Search Publications
Chandra-HETGS Characterization of an Outflowing Wind in the Accreting Millisecond Pulsar IGR J17591-2342
Wilms, Jörn; Chenevez, Jérôme; Rodriguez, Jérôme +5 more
An accreting millisecond X-ray pulsar, IGR J17591-2342 was discovered in 2018 August in scans of the Galactic bulge and center by the International Gamma-Ray Astrophysics Laboratory X-ray and gamma-ray observatory. It exhibited an unusual outburst profile with multiple peaks in the X-ray, as observed by several X-ray satellites over 3 months. Here…
Dust-depletion sequences in damped Lyman-α absorbers. II. The composition of cosmic dust, from low-metallicity systems to the Galaxy
Petitjean, Patrick; De Cia, Annalisa; Andersen, Anja C. +1 more
Metals in the interstellar medium (ISM) of essentially all types of galaxies are observed to be depleted compared to the expected values. The depletion is most likely due to dust condensation in, for example, cold molecular clouds and various circumstellar and interstellar environments. The relative observed metal abundances should thereby reflect…
K2-291b: A Rocky Super-Earth in a 2.2 day Orbit
Vanderburg, Andrew; López-Morales, Mercedes; Latham, David W. +43 more
K2-291 is a solar-type star with a radius of R * = 0.899 ± 0.034 R ⊙ and mass of M* = 0.934 ± 0.038 M ⊙. From the K2 C13 data, we found one super-Earth planet (R p = {1.589}-0.072+0.095 R ⊕) transiting this star on a short period orbit (P = {2.225177}-6.…
Is there a fundamental upper limit to the mass of a star cluster?
Leaman, Ryan; Schinnerer, Eva; van de Ven, Glenn +2 more
The discovery around the turn of the millennium of a population of very massive (M⋆ > 2 × 106 M⊙) compact stellar systems (CSS) with physical properties (radius, velocity dispersion, stellar mass etc.) that are intermediate between those of the classical globular cluster (GC) population and galaxies led to quest…
Ultraviolet and optical spectroscopy of AGB stars showing UV excess
Guerrero, Martín A.; Ortiz, Roberto; Costa, Roberto D. D.
We have examined ultraviolet (UV) and optical UB spectra of 20 UV-emitting Asymptotic Giant Branch (AGB) stars of various variability classes to study the intensity of the continuum and emission lines as a function of stellar visual magnitude to shed light on the origin of their UV emission. A significant fraction (60 per cent) of these stars show…
Asteroseismic modelling of the subgiant µ Herculis using SONG data: lifting the degeneracy between age and model input parameters
Bedding, Timothy R.; Stello, Dennis; Deng, Licai +3 more
We model the oscillations of the SONG target µ Herculis to estimate the parameters of the star. The ℓ = 1 mixed modes of µ Her provide strong constraints on stellar properties. The mass and age given by our asteroseismic modelling are 1.10^{+0.11}_{-0.06} M⊙ and 7.55^{+0.96}_{-0.79} Gyr, respectively. The initial helium abun…
Strategic Planning Insights for Future Science-Driven Extravehicular Activity on Mars
Brady, Allyson L.; Kobs Nawotniak, Shannon E.; Hughes, Scott S. +8 more
Short-term and long-term science plans were developed as part of the strategic planning process used by the Biologic Analog Science Associated with Lava Terrains (BASALT) science team to conduct two Mars-simulation missions investigating basalt habitability at terrestrial volcanic analog sites in 2016. A multidisciplinary team of scientists genera…
The CARMENES search for exoplanets around M dwarfs. Detection of a mini-Neptune around LSPM J2116+0234 and refinement of orbital parameters of a super-Earth around GJ 686 (BD+18 3421)
Schmitt, J. H. M. M.; Amado, P. J.; Bauer, F. F. +34 more
Although M dwarfs are known for high levels of stellar activity, they are ideal targets for the search of low-mass exoplanets with the radial velocity (RV) method. We report the discovery of a planetary-mass companion around LSPM J2116+0234 (M3.0 V) and confirm the existence of a planet orbiting GJ 686 (BD+18 3421; M1.0 V). The discovery of the pl…
Density Fluctuations in the Lower Thermosphere of Mars Retrieved From the ExoMars Trace Gas Orbiter (TGO) Aerobraking
Medvedev, Alexander S.; Hartogh, Paul; Yiğit, Erdal +2 more
The upper atmosphere of Mars is constantly perturbed by small-scale gravity waves propagating from below. As gravity waves strongly affect the large-scale dynamics and thermal state, constraining their statistical characteristics is of great importance for modeling the atmospheric circulation. We present a new data set of density perturbation ampl…
The Martian daytime convective boundary layer: Results from radio occultation measurements and a mesoscale model
Pätzold, M.; Hinson, D. P.; Häusler, B. +4 more
We investigate the behavior of the Martian daytime convective boundary layer (CBL) through a combination of data analysis and modeling. This study relies on two subsets of Mars Express radio occultation (RO) measurements that sounded the atmosphere in northern spring of successive Mars years. Only the first year of observations has been examined p…