Publications (27)
Loss and fractionation of noble gas isotopes and moderately volatile elements from planetary embryos and early Venus, Earth and Mars
H. Lammer, M. Scherf, H. Kurokawa +12
Here we discuss the current state of knowledge on how atmospheric escape processes can fractionate noble gas isotopes and moderately volatile rock-forming elements that populate pr…
Probing the Blow-Off Criteria of Hydrogen-Rich "Super-Earths"
H. Lammer, N. V. Erkaev, P. Odert +3
The discovery of transiting "super-Earths" with inflated radii and known masses such as Kepler-11b-f, GJ 1214b and 55 Cnc e, indicates that these exoplanets did not lose their nebu…
PLATOSpec: a precise spectrograph in support of space missions
P. Kabáth, M. Skarka, A. Hatzes +42
The upcoming space missions that will characterize exoplanets, such as PLATO and Ariel, will collect huge amounts of data that will need to be complemented with ground-based observ…
Rossby waves and polar spots in rapidly rotating stars: Implications for stellar wind evolution
T. V. Zaqarashvili, R. Oliver, J. L. Ballester +5
Rapidly rotating stars show short-period oscillations in magnetic activity and polar appearance of starspots. The aim of this paper is to study large-scale shallow water waves in t…
Stellar Aspects of Habitability: Characterizing Target Stars for Terrestrial Planet Search Missions
L. Kaltenegger, C. Eiroa, I. Ribas +7
In this paper we present and discuss the criteria for selecting potential target stars suitable for the search for Earth like planets, with a special emphasis on the stellar aspect…
Spectroscopic observations of flares and superflares on AU Mic
P. Odert, M. Leitzinger, R. Greimel +13
The young active flare star AU~Mic is the planet host star with the highest flare rate from TESS data. Therefore, it represents an ideal target for dedicated ground-based monitorin…
Stellar Coronal Mass Ejections I. Estimating occurrence frequencies and mass-loss rates
P. Odert, M. Leitzinger, A. Hanslmeier +1
Stellar coronal mass ejections (CMEs) may play an important role in mass- and angular momentum loss of young Sun-like stars. If occurring frequently, they may also have a strong ef…
Stellar coronal mass ejections II. Constraints from spectroscopic observations
P. Odert, M. Leitzinger, E. W. Guenther +1
Detections of stellar coronal mass ejections (CMEs) are still rare. Observations of strong Balmer line asymmetries during flare events have been interpreted as being caused by CMEs…
Indications of stellar prominence oscillations on fast rotating stars: the cases of HK Aqr and PZ Tel
M. Leitzinger, P. Odert, T. V. Zaqarashvili +3
We present the analysis of six nights of spectroscopic monitoring of two young and fast rotating late-type stars, namely the dMe star HK Aqr and the dG/dK star PZ Tel. On both star…
The DWARF project: Eclipsing binaries - precise clocks to discover exoplanets
T. Pribulla, M. VaÅko, M. Ammler - von Eiff +53
We present a new observational campaign, DWARF, aimed at detection of circumbinary extrasolar planets using the timing of the minima of low-mass eclipsing binaries. The observation…
XUV exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets II: Hydrogen coronae and ion escape
K. G. Kislyakova, H. Lammer, M. Holmström +8
We study the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and hydrogen-rich upper atmospheres of an Earth-like planet and a "super-Earth"…
Formation of Venus, Earth and Mars: Constrained by isotopes
H. Lammer, R. Brasser, A. Johansen +2
We discuss the current state of knowledge of terrestrial planet formation from the aspects of different planet formation models and isotopic data from 182Hf-182W, U-Pb, lithophile-…
A confined dynamo: magnetic activity of the K-dwarf component in the pre-cataclysmic binary system V471 Tauri
Zs. KÅvári, L. Kriskovics, K. Oláh +6
We scrutinize the red dwarf component in the eclipsing binary system V471 Tau in order to unravel relations between different activity layers from the stellar surface through the c…
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…
Spectroscopic investigation of the southern late-K/early-M dwarf binary CC Eri
M. Leitzinger, P. Odert, R. Greimel +6
In the recent past investigations of stellar Coronal Mass Ejections (CMEs) and flares/superflares gained special attention because of their relevance for planetary habitability and…
A search for flares and mass ejections on young late-type stars in the open cluster Blanco-1
M. Leitzinger, P. Odert, R. Greimel +5
We present a search for stellar activity (flares and mass ejections) in a sample of 28 stars in the young open cluster Blanco-1. We use optical spectra obtained with ESO's VIMOS mu…
MICADO: first light imager for the E-ELT
R. Davies, J. Schubert, M. Hartl +80
MICADO will equip the E-ELT with a first light capability for diffraction limited imaging at near-infrared wavelengths. The instrument's observing modes focus on various flavours o…
Escape of the martian protoatmosphere and initial water inventory
N. V. Erkaev, H. Lammer, L. Elkins-Tanton +8
Latest research in planet formation indicate that Mars formed within a few million years (Myr) and remained a planetary embryo that never grew to a more massive planet. It can also…
Observations and detectability of young Suns' flaring and CME activity in optical spectra
M. Leitzinger, P. Odert, R. Greimel
The Sun's history is still a subject of interest to modern astrophysics. Observationally constrained CME rates of young solar analogues are still lacking, as those require dedicate…
Origin and Loss of nebula-captured hydrogen envelopes from "sub"- to "super-Earths" in the habitable zone of Sun-like stars
H. Lammer, A. Stökl, N. V. Erkaev +6
We investigate the origin and loss of captured hydrogen envelopes from protoplanets between `sub-Earth'-like bodies of 0.1 up to `super-Earths' with 5 in th…
Future mmVLBI Research with ALMA: A European vision
R. P. J. Tilanus, T. P. Krichbaum, J. A. Zensus +165
Very long baseline interferometry at millimetre/submillimetre wavelengths (mmVLBI) offers the highest achievable spatial resolution at any wavelength in astronomy. The anticipated…
Flares and superflares on the southern active binary CC Eri
M. Leitzinger, P. Odert, R. Greimel +15
Flares and CMEs are known to be the dominating high-energy phenomena on cool stars. Superflares were thoroughly investigated using broadband photometry predominantly from Kepler, K…
Modeling the Ly transit absorption of the hot Jupiter HD 189733b
P. Odert, N. V. Erkaev, K. G. Kislyakova +7
Hydrogen-dominated atmospheres of hot exoplanets expand and escape due to the intense heating by the X-ray and extreme ultraviolet (XUV) irradiation of their host stars. Excess abs…
Spectroscopy of flares on AU Mic
P. Odert, M. Leitzinger, P. Kabáth +6
Photometric space missions like Kepler and TESS have revealed unprecedented statistics of stellar flares, including the frequent detection of highly energetic superflares. Spectros…
Modification of the radioactive heat budget of Earth-like exoplanets by the loss of primordial atmospheres
N. Erkaev, M. Scherf, O. Herbort +6
The initial abundance of radioactive heat producing isotopes in the interior of a terrestrial planet are important drivers of its thermal evolution and the related tectonics and po…
Escape and fractionation of volatiles and noble gases from Mars-sized planetary embryos and growing protoplanets
P. Odert, H. Lammer, N. V. Erkaev +6
Planetary embryos form protoplanets via mutual collisions, which can lead to the development of magma oceans. During their solidification, large amounts of the mantles' volatile co…
Investigating magnetic activity in very stable stellar magnetic fields: long-term photometric and spectroscopic study of the fully convective M4 dwarf V374 Peg
K. Vida, L. Kriskovics, K. Oláh +8
The ultrafast-rotating () fully convective single M4 dwarf V374 Peg is a well-known laboratory for studying intense stellar activity in a stable magnet…