129 citations · 1k across the 44 of their papers we have counts for
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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…
Interferometric Images of the Starspot Evolution of Andromedae
Rachael M. Roettenbacher, John D. Monnier, Heidi Korhonen +21
The evolution of starspots of the giant primaries of RS CVn systems is typically detected indirectly with photometric and spectroscopic monitoring. These observations suggest slowl…
Digging deeper into the dense Galactic globular cluster Terzan 5 with Electron-Multiplying CCDs. Variable star detection and new discoveries
R. Figuera Jaimes, M. Catelan, K. Horne +20
Context. High frame-rate imaging was employed to mitigate the effects of atmospheric turbulence (seeing) in observations of globular cluster Terzan 5. Aims. High-precision time-ser…
Gaia21blx: Complete resolution of a binary microlensing event in the Galactic disk
P. Rota, V. Bozza, M. Hundertmark +22
Context. Gravitational microlensing is a method that is used to discover planet-hosting systems at distances of several kiloparsec in the Galactic disk and bulge. We present the an…
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…
Detection of weak magnetic fields in two HgMn stars
S. Hubrig, S. P. Jarvinen, H. Korhonen +4
The main-sequence mercury-manganese (HgMn) stars are known to exhibit large overabundances of exotic elements and, similar to magnetic Ap/Bp stars, are spectrum variables, implying…
A census of Coronal Mass Ejections on solar-like stars
M. Leitzinger, P. Odert, R. Greimel +8
Coronal Mass Ejections (CMEs) may have major importance for planetary and stellar evolution. Stellar CME parameters, such as mass and velocity, have yet not been determined statist…
Weak Magnetic Fields in Two Herbig Ae Systems: The SB2 AK Sco and the Presumed Binary HD 95881
S. P. Järvinen, T. A. Carroll, S. Hubrig +9
We report the detection of weak mean longitudinal magnetic fields in the Herbig Ae double-lined spectroscopic binary AK Sco and in the presumed spectroscopic Herbig Ae binary HD958…
Do A-type stars flare?
M. G. Pedersen, V. Antoci, H. Korhonen +5
For flares to be generated, stars have to have a sufficiently deep outer convection zone (F5 and later), strong large--scale magnetic fields (Ap/Bp-type stars) or strong, radiative…
Surface magnetism of cool stars
O. Kochukhov, P. Petit, K. G. Strassmeier +10
Magnetic fields are essential ingredients of many physical processes in the interiors and envelopes of cool stars. Yet their direct detection and characterisation is notoriously di…
Chemical spots on the surface of the strongly magnetic Herbig Ae star HD 101412
S. P. Järvinen, S. Hubrig, M. Schöller +3
Due to the knowledge of the rotation period and the presence of a rather strong surface magnetic field, the sharp-lined young Herbig Ae star HD 101412 with a rotation period of 42…
Exploring the crowded central region of 10 Galactic globular clusters using EMCCDs. Variable star searches and new discoveries
R. Figuera Jaimes, D. M. Bramich, J. Skottfelt +31
Obtain time-series photometry of the very crowded central regions of Galactic globular clusters with better angular resolution than previously achieved with conventional CCDs on gr…
HARPS spectropolarimetry of three sharp-lined Herbig Ae stars: New insights
S. P. Järvinen, T. A. Carroll, S. Hubrig +5
Several arguments have been presented that favour a scenario in which the low detection rate of magnetic fields in Herbig Ae stars can be explained by the weakness of these fields…
A Census of Variability in Globular Cluster M68 (NGC 4590)
N. Kains, A. Arellano Ferro, R. Figuera Jaimes +32
We analyse 20 nights of CCD observations in the V and I bands of the globular cluster M68 (NGC 4590), using these to detect variable objects. We also obtained electron-multiplying…
Abundance analysis, spectral variability, and search for the presence of a magnetic field in the typical PGa star HD19400
S. Hubrig, F. Castelli, J. F. Gonzalez +6
The aim of this study is to carry out an abundance determination, to search for spectral variability and for the presence of a weak magnetic field in the typical PGa star HD19400.…
A detailed census of variable stars in the globular cluster NGC 6333 (M9) from CCD differential photometry
A. Arellano Ferro, D. M. Bramich, R. Figuera Jaimes +37
We report CCD and time-series photometry of the globular cluster NGC 6333 (M9). The technique of difference image analysis has been used, which enables photometric precisio…
Estimating the parameters of globular cluster M 30 (NGC 7099) from time-series photometry
N. Kains, D. M. Bramich, A. Arellano Ferro +47
We present the analysis of 26 nights of V and I time-series observations from 2011 and 2012 of the globular cluster M 30 (NGC 7099). We used our data to search for variable stars i…
EMCCD photometry reveals two new variable stars in the crowded central region of the globular cluster NGC 6981
Jesper Skottfelt, D. M. Bramich, R. Figuera Jaimes +33
Two previously unknown variable stars in the crowded central region of the globular cluster NGC 6981 are presented. The observations were made using the Electron Multiplying CCD (E…
Doppler imaging of stellar surface structure - XXIV. The lithium-rich single K-giants DP Canum Venaticorum and DI Piscium
Zs. Kovari, H. Korhonen, K. G. Strassmeier +3
We present the first Doppler imaging study of the two rapidly rotating, single K-giants DP CVn and DI Psc in order to study the surface spot configuration and to pinpoint their ste…
Magnetic fields of HgMn stars
S. Hubrig, J. F. Gonzalez, I. Ilyin +8
The frequent presence of weak magnetic fields on the surface of spotted late-B stars with HgMn peculiarity in binary systems has been controversial during the two last decades. We…
Photometric and spectroscopic observations of three rapidly rotating late-type stars: EY Dra, V374 Peg and GSC 02038-00293
H. Korhonen, K. Vida, M. Husarik +3
Here, BV(RI)c broad band photometry and intermediate resolution spectroscopy in Halpha region are presented for two rapidly rotating late-type stars: EY Dra and V374 Peg. For a thi…