Search Publications
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…
DustPedia: the relationships between stars, gas, and dust for galaxies residing in different environments
Bianchi, S.; Fritz, J.; Madden, S. C. +20 more
We use a sub-set of the DustPedia galaxy sample (461 galaxies) to investigate the effect the environment has had on galaxies. We consider Virgo cluster and field samples and also assign a density contrast parameter to each galaxy, as defined by the local density of SDSS galaxies. We consider their chemical evolution (using MDust/MB…
The fate of the interstellar medium in early-type galaxies. I. First direct measurement of the timescale of dust removal
Frayer, D. T.; Michałowski, M. J.; Hughes, D. H. +12 more
Context. An important aspect of quenching star formation is the removal of the cold interstellar medium (ISM; non-ionised gas and dust) from a galaxy. In addition, dust grains can be destroyed in a hot or turbulent medium. The adopted timescale of dust removal usually relies on uncertain theoretical estimates. It is tricky to track dust removal be…
GIARPS High-resolution Observations of T Tauri stars (GHOsT). I. Jet line emission
Munari, U.; Bacciotti, F.; Fedele, D. +9 more
Context. The mechanism for jet formation in the disks of T Tauri stars remains poorly understood. Observational benchmarks to launching models can be provided by tracing the physical properties of the kinematic components of the wind and jet in the inner 100 au of the disk surface.
Aims: In the framework of the GIARPS High-resolution Observat…
Probing the weak wind phenomenon in Galactic O-type giants
Bouret, J. -C.; Pereira, C. B.; Marcolino, W. L. F. +1 more
Aims: Analyses of Galactic late O dwarfs (O8-O9.5V stars) raised the "weak wind problem": spectroscopic mass-loss rates (Ṁ) are up to two orders of magnitude lower than the theoretical values. We investigated the stellar and wind properties of Galactic late O giants (O8-O9.5III stars). These stars have luminosities log (L⋆ / L…
Transit Lyman-α signatures of terrestrial planets in the habitable zones of M dwarfs
Holmström, M.; Lammer, H.; Güdel, M. +6 more
Aims: We modeled the transit signatures in the Lyman-alpha (Ly-α) line of a putative Earth-sized planet orbiting in the habitable zone (HZ) of the M dwarf GJ 436. We estimated the transit depth in the Ly-α line for an exo-Earth with three types of atmospheres: a hydrogen-dominated atmosphere, a nitrogen-dominated atmosphere, and a nitrogen-do…
Launch of a CME-associated eruptive prominence as observed with IRIS and ancillary instruments
Vial, J. -C.; Zhang, P.; Buchlin, É.
Aims: In this paper we focus on the possible observational signatures of the processes which have been put forward for explaining eruptive prominences. We also try to understand the variations in the physical conditions of eruptive prominences and estimate the masses leaving the Sun versus the masses returning to the Sun during eruptive promi…