Search Publications
Hard X-ray cataclysmic variables
Mukai, K.; de Martino, D.; Masetti, N. +2 more
Among hard X-ray Galactic sources detected with the Swift and INTEGRAL surveys, those discovered as accreting white dwarf binaries have surprisingly boosted in number in the recent years. The majority are identified as magnetic Cataclysmic Variables of the Intermediate Polar type, suggesting this subclass as an important constituent of the Galacti…
Radio observations of magnetic cataclysmic variables
Mason, Paul A.; Singh, Kulinder P.; Barrett, Paul +2 more
The NSF's Karl G. Jansky Very Large Array (VLA) is used to observe 122 magnetic cataclysmic variables (MCVs) during three observing semesters (13B, 15A, and 18A). We report radio detections of 33 stars with fluxes in the range 6-8031 µJy. Twenty-eight stars are new radio sources, increasing the number of radio detected MCVs to more that 40. …
On a century of extragalactic novae and the rise of the rapid recurrent novae
Darnley, Matthew J.; Henze, Martin
Novae are the observable outcome of a transient thermonuclear runaway on the surface of an accreting white dwarf in a close binary system. Their high peak luminosity renders them visible in galaxies out beyond the distance of the Virgo Cluster. Over the past century, surveys of extragalactic novae, particularly within the nearby Andromeda Galaxy, …
Large non-radial propagation of a coronal mass ejection on 2011 January 24
Mierla, M.; D'Huys, E.; Stenborg, G. +6 more
Understanding the deflection of coronal mass ejections (CMEs) is of great interest to the space weather community because of their implications for improving the prediction of CME. This paper aims to shed light into the effects of the coronal magnetic field environment on CME trajectories. We analyze the influence of the magnetic environment on th…
Two successive partial mini-filament confined ejections
Mandrini, C. H.; Cristiani, G. D.; López Fuentes, M. +2 more
Active region (AR) NOAA 11476 produced a series of confined plasma ejections, mostly accompanied by flares of X-ray class M, from 08 to 10 May 2012. The structure and evolution of the confined ejections resemble that of EUV surges; however, their origin is associated to the destabilization and eruption of a mini-filament, which lay along the photo…
Space debris observations with the Slovak AGO70 telescope: Astrometry and light curves
Šilha, Jiří; Krajčovič, Stanislav; Zigo, Matej +12 more
The Faculty of Mathematics, Physics and Informatics of Comenius University in Bratislava, Slovakia (FMPI) operates its own 0.7-m Newtonian telescope (AGO70) dedicated to the space surveillance tracking and research, with an emphasis on space debris. The observation planning focuses on objects on geosynchronous (GEO), eccentric (GTO and Molniya) an…
Cut-off features in interplanetary solar radio type IV emission
Pohjolainen, Silja; Talebpour Sheshvan, Nasrin
Solar radio type IV bursts can sometimes show directivity, so that no burst is observed when the source region in located far from the solar disk center. This has recently been verified also from space observations, at decameter wavelengths, using a 3D-view to the Sun with STEREO and Wind satellites. It is unclear whether the directivity is caused…
Analysis of a long-duration AR throughout five solar rotations: Magnetic properties and ejective events
Ugarte-Urra, Ignacio; Mandrini, Cristina H.; Cremades, Hebe +4 more
Coronal mass ejections (CMEs), which are among the most magnificent solar eruptions, are a major driver of space weather and can thus affect diverse human technologies. Different processes have been proposed to explain the initiation and release of CMEs from solar active regions (ARs), without reaching consensus on which is the predominant scenari…
Wavelet analysis of low frequency plasma oscillations in the magnetosheath of Mars
Fränz, M.; Bolzan, M. J. A.; Echer, E. +1 more
Wavelet analysis was employed to identify the major frequencies present in the plasma oscillations in the Martian magnetosheath. We have selected magnetosheath crossings and applied the Morlet wavelet transform to the electron density and temperature data, obtained from the Analyzer of Space Plasmas and Energetic Atoms experiment (ASPERA-3), onboa…
The complications of learning from Super Soft Source X-ray spectra
Ness, Jan-Uwe
Super Soft X-ray Sources (SSS) are powered by nuclear burning on the surface of an accreting white dwarf, they are seen around 0.1-1 keV (thus in the soft X-ray regime), depending on effective temperature and the amount of intervening interstellar neutral hydrogen (NH). The most realistic model to derive physical parameters from observe…