Search Publications
Dynamics of young stellar clusters as planet-forming environments
Parker, Richard J.; Reiter, Megan
Most stars and thus most planetary systems do not form in isolation. The larger star-forming environment affects protoplanetary disks in multiple ways: Gravitational interactions with other stars truncate disks and alter the architectures of exoplanet systems; external irradiation from nearby high-mass stars truncates disks and shortens their life…
A possible nearby microlensing stellar remnant hiding in Gaia DR3 astrometry
Rybicki, Krzysztof A.; Wyrzykowski, Łukasz; Kruszyńska, Katarzyna +3 more
Massive galactic lenses with large Einstein Radii should cause a measurable astrometric microlensing effect, that is, a light centroid shift due to the motion of the two images. Such a shift in the position of a background star due to microlensing was not included in the Gaia astrometric model, and therefore significant deviation should cause Gaia…
Testing a scaling relation between coherent radio emission and physical parameters of hot magnetic stars
Wade, Gregg A.; Chandra, Poonam; Das, Barnali +4 more
Coherent radio emission via electron cyclotron maser emission (ECME) from hot magnetic stars was discovered more than two decades ago, but the physical conditions that make the generation of ECME favourable remain uncertain. Only recently was an empirical relation, connecting ECME luminosity with the stellar magnetic field and temperature, propose…
TOI-2119: a transiting brown dwarf orbiting an active M-dwarf from NASA's TESS mission
Latham, David W.; Stassun, Keivan G.; Collins, Karen A. +27 more
We report the discovery of TOI-2119b, a transiting brown dwarf (BD) that orbits and is completely eclipsed by an active M-dwarf star. Using light-curve data from the Transiting Exoplanet Survey Satellite mission and follow-up high-resolution Doppler spectroscopic observations, we find the BD has a radius of Rb = 1.08 ± 0.03RJ…
HD 207897 b: A dense sub-Neptune transiting a nearby and bright K-type star
Bouchy, F.; Deleuil, M.; Moutou, C. +90 more
We present the discovery and characterization of a transiting sub-Neptune that orbits the nearby (28 pc) and bright (V = 8.37) K0V star HD 207897 (TOI-1611) with a 16.20-day period. This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite mission and radial velocity (RV) observations from the SOPHIE, Autom…
Charting galactic accelerations - II. How to 'learn' accelerations in the solar neighbourhood
Evans, N. W.; Naik, A. P.; An, J. +1 more
Gravitational acceleration fields can be deduced from the collisionless Boltzmann equation, once the distribution function is known. This can be constructed via the method of normalizing flows from data sets of the positions and velocities of stars. Here, we consider application of this technique to the solar neighbourhood. We construct mock data …
The BepiColombo Environment Radiation Monitor, BERM
Vainio, Rami; Moissl, Richard; Oleynik, Philipp +9 more
The BepiColombo Environment Radiation Monitor (BERM) on board the European Space Agency's Mercury Planetary Orbiter (MPO), is designed to measure the radiation environment encountered by BepiColombo. The instrument measures electrons with energies from ∼150 keV to ∼10 MeV, protons with energies from ∼1.5 MeV to ∼100 MeV, and heavy ions with Linear…
Four bright eclipsing binaries with γ Doradus pulsating components: CM Lac, MZ Lac, RX Dra, and V2077 Cyg
Van Reeth, Timothy; Southworth, John
The study of pulsating stars in eclipsing binaries holds the promise of combining two different ways of measuring the physical properties of a star to obtain improved constraints on stellar theory. Gravity (g) mode pulsations such as those found in γ Doradus stars can be used to probe rotational profiles, mixing, and magnetic fields. Until recentl…
Probing vainsthein-screening gravity with galaxy clusters using internal kinematics and strong and weak lensing
Umetsu, Keiichi; Pizzuti, Lorenzo; Saltas, Ippocratis D. +1 more
We use high-precision combined strong/weak lensing and kinematics measurements of the total mass profiles of the observed galaxy clusters MACS J1206.2-0847 and Abell S1063, to constrain the relativistic sector of the general DHOST dark energy theories, which exhibit a partial breaking of the so called Vainsthein screening mechanism, on the linear …
Constraints on the Galactic Centre environment from Gaia hypervelocity stars II: The evolved population
Rossi, E. M.; Marchetti, T.; Evans, F. A.
A dynamical encounter between a stellar binary and Sgr A* in the Galactic Centre (GC) can tidally separate the binary and eject one member with a velocity beyond the escape speed of the Milky Way. These hypervelocity stars (HVSs) can offer insight into the stellar populations in the GC environment. In a previous work, our simulations showed that t…