Search Publications
On the flux saturation of SOHO/ERNE proton events
Miteva, Rositsa; Dechev, Momchil; Samwel, Susan W. +1 more
This study lists the main procedures completed on the analysis of solar proton events using data from the SOHO/ERNE high energy detector in the period 1996$-$2017. The highest possible temporal resolution of 1 minute is used here. The proton fluxes from the two analyzed energy channels, at $\sim$25 and $\sim$50 MeV, are compared with the respectiv…
Bright spectroscopic binaries: I. Orbital parameters of five systems with periods of P < 365 days
Jack, Dennis; Schröder, Klaus-Peter; Hernández Huerta, Missael Alejandro
In a well‑aimed search based on the recently published Gaia DR2 radial velocity data and performed with the robotic TIGRE telescope, we have discovered 19 bright (mV < 7.66 mag) spectroscopic binary stars. We present the radial velocity curves of five of these stars (HD 20656, HD 27259, HD 98812, HD 150600, HD 193082) with periods of P < 365…
Identification of young nearby runaway stars based on Gaia data and the lithium test†
Torres, Guillermo; Mugrauer, Markus; Lux, Oliver +6 more
Young nearby runaway stars are suitable to search for their place of origin and possibly associated objects, for example, neutron stars. Tetzlaff et al. (2011) selected young (≤50 Myr) runaway star candidates from Hipparcos, for which they had estimated the ages from the location in the Hertzsprung-Russell diagram and evolutionary models. Here, we…
X-Ray Observations of the Peculiar Cepheid V473 Lyr Identify A Low-mass Companion
Drake, Jeremy J.; Evans, Nancy Remage; Marengo, Massimo +17 more
V473 Lyr is a classical Cepheid that is unique in having substantial amplitude variations with a period of approximately 3.3 yr, thought to be similar to the Blazhko variations in RR Lyrae stars. We obtained an XMM-Newton observation of this star to follow up a previous detection in X-rays. Rather than the X-ray burst and rapid decline near maximu…
Dust and gas in the central region of NGC 1316 (Fornax A). Its origin and nature
Hilker, M.; Richtler, T.; Iodice, E.
Context. The early-type galaxy NGC 1316, associated with the radio source Fornax A, hosts about 107 M⊙ of dust within a central radius of 5 kpc. These prominent dust structures are believed to have an external origin, which is also a popular interpretation for other dusty early-type galaxies. Moreover, it has been long known …
First speckle interferometric measurements of binary stars at the Observatorio Astrofísico Guillermo Haro
Guerrero, C. A.; Castillo, E.; Rosales-Ortega, F. F. +4 more
In this paper, we present the first multiband speckle interferometric measurements of binary stars performed using the 2.1 m telescope of the Observatorio Astrofísico Guillermo Haro, Cananea, Sonora, México. We describe here FICCO: Fast Imaging Camera for Cananea Observatory, a new instrument developed to perform speckle observations from the Nort…
Analyzing the propagation of EUV waves and their connection with type II radio bursts by combining numerical simulations and multi-instrument observations
Dolla, L.; Downs, C.; Marqué, C. +1 more
Context. EUV (EIT) waves are wavelike disturbances of enhanced extreme ultraviolet (EUV) emission that propagate away from an eruptive active region across the solar disk. Recent years have seen much debate over their nature, with three main interpretations: the fast-mode magneto-hydrodynamic (MHD) wave, the apparent wave (reconfiguration of the m…
Recurrent Solar Energetic Particle Flux Enhancements Observed near Earth and Mars
Bhardwaj, Anil; Lee, Christina O.; Thampi, Smitha V. +3 more
The period 2016 August 1 to November 15 was characterized by the presence of corotating interaction regions (CIRs) and a few weak coronal mass ejections (CMEs) in the heliosphere. In this study we show recurrent energetic electron and proton enhancements observed near Earth (1 au) and Mars (1.43-1.38 au) during this period. The observations near E…
The Coronal Mass Ejection Visibility Function of Modern Coronagraphs
St. Cyr, O. C.; Vourlidas, Angelos; Xie, H. +1 more
We analyze the detection capability of coronal mass ejections (CMEs) for all currently operating coronagraphs in space. We define as CMEs events that propagate beyond 10 solar radii with morphologies broadly consistent with a magnetic flux-rope presence. We take advantage of multi-viewpoint observations over five month-long intervals, correspondin…
Kinematic distinction of the two subpopulations of X-ray pulsars
Prišegen, M.
Context. The population of Be/X-ray binaries shows strong evidence of bimodality, especially in the spin period of neutron stars. Several physical mechanisms may produce this bimodality. The most favored candidate mechanisms are two distinct supernova channels or different accretion modes of the neutron stars in Be/X-ray binaries. Investigating th…