A5017106450- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Astronomical Observations and Instrumentation
- Earthquake Detection and Analysis
- Calibration and Measurement Techniques
- Historical Astronomy and Related Studies
- History and Developments in Astronomy
- Atmospheric Ozone and Climate
- Geophysics and Gravity Measurements
- Inertial Sensor and Navigation
- Impact of Light on Environment and Health
- Adaptive optics and wavefront sensing
- Geomagnetism and Paleomagnetism Studies
- Ionosphere and magnetosphere dynamics
- earthquake and tectonic studies
- Historical and Architectural Studies
- Gamma-ray bursts and supernovae
- Spacecraft Design and Technology
- Occupational health in dentistry
Leibniz Institute for Astrophysics Potsdam
2023-2024
Max Planck Institute for Solar System Research
2017-2020
University of Göttingen
2017-2020
Max Planck Society
2020
Magnetic activity of the Sun and other stars causes their brightness to vary. We investigate how typical Sun's variability is compared solar-like stars, i.e. those with near-solar effective temperatures rotation periods. By combining four years photometric observations from Kepler space telescope astrometric data Gaia spacecraft, we measure variabilities 369 stars. Most well-determined periods show higher than are therefore considerably more active. These appear nearly identical Sun, except...
Context. Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity Earth, solar can serve as a stepping stone for understanding stellar counterparts, especially when using Sun-as-a-star instrument and in combination with resolved observations. Aims. We aim understand disk-integrated behaviors of confined X2.2 flare its eruptive X9.3 successor, had energies 2.2 × 10 31 erg 9.3 erg,...
Twenty-four years after the discoveries of first exoplanets, radial-velocity (RV) method is still one most productive techniques to detect and confirm exoplanets. But stellar magnetic activity can induce RV variations large enough make it difficult disentangle planet signals from noise. In this context, HD41248 an interesting planet-host candidate, with observations plagued by activity-induced signals. We report on ESPRESSO analyse them together previous HARPS goal evaluating presence...
The current and upcoming high precision photometric surveys such as TESS, CHEOPS, PLATO will provide the community with thousands of new exoplanet candidates. As a consequence, presence correlation is crucial in selecting targets lowest RV jitter for efficient follow-up exoplanetary Studies this type are also to design optimized observational strategies mitigate when searching Earth-mass exoplanets. Our goal assess between high-precision variability measurements over different time scales....
Whether the Sun is an ordinary G-type star still open scientific question. Stellar surveys by Kepler and TESS however, have revealed that Sun-like stars tend to show much stronger flare activity than Sun. This study aims reassess observed spot of fine-tuning criteria for a more robust definition conditions better comparability between current stars. We updated one recent stellar samples applying new empirical relations starspot size effective temperature derive reliable group sizes. From 265...
Context. Considerable effort has been put into using light curves observed by space telescopes such as CoRoT, Kepler and TESS for determining stellar rotation periods. While periods of active stars can be reliably determined, the many older less (e.g. similar to Sun) are quite irregular, which hampers determination their Aims. We examine factors causing irregularities in brightness variations develop a method low activity with irregular curves. Methods. extend Spectral And Total Irradiance...
Context. Young and active stars generally have regular, almost sinusoidal, patterns of variability attributed to their rotation, while the majority older less stars, including Sun, more complex non-regular light curves, which do not clear rotational-modulation signals. Consequently, rotation periods been successfully determined only for a small fraction Sun-like (mainly ones) observed by transit-based planet-hunting missions, such as CoRoT, Kepler , TESS. This suggests that systems properly...
A comprehensive multi-wavelength campaign has been carried out to probe stellar activity and variability in the young Sun-like star $\iota$-Horologii. We present results from long-term spectropolarimetric monitoring of system by using ultra-stable spectropolarimeter/velocimeter HARPS at ESO 3.6-m telescope. Additionally, we included high-precision photometry NASA Transiting Exoplanet Survey Satellite (TESS) observations far- near-ultraviolet spectral regions STIS instrument on NASA/ESA...
A former member of the Hyades cluster, ι Horologii (ι Hor) is a planet-hosting Sun-like star which displays shortest coronal activity cycle known to date (Pcyc ∼ 1.6 yr). With an age ∼625 Myr, Hor also youngest with detected cycle. The study its magnetic properties holds potential provide fundamental information understand origin cyclic and stellar magnetism in late-type stars. In this series papers, we present results comprehensive project aimed at studying evolving field how evolution...
We report on the determination of lithium abundance [A(Li)] 52 solar-like stars. For 41 objects A(Li) here presented corresponds to first measurement. have measured equivalent widths 6708\AA\ feature in high-resolution spectroscopic images ($R \sim 80\,000$), obtained at Observatorio Astrof\'isico Guillermo Haro (Sonora, Mexico), as part scientific observations revitalized Lunar and Planetary Laboratory (LPL) Echelle Spectrograph, now known Cananea High-resolution Spectrograph (CanHiS)....
Stellar rotation periods can be determined by observing brightness variations caused active magnetic regions transiting visible stellar disk as the star rotates. The successful photometric surveys stemming from Kepler and TESS observations led to determination of in tens thousands young stars. However, there is still a lack information about older less stars, like Sun. irregular temporal profiles light curves decay times regions, which are comparable or even shorter than periods, combine...
Stellar flares cannot be spatially resolved, which complicates ascertaining the physical processes behind particular spectral signatures. Due to their proximity Earth, solar can serve as a stepping stone for understanding stellar counterparts, especially when using Sun-as-a-star instrument and in combination with resolved observations. We aim understand disk-integrated behaviors of confined X2.2 flare its eruptive X9.3 successor measured by HARPS-N. The behavior multiple photospheric...
Coronal Mass Ejections (CMEs) remain a focal point of solar and stellar research due to their significant impact on space weather dynamics exoplanet habitability. Unfortunately, it has so far proven difficult measure these events other stars, with only handful confirmed detections.  On the Sun, strong flares (X1-class above) are almost always accompanied by CME. This connection not been found for where regularly detected without CME counterpart. To investigate this discrepancy we...
The ArmazoNes high Dispersion Echelle Spectrograph (ANDES) is the optical and near-infrared high-resolution echelle spectrograph envisioned for European Extremely Large Telescope (ELT). We present a selection of science cases, supported by new calculations simulations, where ANDES could enable major advances in fields stars stellar populations. focus on three key areas, including physics atmospheres, structure, evolution; Milky Way, Local Group, beyond; star-planet connection. features are...
This is our reply to the comment of T. Metcalfe and J. van Saders on Science report "The Sun less active than other solar-like stars" by Reinhold, A. I. Shapiro, S. K. Solanki, B. Montet, N. Krivova, R. H. Cameron, E. M. Amazo-Gomez. We hope that both lead fruitful discussions which two presented scenarios more likely.
Abstract PolarBase contains stellar spectropolarimetric data collected with the NARVAL & ESPaDOnS instruments (Petit et al . 2014). Their respective spectral resolutions are 65 000 and 68 000, in mode. As first part of this work, we use repositories. We selected spectra from a sample cool stars effective Temperature ( T eff ) ranging between 4900 to 6000 K. This systems without reported exoplanets. exploit full wavelength range 380 900 nm order obtain chromospheric indexes such as Ca ii...
A comprehensive multi-wavelength campaign has been carried out to probe stellar activity and variability in the young Sun-like star $ι$-Horologii. We present results from long-term spectropolarimetric monitoring of system by using ultra-stable spectropolarimeter/velocimeter HARPS at ESO 3.6-m telescope. Additionally, we included high-precision photometry NASA Transiting Exoplanet Survey Satellite (TESS) observations far- near-ultraviolet spectral regions STIS instrument on NASA/ESA Hubble...