62 citations · 236 across the 20 of their papers we have counts for
22 papers
TS23/McDonald and FIES/NOT strike again. Two new warm Jupiter systems and outer companions in a third
E. Knudstrup, D. Gandolfi, W. D. Cochran +29
Warm Jupiters (gas giant planets with orbital periods of P8-200 d) are thought to be largely unaffected by the tidal interactions that can erase information about the dynamic…
The Stellar Observations Network Group (SONG) -- A Legacy Archive of Stellar Time-Domain Spectroscopy
M. N. Lund, F. Grundahl, M. S. Fredslund +41
The Stellar Observations Network Group (SONG) network has operated for more than a decade, providing long-baseline, high-cadence spectroscopic observations of bright stars and the…
Asteroseismic investigation of HD 140283: The Methuselah star
M. S. Lundkvist, J. R. Larsen, Y. Li +12
HD 140283 is a well-studied metal-poor subgiant and a Gaia benchmark star, often used for testing stellar models due to its proximity, brightness, and low metallicity ([Fe/H] = -2.…
Glitch analysis and asteroseismic modelling of subgiant Herculis: confirming and interpreting the peak as the helium glitch
Advik Gupta, Kuldeep Verma, Hans Kjeldsen +7
The measurements of pressure-mode and mixed-mode oscillation frequencies in subgiant stars offer a unique opportunity to probe their internal structures -- from the surface to the…
Coupling 1D stellar evolution with 3D-hydrodynamical simulations on-the-fly III: stellar evolution at different metallicities
Yixiao Zhou, Jakob L. Rørsted, Achim Weiss +10
A major weakness in one-dimensional (1D) stellar structure and evolution modeling is the simplified treatment of convection, which leads to erroneous near-surface stratification an…
Pushing the boundaries of asteroseismic individual frequency modelling: unveiling two evolved very-low metallicity red giants
Jens R. Larsen, Jakob L. Rørsted, Victor Aguirre Børsen-Koch +21
Metal-poor stars are key to understanding the first stellar generation in the Galaxy. Asteroseismic characterisation of red giants has traditionally relied on global seismic parame…
A link between rocky exoplanet composition and stellar age
Angharad Weeks, Vincent Van Eylen, Daniel Huber +7
Interior compositions are key for our understanding of Earth-like exoplanets. The composition of the core can influence the presence of a magnetic dynamo and the strength of gravit…
Realising efficient computation of individual frequencies for red-giant models
Jens R. Larsen, Jørgen Christensen-Dalsgaard, Mia S. Lundkvist +3
In order to improve the asteroseismic modelling efforts for red-giant stars, the numerical computation of theoretical individual oscillation modes for evolved red-giant models has…
Low-amplitude solar-like oscillations in the K5 V star Indi A
Mia S. Lundkvist, Hans Kjeldsen, Timothy R. Bedding +17
We have detected solar-like oscillations in the mid K-dwarf Indi A, making it the coolest dwarf to have measured oscillations. The star is noteworthy for harboring a…
Does the scaling relation depend on metallicity? Insights from 3D convection simulations
Yixiao Zhou, Jørgen Christensen-Dalsgaard, Martin Asplund +4
Solar-like oscillations have been detected in thousands of stars thanks to modern space missions. These oscillations have been used to measure stellar masses and ages, which have b…
Asteroseismology and Spectropolarimetry of the Exoplanet Host Star Serpentis
Travis S. Metcalfe, Derek Buzasi, Daniel Huber +31
The bright star Ser hosts a hot Neptune with a minimum mass of 13.6 and a 15.5 day orbit. It also appears to be a solar analog, with a mean rotation period of 25.8 d…
Company for the ultra-high density, ultra-short period sub-Earth GJ 367 b: discovery of two additional low-mass planets at 11.5 and 34 days
Elisa Goffo, Davide Gandolfi, Jo Ann Egger +38
GJ 367 is a bright (V 10.2) M1 V star that has been recently found to host a transiting ultra-short period sub-Earth on a 7.7 hr orbit. With the aim of improving the plan…
A close-in giant planet escapes engulfment by its star
Marc Hon, Daniel Huber, Nicholas Z. Rui +39
When main-sequence stars expand into red giants, they are expected to engulf close-in planets. Until now, the absence of planets with short orbital periods around post-expansion, c…
Solar-like oscillations in Cephei A as seen through SONG and TESS
E. Knudstrup, M. N. Lund, M. Fredslund Andersen +11
Fundamental stellar parameters such as mass and radius are some of the most important building blocks in astronomy, both when it comes to understanding the star itself and when der…
Did Kepler-444 have a long-lived convective core?
Mark Lykke Winther, Víctor Aguirre Børsen-Koch, Jakob Lysgaard Rørsted +2
With the greater power to infer the state of stellar interiors provided by asteroseismology, it has become possible to study the survival of initially convective cores within stars…
Radial velocity confirmation of a hot super-Neptune discovered by TESS with a warm Saturn-mass companion
E. Knudstrup, D. Gandolfi, G. Nowak +59
We report the discovery and confirmation of the planetary system TOI-1288. This late G dwarf harbours two planets: TOI-1288 b and TOI-1288 c. We combine TESS space-borne and ground…
Advanced asteroseismic modelling: breaking the degeneracy between stellar mass and initial helium abundance
Kuldeep Verma, Jakob L. Rørsted, Aldo M. Serenelli +3
Current stellar model predictions of adiabatic oscillation frequencies differ significantly from the corresponding observed frequencies due to the non-adiabatic and poorly understo…
Scaling relations of convective granulation noise across the HR diagram from 3D stellar atmosphere models
Luisa Fernanda Rodríguez Díaz, Lionel Bigot, Víctor Aguirre Børsen-Koch +5
High-precision photometric data from space missions have improved our understanding of stellar granulation. These observations have shown with precision the stochastic brightness f…
Age Determination of Galaxy Merger Remnant Stars using Asteroseismology
Camilla C. Borre, Víctor Aguirre Børsen-Koch, Amina Helmi +12
The Milky Way was shaped by the mergers with several galaxies in the past. We search for remnant stars that were born in these foreign galaxies and assess their ages in an effort t…
PLATO Hare-and-Hounds exercise: Asteroseismic model fitting of main-sequence solar-like pulsators
M. S. Cunha, I. W. Roxburgh, V. Aguirre Børsen-Koch +19
Asteroseismology is a powerful tool to infer fundamental stellar properties. The use of these asteroseismic-inferred properties in a growing number of astrophysical contexts makes…
The BAyesian STellar Algorithm (BASTA): a fitting tool for stellar studies, asteroseismology, exoplanets, and Galactic archaeology
V. Aguirre Børsen-Koch, J. L. Rørsted, A. B. Justesen +16
We introduce the public version of the BAyesian STellar Algorithm (BASTA), an open-source code written in {\tt Python} to determine stellar properties based on a set of astrophysic…
Age-Dating Red Giant Stars Associated with Galactic Disk and Halo Substructures
Samuel K. Grunblatt, Joel C. Zinn, Adrian M. Price-Whelan +12
The vast majority of Milky Way stellar halo stars were likely accreted from a small number (3) of relatively large dwarf galaxy accretion events. However, the timing of t…