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A photometric study of chemically peculiar stars with the STEREO satellites - II. Non-magnetic chemically peculiar stars
White, G. J.; Fossati, L.; Paunzen, E. +3 more
We have analysed the photometric data obtained with the STEREO spacecraft for 558 non-magnetic chemically peculiar (CP) stars to search for rotational and pulsational variability. Applying the Lomb-Scargle and the phase dispersion minimization methods, we have detected photometric variability for 44 objects from which 35 were previously unknown. T…
A multi-wavelength view of AB Doradus outer atmosphere . Simultaneous X-ray and optical spectroscopy at high cadence
Wieringa, M. H.; Schmitt, J. H. M. M.; Wolter, U. +3 more
Aims: We study the chromosphere and corona of the ultra-fast rotator
X-Ray Measurement of the Spin-down of Calvera: A Radio- and Gamma-Ray-Quiet Pulsar
Gotthelf, E. V.; Halpern, J. P.; Bogdanov, S.
We measure spin-down of the 59 ms X-ray pulsar Calvera by comparing the XMM-Newton discovery data from 2009 with new Chandra timing observations taken in 2013. Its period derivative is \dot{P}=(3.19+/- \,0.08)\times 10^{-15}, which corresponds to spin-down luminosity \dot{E}=6.1\times 10^{35} erg s-1, characteristic age \tau _c\equiv P/…
The Top 10 Spitzer Young Stellar Objects in 30 Doradus
Walborn, Nolan R.; Barbá, Rodolfo H.; Sewiło, Marta M.
The most luminous Spitzer point sources in the 30 Doradus triggered second generation are investigated coherently in the 3-8 µm region. Remarkable diversity and complexity in their natures are revealed. Some are also among the brightest JHK sources, while others are not. Several of them are multiple when examined at higher angular resolution…
Thomson scattering and collisional ionization in the X-ray grating spectra of the recurrent nova U Scorpii
Nelson, T.; Luna, G. J. M.; Rauch, T. +7 more
We present a Chandra observation of the recurrent nova U Scorpii, done with the High Resolution camera-S (HRC-S) detector and the Low Energy Transmission Grating (LETG) on day 18 after the observed visual maximum of 2010, and compare it with XMM-Newton observations obtained on days 23 and 35 after maximum. The total absorbed flux was in the range …
Structure of Titan's induced magnetosphere under varying background magnetic field conditions: Survey of Cassini magnetometer data from flybys TA-T85
Dougherty, Michele K.; Saur, Joachim; Simon, Sven +4 more
Cassini magnetic field observations between 2004 and 2012 suggest the ambient field conditions near Titan's orbit to differ significantly from the frequently applied pre-Cassini picture (background magnetic field homogeneous and perpendicular to Titan's orbital plane, stationary upstream conditions). In this study, we analyze the impact of these v…
Optical and X-Ray Studies of 10 X-Ray-selected Cataclysmic Binaries
Thorstensen, John R.; Halpern, Jules
We report on ground-based optical observations of 10 cataclysmic binaries that were discovered through their X-ray emission. Time-resolved radial velocity spectroscopy yields unambiguous orbital periods for eight objects and ambiguous results for the remaining two. The orbital periods range from 87 minutes to 9.38 hr. We also obtained time-series …
The Radial Distribution of Water Ice and Chromophores across Saturn's System
Brown, R. H.; Buratti, B. J.; Clark, R. N. +11 more
Over the past eight years, the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini orbiter has returned hyperspectral images in the 0.35-5.1 µm range of the icy satellites and rings of Saturn. These very different objects show significant variations in surface composition, roughness, and regolith grain size as a result of th…
Hydrogen Chloride in Diffuse Interstellar Clouds along the Line of Sight to W31C (G10.6-0.4)
Godard, B.; Roueff, E.; Lis, D. C. +5 more
We report the detection of hydrogen chloride, HCl, in diffuse molecular clouds on the line of sight toward the star-forming region W31C (G10.6-0.4). The J = 1-0 lines of the two stable HCl isotopologues, H35Cl and H37Cl, are observed using the 1b receiver of the Heterodyne Instrument for the Far-Infrared (HIFI) on board the H…
What do the Mt. Wilson stars tell us about solar activity?
Schmitt, J. H. M. M.; Schröder, K. -P.; Mittag, M. +2 more
We relate the evolutionary status and mass of the Mt. Wilson project stars with the type and strength of stellar activity as established in decades of monitoring their chromospheric Ca II K line emission. We specifically derive their positions in the Hertzsprung-Russell-diagram (HRD) from Hipparcos parallaxes and SIMBAD B - V data, considering and…