Search Publications
Overall properties of the Gaia DR1 reference frame
Liu, N.; Zhu, Z.; Liu, J. -C. +1 more
Aims: The first Gaia data release (Gaia DR1) provides 2191 ICRF2 sources with their positions in the auxiliary quasar solution and five astrometric parameters - positions, parallaxes, and proper motions - for stars in common between the Tycho-2 catalogue and Gaia in the joint Tycho-Gaia astrometric solution (TGAS). We aim to analyze the overa…
The calibration of read-out-streak photometry in the XMM-Newton Optical Monitor and the construction of a bright-source catalogue
Carter, M.; Talavera, A.; Page, M. J. +7 more
The dynamic range of the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded from its micro-channel-plate (MCP) intensified charge-coupled device (CCD) detector. One way to overcome this limitation is to use photons that arrive during the fram…
Disrupted Asteroid P/2016 G1. II. Follow-up Observations from the Hubble Space Telescope
Moreno, F.; Pinilla-Alonso, N.; Licandro, J. +3 more
After the early observations of the disrupted asteroid P/2016 G1 with the 10.4 m Gran Telescopio Canarias (GTC) and modeling of the dust ejecta, we have performed a follow-up observational campaign of this object using the Hubble Space Telescope (HST) during two epochs (2016 June 28 and July 11). The analysis of these HST images with the same mode…
Astronomical imaging with the X-ray observatory Hitomi
Nakajima, Hiroshi; Hitomi Collaboration
We report an imaging capability of the Japan-led X-ray observatory Hitomi, formerly known as ASTRO-H. It carries four scientific instruments of Soft X-ray Imager (SXI: CCD camera), Hard X-ray Imager (HXI), Soft X-ray Spectrometer, and Soft Gamma-ray Detector, allowing us to perform a wide-band high-sensitive imaging spectroscopy. We highlight the …
Measurement of Solar Neutrons on 05 March 2012, Using a Fiber-Type Neutron Monitor Onboard the Attached Payload to the ISS
Masuda, S.; Muraki, Y.; Kawano, H. +3 more
The solar neutron detector Space Environment Data Acquisition Equipment - Attached Payload (SEDA-FIB) onboard the International Space Station (ISS) detected several events from the solar direction associated with three large solar flares observed on 05 (X1.1), 07 (X5.4), and 09 (M6.3) March 2012. In this study, we focus on the interesting event of…
Temporal Variations in Solar Irradiance Since 1947
Tebabal, A.; Damtie, B.; Nigussie, M. +1 more
The study of variations in total solar irradiance (TSI) and spectral irradiance is important for understanding how the Sun affects the Earth's climate. A data-driven approach is used in this article to analyze and model the temporal variation of the TSI and Mg II index back to 1947. In both cases, observed data in the time interval of the satellit…
Reconstruction of the flight and attitude of Rosetta's lander Philae
Richter, Ingo; Auster, Hans-Ulrich; Heinisch, Philip +14 more
Since Rosetta's lander Philae touched down on comet 67P/Churyumov-Gerasimenko on November 12, 2014, many tools have been applied to reconstruct Philae's flight path and attitude between separation, the touchdowns, collision and the final landing at Abydos. In addition to images from the cameras onboard both orbiter and lander (;OSIRIS;, ;CIVA; and…
Detecting periodic oscillations in astronomy data: revisiting wavelet analysis with coloured and white noise
Xu, Chang
The intrinsic random variability of an astronomical source hampers the detection of possible periodicities that we are interested in. We find that a simple first-order autoregressive [AR(1)] process gives a poor fit to the power decay in the observed spectrum for astrophysical sources and geodetic observations. Thus, appropriate background noise m…
Validation of the CME Geomagnetic Forecast Alerts Under the COMESEP Alert System
Dumbović, Mateja; Vršnak, Bojan; Rao, Yamini K. +3 more
Under the European Union 7th Framework Programme (EU FP7) project Coronal Mass Ejections and Solar Energetic Particles (COMESEP, http://comesep.aeronomy.be), an automated space weather alert system has been developed to forecast solar energetic particles (SEP) and coronal mass ejection (CME) risk levels at Earth. The COMESEP alert system uses the …
Catalogue of Astrometric Positions of Jupiter's Outer Satellites on Photographic Observations in Mao NAS of Ukraine in 1987-1993
Yizhakevych, O.; Andruk, V.; Pakuliak, L.
The catalog of 33 topocentric positions of Jupiter's moons J6, J7, J8 has been created on photographic observations made in MAO NASU in 1987-1993. Positions are referred to the system of TYCHO-2 using the program package INUX/MIDAS/ROMAFOT. The comparison of observed positions was made online with their theoretical data of IMCCE (www.imcce.fr/sat).