Search Publications
BO Ari Light Curve Analysis using Ground-Based and TESS Data
Poro, Atila; Rezaei, Samaneh; Aksaker, Nazim +4 more
We present new BVR band photometric light curves of BO Aries obtained in 2020 and combined them with the Transiting Exoplanet Survey Satellite (TESS) light curves. We obtained times of minima based on Gaussian and Cauchy distributions and then applied the Monte Carlo Markov Chain (MCMC) method to measure the amount of uncertainty from our CCD phot…
Mode identification and seismic study of δ Scuti, the prototype of a class of pulsating stars
Handler, G.; Pigulski, A.; Daszyńska-Daszkiewicz, J. +3 more
We present a seismic study of δ Scuti based on a mode identification from multicoulor photometry. The dominant frequency can be associated only with a radial mode and the second frequency is, most probably, a dipole mode. The other six frequencies have more ambiguous identifications. The photometric mode identification provided also some constrain…
Steepening of magnetosonic waves in the inner coma of comet 67P/Churyumov-Gerasimenko
Henri, Pierre; Goetz, Charlotte; Richter, Ingo +7 more
We present a statistical survey of large-amplitude, asymmetric plasma and magnetic field enhancements detected outside the diamagnetic cavity at comet 67P/Churyumov-Gerasimenko from December 2014 to June 2016. Based on the concurrent observations of plasma and magnetic field enhancements, we interpret them to be magnetosonic waves. The aim is to p…
Sampling Plume Deposits on Enceladus' Surface to Explore Ocean Materials and Search for Traces of Life or Biosignatures
Malaska, Michael J.; Choukroun, Mathieu; Backes, Paul +14 more
Enceladus is unique as an astrobiology target in that it hosts an active plume sourced directly from its habitable subsurface ocean. Ice particles from the plume contain geochemical constituents that are diagnostic of the ocean conditions, and may hold traces of life and/or biosignatures, if they exist. Up to 93% of the plume particles fall back o…
The hot interstellar medium towards 4U 1820-30: a Bayesian analysis
Waters, L. B. F. M.; Costantini, E.; Mehdipour, M. +3 more
Context. High-ionisation lines in the soft X-ray band are generally associated to either interstellar hot gas along the line of sight or to photoionised gas intrinsic to the source. In the low-mass X-ray binary 4U 1820-30, the nature of these lines is not well understood.
Aims: We aim to characterise the ionised gas present along the line of …
Forward Modeling of Simulated Transverse Oscillations in Coronal Loops and the Influence of Background Emission
Van Doorsselaere, Tom; Antolin, Patrick; Li, Bo +1 more
We simulate transverse oscillations in radiatively cooling coronal loops and forward-model their spectroscopic and imaging signatures, paying attention to the influence of background emission. The transverse oscillations are driven at one footpoint by a periodic velocity driver. A standing kink wave is subsequently formed and the loop cross sectio…
Estimating Teff, radius, and luminosity of M-dwarfs using high-resolution optical and NIR spectral features
Baug, Tapas; Mondal, Soumen; Das, Ramkrishna +1 more
We estimate effective temperature (Teff), stellar radius, and luminosity for a sample of 271 M-dwarf stars (M0V-M7V) observed as a part of CARMENES (Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle Spectrographs) radial-velocity planet survey. For the first time, using the simultaneou…
High-fidelity comet 67P ephemeris and predictions based on Rosetta data
Weryk, Robert; Farnocchia, Davide; Micheli, Marco +2 more
Because of observational biases and outgassing, comets are notoriously challenging in terms of trajectory estimation and ephemeris predictions. We used tracking data collected by ESA's Rosetta mission at 67P/Churyumov-Gerasimenko to derive 10-m level constraints on the distance between the Earth and 67P in 2014 and 2016, which, together with high-…
CO2 retrievals in the Mars daylight thermosphere from its 4.3 µm limb emission measured by OMEGA/MEx
Bibring, Jean-Pierre; Gondet, Brigitte; Funke, Bernd +6 more
We present a non-local thermodynamic equilibrium retrieval scheme for atmospheric composition and its application to Mars CO2 infrared limb emissions as measured by the OMEGA instrument on board Mars Express (MEx). These emissions are caused by CO2 fluorescence of solar radiation, and thus the retrieval scheme accounts for no…
Chemical evolution of the Galactic bulge as traced by microlensed dwarf and subgiant stars. VIII. Carbon and oxygen
Udalski, A.; Johnson, J. A.; Gould, A. +6 more
Context. Next to H and He, carbon is, together with oxygen, the most abundant element in the Universe and widely used when modelling the formation and evolution of galaxies and their stellar populations. For the Milky Way bulge, there are currently essentially no measurements of carbon in un-evolved stars, hampering our abilities to properly compa…