Search Publications
The R-Process Alliance: 2MASS J22132050–5137385, the Star with the Highest-known r-process Enhancement at [Eu/Fe] = +2.45
Beers, Timothy C.; Placco, Vinicius M.; Hattori, Kohei +6 more
We present stellar parameters and chemical abundances of 47 elements detected in the bright (V = 11.63) very metal-poor ([Fe/H] = ‑2.20 ± 0.12) star 2MASS J22132050‑5137385. We observed this star using the Magellan Inamori Kyocera Echelle spectrograph as part of ongoing work by the R-Process Alliance. The spectrum of 2MASS J22132050‑5137385 exhibi…
Modelling the orbital histories of satellites of Milky Way-mass galaxies: testing static host potentials against cosmological simulations
Wetzel, Andrew; Sanderson, Robyn E.; Patel, Ekta +3 more
Understanding the evolution of satellite galaxies of the Milky Way (MW) and M31 requires modelling their orbital histories across cosmic time. Many works that model satellite orbits incorrectly assume or approximate that the host halo gravitational potential is fixed in time and is spherically symmetric or axisymmetric. We rigorously benchmark the…
New Synoptic Observations of the Cosmic Optical Background with New Horizons
Singer, Kelsi N.; Stern, S. Alan; Weaver, Harold A. +11 more
We obtained New Horizons LORRI images to measure the cosmic optical background (COB) intensity integrated over 0.4 µm ≲ λ ≲ 0.9 µm. The survey comprises 16 high-Galactic-latitude fields selected to minimize scattered diffuse Galactic light (DGL) from the Milky Way, as well as scattered light from bright stars. This work supersedes an e…
Seven classes of rotational variables from a study of 50 000 spotted stars with ASAS-SN, Gaia, and APOGEE
Kochanek, C. S.; Pinsonneault, Marc; Cao, Lyra +4 more
We examine the properties of ~50 000 rotational variables from the ASAS-SN survey using distances, stellar properties, and probes of binarity from Gaia DR3 and the SDSS APOGEE survey. They have higher amplitudes and span a broader period range than previously studied Kepler rotators. We find they divide into three groups of main sequence stars (MS…
Age uncertainties of red giants due to cumulative rotational mixing of progenitors calibrated by asteroseismology
Aerts, C.; Van Reeth, T.; Fritzewski, D. J. +2 more
Context. Galactic archaeology largely relies on precise ages of distant evolved stars in the Milky Way. Nowadays, asteroseismology can deliver ages for many red giants observed with high-cadence, high-precision photometric space missions such as CoRoT, Kepler, K2, TESS, and soon PLATO.
Aims: Our aim is to quantify the age uncertainties of cur…
Variable stars in galactic globular clusters. I. The population of RR Lyrae stars
Anderson, Richard I.; Cruz Reyes, Mauricio; Netzel, Henryka +2 more
We present a comprehensive catalog of 2824 RR Lyrae stars (RRLs) residing in 115 Galactic globular clusters (GCs). Our catalog includes 1594 fundamental-mode (RRab), 824 first-overtone (RRc), and 28 double-mode (RRd) RRLs, as well as 378 RRLs of an unknown pulsation mode. We cross-matched 481 349 RRLs reported in the third Data Release (DR3) of th…
Comprehensive High-resolution Chemical Spectroscopy of Barnard's Star with SPIRou
Carmona, Andrés; Gaidos, Eric; Vandal, Thomas +17 more
Determination of fundamental parameters of stars impacts all fields of astrophysics, from galaxy evolution to constraining the internal structure of exoplanets. This paper presents a detailed spectroscopic analysis of Barnard's star (otherwise known as Gl 699) that compares an exceptionally high-quality (an average signal-to-noise ratio of ∼1000 i…
Age-dating the young open cluster UBC 1 with g-mode asteroseismology, gyrochronology, and isochrone fitting
Aerts, C.; Li, G.; Van Reeth, T. +3 more
Aims: UBC 1 is an open cluster discovered in Gaia data and located near the edge of the Transiting Exoplanet Survey Satellite's (TESS) continuous viewing zone. We aim to provide age constraints for this poorly studied open cluster from the combination of gravity-mode (g-mode) asteroseismology, gyrochronology, and isochrone fitting.
Metho…
A low-mass helium star progenitor model for the Type Ibn SN 2020nxt
Van Dyk, Schuyler D.; Filippenko, Alexei V.; Chambers, Kenneth C. +55 more
A growing number of supernovae (SNe) are now known to exhibit evidence for significant interaction with a dense, pre-existing, circumstellar medium (CSM). SNe Ibn comprise one such class that can be characterized by both rapidly evolving light curves and persistent narrow He I lines. The origin of such a dense CSM in these systems remains a pressi…
Spinning primordial black holes from first order phase transition
Banerjee, Indra Kumar; Dey, Ujjal Kumar
We conduct a novel study to obtain the initial spin of the primordial black holes created during a first-order phase transition due to delayed false vacuum decay. Remaining within the parameter space consistent with observational bounds, we express the abundance and the initial spin of the primordial black holes as functions of the phase transitio…