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First analysis of eight Algol-type binaries: EI Aur, XY Dra, BP Dra, DD Her, VX Lac, WX Lib, RZ Lyn, and TY Tri
Zasche, P.
The available photometry from the online databases were used for the first light curve analysis of eight eclipsing binary systems EI Aur, XY Dra, BP Dra, DD Her, VX Lac, WX Lib, RZ Lyn, and TY Tri. All these stars are of Algol-type, having the detached components and the orbital periods from 0.92 to 6.8 days. For the systems EI Aur and BP Dra the …
Some properties of field-aligned electron events in high-altitude polar regions
Zhang, ZiYing; Shi, JianKui; Zhou, MingQuan +2 more
Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron (FAE) events and interplanetary magnetic field (IMF) By dependence of FAE events with different durations in high-altitude polar regions. A total of 1335 FAE events were observed by the C3 space…
Milky Way mapper: 6 ways the Gaia spacecraft will change astronomy
Castelvecchi, Davide
European mission will shed light on hidden asteroids, the Universe’s expansion and exoplanets.
Dusty Quasars at High Redshifts
Weedman, Daniel; Sargsyan, Lusine
A population of quasars at z ∼ 2 is determined based on dust luminosities νL ν (7.8 µm) that includes unobscured, partially obscured, and obscured quasars. Quasars are classified by the ratio νL ν (0.25 µm)/νL ν (7.8 µm) = UV/IR, assumed to measure obscuration of UV luminosity by the dust that …
Hubble imaging of V1331 Cygni: proper motion study of its circumstellar structures
Stecklum, B.; Linz, Hendrik; Choudhary, A.
Aims: The young star V1331 Cyg received previous attention because it is surrounded by an optical, arc-like reflection nebula. V1331 Cyg is commonly considered to be a candidate for an object that has undergone an FU-Ori (FUOR) outbreak in the past. This in turn could lead to a time-varying appearance of the dusty arcs that may be revealed by…
New visions of spectroscopic databases: An introduction to the special issue
Vander Auwera, J.; Flaud, Jean-Marie; Jacquinet-Husson, Nicole +2 more
Searching for Faraday rotation in cosmic microwave background polarization
Battaner, E.; Ruiz-Granados, B.; Florido, E.
We use the Wilkinson Microwave Anisotropy Probe (WMAP) 9th-year foreground reduced data at 33, 41 and 61 GHz to derive a Faraday rotation at map and at angular power spectrum levels taking into account their observational errors. A processing mask provided by WMAP is used to avoid contamination from the disc of our Galaxy and local spurs. We have …
Doppler Shift of the Quiet Region Measured by Meridional Scans with the EUV Imaging Spectrometer on board Hinode
Hara, H.; Kitagawa, N.; Yokoyama, T.
Spatially averaged (> 50") EUV spectral lines in the transition region of solar quiet regions are known to be redshifted. Because the mechanism underlying this phenomenon is unclear, we require additional physical information on the lower corona in order to limit the theoretical models. To acquire this information, we measured the Doppler shift…
Variability of the X-ray broad iron spectral features in active galactic nuclei and black-hole binaries
Tsujimoto, M.; Ebisawa, K.; Inoue, H. +1 more
The ``broad iron spectral features'' are often seen in X-ray spectra of active galactic nuclei (AGN) and black-hole binaries (BHB). These features may be explained either by the ``relativistic disc reflection'' scenario or the ``partial covering'' scenario: It is hardly possible to determine which model is valid from time-averaged spectral analysi…
The end-of-life disposal of satellites in libration-point orbits using solar radiation pressure
Soldini, Stefania; Colombo, Camilla; Walker, Scott
This paper proposes an end-of-life propellant-free disposal strategy for libration-point orbits which uses solar radiation pressure to restrict the evolution of the spacecraft motion. The spacecraft is initially disposed into the unstable manifold leaving the libration-point orbit, before a reflective sun-pointing surface is deployed to enhance th…