100 citations · 931 across the 32 of their papers we have counts for
21 papers · 1 filter
Atmospheric parameters and abundances of cool red giant stars
Z. Dencs, A. Derekas, T. Mitnyan +10
Understanding the atmospheric parameters of stars on the top of the RGB is essential to reveal the chemical composition of the Milky Way, as they can be used to probe the farthest…
Unresolved Rossby and gravity modes in 214 A and F stars showing rotational modulation
Andreea I. Henriksen, Victoria Antoci, Hideyuki Saio +9
Here we report an ensemble study of 214 A- and F-type stars observed by \textit{Kepler}, exhibiting the so-called \textit{hump and spike} periodic signal, explained by Rossby modes…
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…
FX UMa: A New Heartbeat Binary System with Linear and Non-linear Tidal Oscillations and delta Sct Pulsations
Kun Wang, Anbing Ren, Mads Fredslund Andersen +3
We present a detailed analysis of an eclipsing double-lined binary FX UMa based on TESS photometry and newly acquired spectroscopic observations. The radial velocities and atmosphe…
No swan song for Sun-as-a-star helioseismology: performances of the Solar-SONG prototype for individual mode characterisation
S. N. Breton, P. L. Pallé, R. A. García +5
The GOLF instrument on board SoHO has been in operation for almost 25 years but aging of the instrument has now strongly affected its performance, especially in the low-frequency p…
Precise radial velocities of giant stars XV. Mysterious nearly periodic radial velocity variations in the eccentric binary Cygni
Paul Heeren, Sabine Reffert, Trifon Trifonov +10
Using the Hamilton Echelle Spectrograph at Lick Observatory, we have obtained precise radial velocities (RVs) of a sample of 373 G- and K-giant stars over more than 12 years, leadi…
Observing the changing surface structures of the active K giant sigma Gem with SONG
H. Korhonen, R. M. Roettenbacher, S. Gu +6
Aims: We aim to study the spot evolution and differential rotation in the magnetically active cool K-type giant star sigma Gem from broadband photometry and continuous spectroscopi…
Sun-like Oscillations in the Population II giant HD 122563
Orlagh Creevey, Frédéric Thévenin, Frank Grundahl +8
We have been monitoring the metal-poor Population II giant, HD 122563, for radial velocity variations since 2016 using the SONG telescope on Tenerife. We have detected the global s…
Doppler imaging and differential rotation of Coronae Borealis using SONG
Yue Xiang, Shenghong Gu, A. Collier Cameron +6
We present new Doppler images of both components of the double-lined binary CrB, based on the high-resolution spectroscopic data collected during 11 nights in 2015 March--A…
Oscillations in the Sun with SONG: Setting the scale for asteroseismic investigations
M. Fredslund Andersen, P. Pallé, J. Jessen-Hansen +12
Context. We present the first high-cadence multi-wavelength radial-velocity observations of the Sun-as-a-star, carried out during 57 consecutive days using the stellar échelle spec…
Asteroseismology of the Hyades red giant and planet host epsilon Tauri
Torben Arentoft, Frank Grundahl, Timothy R. White +23
Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-s…
First detection of oscillations in the Halo giant HD 122563: validation of seismic scaling relations and new fundamental parameters
Orlagh Creevey, Frank Grundahl, Frédéric Thévenin +8
The nearby metal-poor giant HD122563 is an important astrophysical laboratory for which to test stellar atmospheric and interior physics. It is also a benchmark star for which to c…
The mass and age of the first SONG target: the red giant 46 LMi
S. Frandsen, M. Fredslund Andersen, K. Brogaard +12
The Stellar Observation Network Group (SONG) is an initiative to build a worldwide network of 1m telescopes with highprecision radial-velocity spectrographs. Here we analyse the fi…
Low-frequency photospheric and wind variability in the early-B supergiant HD 2905
S. Simón-Díaz, C. Aerts, M. A. Urbaneja +5
Despite the important advances in space asteroseismology during the last decade, the early phases of evolution of stars with masses above 15 M have been only vaguel…
Beyond the Kepler/K2 bright limit: variability in the seven brightest members of the Pleiades
T. R. White, B. J. S. Pope, V. Antoci +20
The most powerful tests of stellar models come from the brightest stars in the sky, for which complementary techniques, such as astrometry, asteroseismology, spectroscopy, and inte…
Kepler sheds new and unprecedented light on the variability of a blue supergiant: gravity waves in the O9.5Iab star HD 188209
C. Aerts, S. Simon-Diaz, S. Bloemen +12
Stellar evolution models are most uncertain for evolved massive stars. Asteroseismology based on high-precision uninterrupted space photometry has become a new way to test the outc…
Lithium abundance and rotation of seismic solar analogues - Solar and stellar connection from Kepler and Hermes observations
P. G. Beck, J. -D. do Nascimento, T. Duarte +13
Lithium abundance A(Li) and surface rotation are good diagnostic tools to probe the internal mixing and angular momentum transfer in stars. We explore the relation between surface…
First Results From The Hertzsprung Song Telescope: Asteroseismology Of The G5 Subgiant Star {\Mu}Her
F. Grundahl, M. Fredslund Andersen, J. Christensen-Dalsgaard +26
We report the first asteroseismic results obtained with the Hertzsprung SONG Telescope from an extensive high-precision radial-velocity observing campaign of the subgiant muHerculi…
Probing seismic solar analogues through observations with the NASA Kepler space telescope and HERMES high-resolution spectrograph
P. G. Beck, D. Salabert, R. A. García +21
Stars similar to the Sun, known as solar analogues, provide an excellent opportunity to study the preceding and following evolutionary phases of our host star. The unprecedented qu…
Photospheric and chromospheric magnetic activity of seismic solar analogs. Observational inputs on the solar/stellar connection from Kepler and Hermes
D. Salabert, R. A. Garcia, P. G. Beck +8
We identify a set of 18 solar analogs among the seismic sample of solar-like stars observed by the Kepler satellite rotating between 10 and 40 days. This set is constructed using t…
Atmospheric parameters of 82 red giants in the Kepler field
A. O. Thygesen, S. Frandsen, H. Bruntt +10
Context: Accurate fundamental parameters of stars are essential for the asteroseismic analysis of data from the NASA Kepler mission. Aims: We aim at determining accurate atmospheri…