Search Publications
Two short mass-loss events that unveil the binary heart of Minkowski's Butterfly Nebula
Bachiller, R.; Chesneau, O.; Bujarrabal, V. +3 more
Context. Studying the appearance and properties of bipolar winds is critical to understand the stellar evolution from the AGB to the planetary nebula (PN) phase. Many uncertainties exist regarding the presence and role of binary stellar systems, mainly due to the deficit of conclusive observational evidences.
Aims: We investigate the extended…
Lagrangian coherent structures in photospheric flows and their implications for coronal magnetic structure
Yeates, A. R.; Welsch, B. T.; Hornig, G.
Aims: We show how the build-up of magnetic gradients in the Sun's corona may be inferred directly from photospheric velocity data. This enables computation of magnetic connectivity measures such as the squashing factor without recourse to magnetic field extrapolation.
Methods: Assuming an ideal evolution in the corona, and an initially u…
Galactic annihilation emission from nucleosynthesis positrons
Strong, A. W.; Diehl, R.; Jean, P. +2 more
Context. The Galaxy hosts a widespread population of low-energy positrons revealed by successive generations of gamma-ray telescopes through a bright annihilation emission from the bulge region, with a fainter contribution from the inner disk. The exact origin of these particles remains currently unknown.
Aims: We estimate the contribution to…
Detection of multiple modes in a new double-mode RR Lyrae star
Chadid, M.
Context. We present the first long-time coverage of high precision and uninterrupted light curve of a new double-mode RR Lyrae star allowing the determination of accurate Fourier components and the estimatation of fundamental parameters.
Aims: We used high-precision space data of a new star CoRoT ID 0101368812, obtained by the satellite CoRoT…
X-ray emitting hot plasma in solar active regions observed by the SphinX spectrometer
Miceli, M.; Reale, F.; Sylwester, J. +7 more
Aims: The detection of very hot plasma in the quiescent corona is important for diagnosing heating mechanisms. The presence and the amount of such hot plasma is currently debated. The SphinX instrument on-board the CORONAS-PHOTON mission is sensitive to X-ray emission of energies well above 1 keV and provides the opportunity to detect the hot…
The very low mass multiple system LHS 1070. A testbed for model atmospheres for the lower end of the main sequence
Schultheis, M.; Ryde, N.; Leinert, Ch. +8 more
Context. LHS 1070 is a nearby multiple system of low mass stars. It is an important source of information for probing the low mass end of the main sequence, down to the hydrogen-burning limit. The primary of the system is a mid-M dwarf and two components are late-M to early L dwarfs, at the star-brown dwarf transition. Hence LHS 1070 is a valuable…
Calibrating the projection factor for Galactic Cepheids
Marengo, M.; Nardetto, N.; Ngeow, C. -C. +1 more
Context. The projection factor (p), which converts the radial velocity to pulsational velocity, is an important parameter in the Baade-Wesselink (BW) type analysis and distance scale work. The p-factor is either adopted as a constant or linearly depending on the logarithmic of pulsating periods.
Aims: The aim of this work is to calibrate the …
XMM-Newton observations of four high mass X-ray binaries and IGR J17348-2045
Campana, S.; Stella, L.; Paltani, S. +5 more
We present the results of the XMM-Newton observations of five hard X-ray emitters: IGR J08262-3736, IGR J17354-3255, IGR J16328-4726, SAX J1818.6-1703, and IGR J17348-2045. The first source is a confirmed supergiant high mass X-ray binary, the following two are candidates supergiant fast X-ray transients, SAX J1818.6-1703 is a confirmed supergiant…
The ancient stellar population of M 32: RR Lyrae variable stars confirmed
Saha, A.; Clementini, G.; Contreras Ramos, R. +2 more
Using archival multi-epoch ACS/WFC images in the F606W and F814W filters of a resolved stellar field in Local Group dwarf elliptical galaxy M 32 we have made an accurate colour-magnitude diagram and a careful search for RR Lyr variable stars. We identified 416 bona fide RR Lyr stars over our field of view, and their spatial distribution shows a ri…
The horizontal branch luminosity vs. metallicity in M 31 globular clusters
Cacciari, C.; Bellazzini, M.; Galleti, S. +3 more
Context. Thanks to the outstanding capabilites of the HST, our current knowledge about the M 31 globular clusters (GCs) is similar to our knowledge of the Milky Way GCs in the 1960s - 1970s, which set the basis for studying the halo and galaxy formation using these objects as tracers, and established their importance in defining the cosmic distanc…