411 citations · 1.8k across the 55 of their papers we have counts for
55 papers
Simulated Coronal Mass Ejections on a young Solar-Type Star and the Associated Instantaneous Angular Momentum Loss
Yu Xu, Julián D. Alvarado-Gómez, Hui Tian +3
Coronal mass ejections (CMEs) on stars can change the stars' magnetic field configurations and mass loss rates during the eruption and propagation and therefore, may affect the sta…
The first evidence of tidally induced activity in a brown dwarf-M dwarf pair: A Chandra study of the NLTT 41135/41136 system
Nikoleta Ilić, Katja Poppenhaeger, Desmond Dsouza +3
The magnetic activity of low-mass stars changes as they age. The primary process decreasing the stellar activity level is the angular momentum loss via magnetized stellar wind. How…
Far beyond the Sun: II. Probing the stellar magnetism of the young Sun ι Horologii from the photosphere to its corona
E. M. Amazo-Gómez, J. D. Alvarado-Gómez, K. Poppenhaeger +14
A comprehensive multi-wavelength campaign has been carried out to probe stellar activity and variability in the young Sun-like star -Horologii. We present the results from long-…
The PEPSI Exoplanet Transit Survey. III: The detection of FeI, CrI and TiI in the atmosphere of MASCARA-1 b through high-resolution emission spectroscopy
G. Scandariato, F. Borsa, A. S. Bonomo +19
Hot giant planets like MASCARA-1 b are expected to have thermally inverted atmospheres, that makes them perfect laboratory for the atmospheric characterization through high-resolut…
Quantification of the environment of cool stars using numerical simulations
J. J. Chebly, J. D. Alvarado-Gómez, K. Poppenhaeger
Stars interact with their planets through gravitation, radiation, and magnetic fields. Although magnetic activity decreases with time, reducing associated high-energy (e.g., corona…
The influence of host star activity evolution on the population of super-Earths and mini-Neptunes
Laura Ketzer, Katja Poppenhaeger
The detected exoplanet population displays a dearth of planets with sizes of about two Earth radii, the so-called radius gap. This is interpreted as an evolutionary effect driven b…
The PEPSI Exoplanet Transit Survey (PETS). II. A Deep Search for Thermal Inversion Agents in KELT-20 b/MASCARA-2 b with Emission and Transmission Spectroscopy
Marshall C. Johnson, Ji Wang, Anusha Pai Asnodkar +19
Recent observations have shown that the atmospheres of ultra hot Jupiters (UHJs) commonly possess temperature inversions, where the temperature increases with increasing altitude.…
The PEPSI Exoplanet Transit Survey (PETS) I: Investigating the presence of a silicate atmosphere on the super-Earth 55 Cnc e
Engin Keles, Matthias Mallonn, Daniel Kitzmann +26
The study of exoplanets and especially their atmospheres can reveal key insights on their evolution by identifying specific atmospheric species. For such atmospheric investigations…
Tidal star-planet interaction and its observed impact on stellar activity in planet-hosting wide binary systems
Nikoleta Ilic, Katja Poppenhaeger, S. Marzieh Hosseini
Tidal interaction between an exoplanet and its host star is a possible pathway to transfer angular momentum between the planetary orbit and the stellar spin. In cases where the pla…
Helium absorption in exoplanet atmospheres is connected to stellar coronal abundances
K. Poppenhaeger
Transit observations in the helium triplet around 10830 Angstrom are a successful tool to study exoplanetary atmospheres and their mass loss. Forming those lines requires ionisatio…
Simulating the Space Weather in the AU Mic System: Stellar Winds and Extreme Coronal Mass Ejections
Julián D. Alvarado-Gómez, Ofer Cohen, Jeremy J. Drake +7
Two close-in planets have been recently found around the M-dwarf flare star AU Microscopii (AU Mic). These Neptune-sized planets (AU Mic b and c) seem to be located very close to t…
Identifying interesting planetary systems for future X-ray observations
Grace Foster, Katja Poppenhaeger
X-ray observations of star-planet systems are important to grow our understanding of exoplanets; these observation allow for studies of photoevaporation of the exoplanetary atmosph…
Estimating photoevaporative mass loss of exoplanets with PLATYPOS
Laura Ketzer, Katja Poppenhaeger
We develop PLATYPOS (PLAneTarY PhOtoevaporation Simulator), a python code to perform planetary photoevaporative mass-loss calculations for close-in planets with hydrogen-helium env…
Localizing flares to understand stellar magnetic fields and space weather in exo-systems
Ekaterina Ilin, Katja Poppenhäger, Julián D. Alvarado-Gómez
Stars are uniform spheres, but only to first order. The way in which stellar rotation and magnetism break this symmetry places important observational constraints on stellar magnet…
Destination exoplanet: Habitability conditions influenced bystellar winds properties
Judy J. Chebly, Julián D. Alvarado-Gómez, Katja Poppenhaeger
The cumulative effect of the magnetized stellar winds on exoplanets dominates over other forms of star-planet interactions. When combined with photoevaporation, these winds will le…
Coronal Mass Ejections and Exoplanets: A Numerical Perspective
Julián D. Alvarado-Gómez, Jeremy J. Drake, Ofer Cohen +3
Coronal mass ejections (CMEs) are more energetic than any other class of solar phenomena. They arise from the rapid release of up to erg of magnetic energy mainly in the…
Detection capability of ground-based meter-sized telescopes for shallow exoplanet transits
M. Mallonn, K. Poppenhaeger, T. Granzer +2
Meter-sized ground-based telescopes are frequently used today for the follow-up of extrasolar planet candidates. While the transit signal of a Jupiter-sized object can typically be…
H-Alpha Variability of V1298 Tau c
Everett Schlawin, Ilya Ilyin, Adina D. Feinstein +5
The 23 Myr system V1298 Tau hosts four transiting planets and is a valuable laboratory for exploring the early stages of planet evolution soon after formation of the star. We obser…
Giant white-light flares on fully convective stars occur at high latitudes
Ekaterina Ilin, Katja Poppenhaeger, Sarah J. Schmidt +7
White-light flares are magnetically driven localized brightenings on the surfaces of stars. Their temporal, spectral, and statistical properties present a treasury of physical info…
Exoplanet X-ray irradiation and evaporation rates with eROSITA
G. Foster, K. Poppenhaeger, N. Ilic +1
High-energy irradiation is a driver for atmospheric evaporation and mass loss in exoplanets. This work is based on data from eROSITA, the soft X-ray instrument aboard SRG (Spectrum…
An Earth-like stellar wind environment for Proxima Centauri c
Julián D. Alvarado-Gómez, Jeremy J. Drake, Cecilia Garraffo +4
A new planet has been recently discovered around Proxima Centauri. With an orbital separation of au and a minimum mass of about , Proxima c is a prime…
Chromospheric emission of solar-type stars with asteroseismic ages
R S Booth, K. Poppenhaeger, C. A. Watson +3
Stellar magnetic activity decays over the main-sequence life of cool stars due to the stellar spin-down driven by magnetic braking. The evolution of chromospheric emission is well-…
Kepler Object of Interest Network III. Kepler-82f: A new non-transiting $21 M_\bigoplus$ planet from photodynamical modelling
J. Freudenthal, C. von Essen, A. Ofir +13
Context. The Kepler Object of Interest Network (KOINet) is a multi-site network of telescopes around the globe organised for follow-up observations of transiting planet candidate K…
NGTS-7Ab: An ultra-short period brown dwarf transiting a tidally-locked and active M dwarf
James A. G. Jackman, Peter J. Wheatley, Dan Bayliss +36
We present the discovery of NGTS-7Ab, a high mass brown dwarf transiting an M dwarf with a period of 16.2 hours, discovered as part of the Next Generation Transit Survey (NGTS). Th…