Search Publications
The EBLM project. VI. Mass and radius of five low-mass stars in F+M binaries discovered by the WASP survey
Bouchy, F.; Queloz, D.; Ségransan, D. +26 more
Some M-dwarfs around F-/G-type stars have been measured to be hotter and larger than predicted by stellar evolution models. Inconsistencies between observations and models need to be addressed with more mass, radius, and luminosity measurements of low-mass stars to test and refine evolutionary models. Our aim is to measure the masses, radii and ag…
Exposing the plural nature of molecular clouds. Extracting filaments and the cosmic infrared background against the true scale-free interstellar medium
Schneider, N.; Bontemps, S.; Elia, D. +2 more
We present the Multiscale non-Gaussian Segmentation (MnGSeg) analysis technique. This wavelet-based method combines the analysis of the probability distribution function (PDF) of map fluctuations as a function of spatial scales and the power spectrum analysis of a map. This technique allows us to extract the non-Gaussianities identified in the mul…
Asteroseismology of the Hyades red giant and planet host ɛ Tauri
Christensen-Dalsgaard, J.; Andersen, M. F.; Grundahl, F. +23 more
Context. Asteroseismic analysis of solar-like stars allows us to determine physical parameters such as stellar mass, with a higher precision compared to most other methods. Even in a well-studied cluster such as the Hyades, the masses of the red giant stars are not well known, and previous mass estimates are based on model calculations (isochrones…
Semi-empirical model atmospheres for the chromosphere of the sunspot penumbra and umbral flashes
Rouppe van der Voort, Luc; Henriques, Vasco M. J.; Bose, Souvik +1 more
Context. The solar chromosphere and the lower transition region are believed to play a crucial role in the heating of the solar corona. Models that describe the chromosphere (and the lower transition region), accounting for its highly dynamic and structured character are, so far, found to be lacking. This is partly due to the breakdown of complete…
From solar to stellar flare characteristics. On a new peak size distribution for G-, K-, and M-dwarf star flares
Heber, Bernd; Papaioannou, Athanasios; Herbst, Konstantin +1 more
Context. The connection between solar energetic proton events and X-ray flares has been the focus of many studies over the past 13 yr. In the course of these investigations several peak size distribution functions based on Geostationary Operational Environmental Satellite (GOES) measurements of both quantities have been developed. In more recent s…
Indications of non-conservative mass transfer in AMXPs
Sanna, A.; Papitto, A.; Di Salvo, T. +7 more
Context. Since the discovery of the first accreting millisecond X-ray pulsar (AMXP) SAX J1808.4-3658 in 1998, the family of these sources has kept growing. Currently, it has 22 members. All AMXPs are transients with usually very long quiescence periods, implying that the mass accretion rate in these systems is quite low and not constant. Moreover,…
Gliese 49: activity evolution and detection of a super-Earth. A HADES and CARMENES collaboration
Schmitt, J. H. M. M.; Rebolo, R.; Amado, P. J. +40 more
Context. Small planets around low-mass stars often show orbital periods in a range that corresponds to the temperate zones of their host stars which are therefore of prime interest for planet searches. Surface phenomena such as spots and faculae create periodic signals in radial velocities and in observational activity tracers in the same range, s…
PG 1610+062: a runaway B star challenging classical ejection mechanisms
Geier, S.; Heber, U.; Irrgang, A. +2 more
Hypervelocity stars are rare objects, mostly main-sequence (MS) B stars, traveling so fast that they will eventually escape from the Milky Way. Recently, it has been shown that the popular Hills mechanism, in which a binary system is disrupted via a close encounter with the supermassive black hole at the Galactic center, may not be their only ejec…
Face changing companion of the redback millisecond pulsar PSR J1048+2339
Takata, J.; Kong, A. K. H.; Hui, C. Y. +3 more
We present optical observations of the redback millisecond pulsar PSR J1048+2339, which is a 4.66 ms radio pulsar in a compact binary with an orbital period of six hours. We obtained high-quality light curves of PSR J1048+2339 with the Lulin 1 m Telescope. The system shows two distinct six-hour orbital modulations, in which an ellipsoidal modulati…
Interpretation of heliocentric water production rates of comets
Attree, N.; Hartogh, P.; Rezac, L. +2 more
Aims: We investigate the influence of three basic factors on water production rate as a function of heliocentric distance: nucleus shape, the spin axis orientation, and the distribution of activity on a comet's surface.
Methods: We used a basic water sublimation model driven by solar insolation to derive total production rates for differ…