Search Publications
Detecting stellar activity cycles in p-mode travel times. Proof of concept using SOHO/VIRGO solar observations
Gizon, L.; Vasilyev, V.
Context. The 11 yr solar cycle is known to affect the global modes of solar acoustic oscillations. In particular, p mode frequencies increase with solar activity.
Aims: We propose a new method to detect the solar cycle from the p-mode autocorrelation function, and we validate this method using VIRGO/SPM photometric time series from solar cycl…
The Gaia-ESO Survey: Calibrating the lithium-age relation with open clusters and associations. II. Expanded cluster sample and final membership selection
Prusti, T.; Gilmore, G.; Montes, D. +25 more
Context. The Li abundance observed in pre-main sequence and main sequence late-type stars is strongly age-dependent, but also shows a complex pattern depending on several parameters, such as rotation, chromospheric activity, and metallicity. The best way to calibrate these effects, and with the aim of studying Li as an age indicator for FGK stars,…
Directional discontinuities in the inner heliosphere from Parker Solar Probe and Solar Orbiter observations
Szabo, A.; Opitz, A.; Nemeth, Z. +5 more
Context. Directional discontinuities (DDs) are common structures in the solar wind plasma and are among the most important discontinuities besides shock waves. The Parker Solar Probe and Solar Orbiter spacecraft currently provide whole new insight into the inner heliosphere in spatial coverage and timescales. Aims. We search for DDs and classify t…
Hot subdwarf wind models with accurate abundances. II. Helium-dominated merger products CD-46 8926 and CD-51 11879
Krtička, J.; Vučković, M.; Janík, J. +3 more
Context. Helium-dominated subdwarfs are core helium burning stars stripped of their envelope. The nuclear evolution of these stars alters surface abundances. Modified abundances impact the strength of the stellar wind.
Aims: We aim to understand the influence of modified surface abundances on the strength of the stellar wind in the helium-dom…
Validation of the RR Lyrae period determination in the Pan-STARRS PS1 3π survey with K2
Szabó, Róbert; Molnár, László; Forró, Adrienn +2 more
Context. The Pan-STARRS 3π survey has detected hundreds of thousands of variable stars thanks to its coverage and 4-year time span, even though the sampling of the light curves is relatively sparse. These light curves contain only 10–15 detections in each of the five filters (g, r, i, z, y). During the K2 mission, the Kepler space telescope observ…
Study of hydrated asteroids via their polarimetric properties at low phase angles
Hasegawa, Sunao; Watanabe, Makoto; Ishiguro, Masateru +11 more
Context. Ch-type asteroids are distinctive among other dark asteroids in that they exhibit deep negative polarization branches (NPBs). Nevertheless, the physical and compositional properties that cause their polarimetric distinctiveness are less investigated. Aims. We aim to investigate the polarimetric uniqueness of Ch-type asteroids by making da…
Spectroflat: A generic spectrum and flat-field calibration library for spectro-polarimetric data
Feller, A.; Iglesias, F. A.; Doerr, H. -P. +1 more
Context. Flat-fielding spectro-polarimetric data with one spatial and one spectral dimension is inherently difficult as the imprint of the spectral lines needs to be separated from other wavelength-dependent instrumental effect (e.g., fringes or prefilter profiles) and wavelength-independent effects (e.g., dust and sensor response). Current approa…
Modelling non-radially propagating coronal mass ejections and forecasting the time of their arrival at Earth
Magdalenic, J.; Valentino, A.
We present the study of two solar eruptive events observed on December 7 2020 and October 28 2021. Both events were associated with full halo coronal mass ejections (CMEs) and flares. These events were chosen because they show a strong non-radial direction of propagation in the low corona and their main propagation direction observed in the inner …
Pulse frequency variations and timing noise of MXB 0656–072 during the 2007–2008 type I outbursts and implications for its magnetic field
Santangelo, A.; Serim, M. M.; Baykal, A. +4 more
Aims. We aim to explore the properties of the Be/X-ray binary system MXB 0656–072 from a timing analysis perspective through an investigation of the RXTE/PCA and Fermi/GBM data during its 2007–2008 type I outbursts. Methods. We applied two new techniques, for the first time, along with the conventional Deeter method to produce higher-resolution po…
A type II radio burst associated with solar filament–filament interaction
Zhang, Liang; Chen, Yao; Zheng, Ruisheng
Aims. Solar radio type II bursts are often associated with coronal shocks driven by solar eruptions. In this study, we report a type II burst associated with filament–filament interaction. Methods. Combining the high-quality multiwavelength observations from CHASE, SDO, STEREO, and CALLISTO, we conducted a detailed study of the type II burst assoc…