Search Publications
HD 51844: An Am δ Scuti in a binary showing periastron brightening
Baudin, F.; Poretti, E.; Michel, E. +12 more
Context. Pulsating stars in binary systems are ideal laboratories to test stellar evolution and pulsation theory, since a direct, model-independent determination of component masses is possible. The high-precision CoRoT photometry allows a detailed view of the frequency content of pulsating stars, enabling detection of patterns in their distributi…
Constraints on the winds of hot subdwarf stars from X-ray observations of two sdB binaries with compact companions: CD -30° 11223 and PG 1232-136
Tiengo, A.; Mereghetti, S.; Geier, S. +5 more
Little observational data are available on the weak stellar winds of hot subdwarf stars of B spectral type (sdB). Close binary systems composed of an sdB star and a compact object (white dwarf, neutron star or black hole) could be detected as accretion-powered X-ray sources. The study of their X-ray emission can probe the properties of line-driven…
A Chandra-HETG View of MCG +8-11-11
Nowak, M. A.; Murphy, K. D.
We present a spectral analysis of the 118 ks Chandra High Energy Transmission Gratings (HETG) observation of the X-ray bright Seyfert 1.5 galaxy MCG +8-11-11, in conjunction with 100 ks of archival Suzaku data, aimed at investigating the signatures of warm absorption and Compton reflection reported from previous Suzaku and XMM-Newton studies of th…
Herschel and Spitzer Observations of Slowly Rotating, Nearby Isolated Neutron Stars
Pavlov, G. G.; Wachter, S.; Posselt, B. +1 more
Supernova fallback disks around neutron stars have been suspected to influence the evolution of the diverse neutron star populations. Slowly rotating neutron stars are the most promising places to find such disks. Searching for the cold and warm debris of old fallback disks, we carried out Herschel PACS (70 µm, 160 µm) and Spitzer IRAC…
MIDACO software performance on interplanetary trajectory benchmarks
Schlueter, Martin
A numerical study of the MIDACO optimization software on the well known GTOP benchmark set, published by the European Space Agency (ESA), is presented. The GTOP database provides trajectory models of real-world interplanetary space missions such as Cassini, Messenger or Rosetta. The trajectory models are formulated as constrained nonlinear optimiz…
First spectrally-resolved H2 observations towards HH 54 . Low H2O abundance in shocks
Liseau, R.; Codella, C.; van Dishoeck, E. F. +11 more
Context. Herschel observations suggest that the H2O distribution in outflows from low-mass stars resembles the H2 emission. It is still unclear which of the different excitation components that characterise the mid- and near-IR H2 distribution is associated with H2O.
Aims: The aim is to spectrally r…
Radial distribution of magnetic field in earth magnetotail current sheet
Petrukovich, A. A.; Dunlop, M. W.; Baumjohann, W. +4 more
Knowing the magnetic field distribution in the magnetotail current sheet (CS) is essential for exploring magnetotail dynamics. In this study, using a joint dataset of Cluster/TC-1, the radial profile of the magnetic field in the magnetotail CS with radial distances covering 8<r<20RE under different geomagnetic activity states (i.e…
A non-LTE spectral analysis of the 3He and 4He isotopes in the HgMn star κ Cancri
Przybilla, Norbert; Maza, Natalia L.; Nieva, María-Fernanda
Aims: We present a pilot study on non-local thermodynamic equilibrium (NLTE) line-formation computations for the isotopes 3He and 4He in the mercury-manganese star κ Cancri. The impact of NLTE effects on the determination of isotopic abundances and the vertical stratification of helium in the atmosphere is investigated. …
Photometric investigation of the K-type extremely shallow contact binary V1799 Orion
Qian, Sheng-Bang; Liao, Wen-Ping; He, Jia-Jia +3 more
New multi-color light curves of the very short period K-type eclipsing binary V1799 Ori were obtained and analyzed with the Wilson-Devinney code. The photometric solutions reveal that the system is a W-type shallow-contact binary with a mass ratio of q = 1.335(±0.005) and a degree of contact of about f = 3.5(±1.1)%. In general, the results are in …
Stellar Encounter Driven Red-giant Star Mass Loss in Globular Clusters
Chung, Chul; Pasquato, Mario; Lee, Young-Wook +5 more
Globular cluster (GC) color-magnitude diagrams (CMDs) are reasonably well understood in terms of standard stellar evolution. However, there are still some open issues, such as fully accounting for the horizontal branch (HB) morphology in terms of chemical and dynamical parameters. Mass loss on the red giant branch (RGB) shapes the mass distributio…