Search Publications
Missions
Journals
Publication Years
Newly Discovered Wolf-Rayet Stars in M31
Massey, Philip; Neugent, Kathryn F.
The evolved massive star populations of the Local Group galaxies are generally thought to be well understood. However, recent work has suggested that the Wolf-Rayet (WR) content of M31 may have been underestimated. We therefore began a pilot project to search for new WRs in M31 and to reexamine the completeness of our previous WR survey, finished …
An inner warp discovered in the disk around HD 110058 using VLT/SPHERE and HST/STIS
Ménard, F.; Milli, J.; Boccaletti, A. +16 more
Context. An edge-on debris disk was detected in 2015 around the young, nearby A0V star HD 110058. The disk showed features resembling those seen in the disk of β Pictoris that could indicate the presence of a perturbing planetary-mass companion in the system.
Aims: We investigated new and archival scattered light images of the disk in order t…
Detecting planetary mass companions near the water frost-line using JWST interferometry
Carter, Aarynn L.; Hinkley, Sasha; Sallum, Steph +4 more
JWST promises to be the most versatile infrared observatory for the next two decades. The Near Infrared and Slitless Spectrograph (NIRISS) instrument, when used in the Aperture Masking Interferometry (AMI) mode, will provide an unparalleled combination of angular resolution and sensitivity compared to any existing observatory at mid-infrared wavel…
Determining satellite infall times using machine learning
Cautun, Marius; Barmentloo, Stan
A key unknown of the Milky Way (MW) satellites is their orbital history, and, in particular, the time they were accreted onto the MW system since it marks the point where they experience a multitude of environmental processes. We present a new methodology for determining infall times, namely using a neural network (NN) algorithm. The NN is trained…
Sulfur abundances in three Galactic clusters: Ruprecht 106, Trumpler 5, and Trumpler 20
Bonifacio, P.; Caffau, E.; Monaco, L. +4 more
Context. Sulfur (S) is one of the lesser-studied α-elements. Published investigations of its behavior have so far focused on local stars, and only a few clusters of the Milky Way have been considered to study this topic. We aim to study the S content of the globular cluster Ruprecht 106 - which has never before been studied for this purpose, but i…
Spectra of V1405 Cas at the Very Beginning Indicate a Low-mass ONeMg White Dwarf Progenitor
Maehara, Hiroyuki; Nogami, Daisaku; Yamanaka, Masayuki +9 more
The lowest possible mass of ONeMg white dwarfs (WDs) has not been clarified despite its importance in the formation and evolution of WDs. We tackle this issue by studying the properties of V1405 Cas (Nova Cassiopeiae 2021), which is an outlier given a combination of its very slow light-curve evolution and the recently reported neon-nova identifica…
The blue supergiant Sher 25 revisited in the Gaia era
Butler, K.; Weßmayer, D.; Przybilla, N. +2 more
Aims: The evolutionary status of the blue supergiant Sher 25 and its membership to the massive cluster NGC 3603 are investigated.
Methods: A hybrid non-local thermodynamic equilibrium (non-LTE) spectrum synthesis approach is employed to analyse a high-resolution optical spectrum of Sher 25 and five similar early B-type comparison stars i…
On the Migration Origin of the Hercules Moving Group with GAIA, LAMOST, APOGEE, and GALAH Surveys
Wu, Yaqian; Zhao, Jingkun; Yoon, Suk-Jin +3 more
Using Gaia DR3 data and the wavelet transformation technique, we study the substructures of the Hercules moving group (HMG): Hercules 1 (H1) and Hercules 2 (H2). Spectroscopic survey data from LAMOST, APOGEE, and GALAH are used to obtain metallicities and ages of stars belonging to the HMG. Our analysis leads to several key findings as follows: (a…
The effect of variations in the magnetic field direction from turbulence on kinetic-scale instabilities
Verscharen, Daniel; Chen, Christopher H. K.; Opie, Simon +2 more
At kinetic scales in the solar wind, instabilities transfer energy from particles to fluctuations in the electromagnetic fields while restoring plasma conditions towards thermodynamic equilibrium. We investigate the interplay between background turbulent fluctuations at the small-scale end of the inertial range and kinetic instabilities acting to …
The Influence of the Galactic Bar on the Dynamics of Globular Clusters
Carraro, Giovanni; Korchagin, Vladimir; Tkachenko, Roman +2 more
We make use of recent estimates for the parameters of the Milky Way's halo globular clusters and study the influence of the galactic bar on the dynamics of these clusters by computing their orbits. We use both an axisymmetric and non-axisymmetric galactic potentials, which include the rotating elongated bar/bulge structure. We account for observat…