carbon star formation as seen through the non-monotonic initial-final mass relation
Ramirez-Ruiz, Enrico; Girardi, Léo; Cheng, Sihao +13 more
The initial-final mass relation (IFMR) links the birth mass of a star to the mass of the compact remnant left at its death. While the relevance of the IFMR across astrophysics is universally acknowledged, not all of its fine details have yet been resolved. A new analysis of a few carbon-oxygen white dwarfs in old open clusters of the Milky Way led…
Infrared detection of aliphatic organics on a cometary nucleus
Bellucci, G.; Carlson, R. W.; Fornasier, S. +28 more
The European Space Agency's Rosetta mission1 has acquired unprecedented measurements of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko (hereafter, 67P), the composition of which, as determined by in situ and remote-sensing instruments, including the VIRTIS instrument2, seems to be an assemblage of ices, mineral…
A disk-dominated and clumpy circumgalactic medium of the Milky Way seen in X-ray emission
Kaaret, P.; Kuntz, K. D.; Koutroumpa, D. +7 more
The Milky Way galaxy is surrounded by a circumgalactic medium1 that may play a key role in galaxy evolution as the source of gas for star formation and a repository of metals and energy produced by star formation and nuclear activity2. The circumgalactic medium may also be a repository for baryons seen in the early universe, …
An extremely energetic supernova from a very massive star in a dense medium
Bieryla, Allyson; Laher, Russ R.; Masci, Frank J. +14 more
The interaction of a supernova with a circumstellar medium (CSM) can dramatically increase the emitted luminosity by converting kinetic energy to thermal energy. In `superluminous' supernovae of type IIn—named for narrow hydrogen lines1 in their spectra—the integrated emission can reach2-6 ~1051 erg, attainable by …
A global geomorphologic map of Saturn's moon Titan
Williams, D. A.; Hayes, A. G.; Wall, S. D. +10 more
Titan has an active methane-based hydrologic cycle1 that has shaped a complex geologic landscape2, making its surface one of most geologically diverse in the Solar System. Despite the differences in materials, temperatures and gravity fields between Earth and Titan, many of their surface features are similar and can be interp…
An ultra-massive white dwarf with a mixed hydrogen-carbon atmosphere as a likely merger remnant
Gänsicke, B. T.; Dhillon, V. S.; Tremblay, P. -E. +11 more
White dwarfs are dense, cooling stellar embers consisting mostly of carbon and oxygen1, or oxygen and neon (with a few per cent carbon) at higher initial stellar masses2. These stellar cores are enveloped by a shell of helium, which in turn, is usually surrounded by a layer of hydrogen, generally prohibiting direct observatio…
AstroSat detection of Lyman continuum emission from a z = 1.42 galaxy
Verhamme, Anne; Inoue, Akio K.; Schaerer, Daniel +10 more
One of the outstanding problems of current observational cosmology is to understand the nature of sources that produced the bulk of the ionizing radiation after the Cosmic Dark Age. Direct detection of these reionization sources1 is practically infeasible at high redshift (z) due to the steep decline of intergalactic medium transmission…