251 citations · 1.4k across the 31 of their papers we have counts for
8 papers · 1 filter
Stellar magnetic activity and their influence on the habitability of exoplanets
T. Lüftinger, M. Güdel, C. P. Johnstone
Stellar magnetism, explorable via polarimetry, is a crucial driver of activity, ionization, photodissociation, chemistry and winds in stellar environments. Thus it has an important…
Short-period stellar activity cycles with Kepler photometry
Oleksiy V. Arkhypov, Maxim L. Khodachenko, Helmut Lammer +3
We study the short-periodic component of stellar activity with a cycle periods Pcyc up to 1000 days using the Kepler mission photometry of fast-rotating (rotational periods from 1…
The Coronal Temperatures of Low-Mass Main-Sequence Stars
Colin P. Johnstone, Manuel Güdel
Aims. We study the X-ray emission of low-mass main-sequence stars to derive a reliable general scaling law between coronal temperature and the level of X-ray activity. Methods. We…
The Extreme Ultraviolet and X-Ray Sun in Time: High-Energy Evolutionary Tracks of a Solar-Like Star
Lin Tu, Colin P. Johnstone, Manuel Güdel +1
Aims. We aim to describe the pre-main sequence and main-sequence evolution of X-ray and extreme-ultaviolet radiation of a solar mass star based on its rotational evolution starting…
Stellar wind induced soft X-ray emission from close-in exoplanets
K. G. Kislyakova, L. Fossati, C. P. Johnstone +3
In this paper, we estimate the X-ray emission from close-in exoplanets. We show that the Solar/Stellar Wind Charge Exchange Mechanism (SWCX) which produces soft X-ray emission is v…
Stellar Winds on the Main-Sequence I: Wind Model
C. P. Johnstone, M. Güdel, T. Lüftinger +2
Aims: We develop a method for estimating the properties of stellar winds for low-mass main-sequence stars between masses of 0.4 and 1.1 solar masses at a range of distances from th…