Search Publications
VVV-WIT-08: the giant star that blinked
Smith, Leigh C.; Udalski, Andrzej; Minniti, Dante +11 more
We report the serendipitous discovery of a late-type giant star that exhibited a smooth, eclipse-like drop in flux to a depth of 97 per cent. Minimum flux occurred in 2012 April and the total event duration was a few hundred days. Light curves in V, I, and Ks from the Optical Gravitational Lensing Experiment and VISTA Variables in the V…
Electron Densities in the Solar Corona Measured Simultaneously in the Extreme Ultraviolet and Infrared
Del Zanna, Giulio; Dudík, Jaroslav; Dzifčáková, Elena +5 more
Accurate measurements of electron density are critical for determination of the plasma properties in the solar corona. We compare the electron densities diagnosed from Fe XIII lines observed by the Extreme-Ultraviolet Imaging Spectrometer (EIS) onboard the Hinode mission with the near-infrared (NIR) measurements provided by the ground-based Corona…
The Center of Expansion and Age of the Oxygen-rich Supernova Remnant 1E 0102.2-7219
Drout, Maria R.; Blair, William P.; Margutti, Raffaella +8 more
We present new proper-motion measurements of optically emitting oxygen-rich knots of supernova remnant 1E 0102.2-7219 (E0102), which are used to estimate the remnant's center of expansion and age. Four epochs of high-resolution Hubble Space Telescope images spanning 19 yr were retrieved and analyzed. We found a robust center of expansion of α = 1<…
BepiColombo's cruise phase: unique opportunity for synergistic observations
André, N.; Escoubet, C. P.; Müller, D. +31 more
The investigation of multi-spacecraft coordinated observations during the cruise phase of BepiColombo (ESA/JAXA) are reported, with a particular emphasis on the recently launched missions, Solar Orbiter (ESA/NASA) and Parker Solar Probe (NASA). Despite some payload constraints, many instruments onboard BepiColombo are operating during its cruise p…
VLA Measurements of Faraday Rotation Through a Coronal Mass Ejection Using Multiple Lines of Sight
Ascione, Madison L.; Kooi, Jason E.; Ashas, Mohammad +2 more
Coronal mass ejections (CMEs) are large eruptions of magnetized plasma from the Sun that play an important role in space weather. The key to understanding the fundamental physics of a CME is measurement of the plasma properties within heliocentric distances of <20 R⊙. Faraday rotation, a radioastronomical propagation measurement, is …
Combining magneto-hydrostatic constraints with Stokes profiles inversions. II. Application to Hinode/SP observations
Pastor Yabar, A.; Ruiz Cobo, B.; Borrero, J. M.
Context. Inversion techniques applied to the radiative transfer equation for polarized light are capable of inferring the physical parameters in the solar atmosphere (temperature T, magnetic field B, and line-of-sight velocity vlos) from observations of the Stokes vector (i.e., spectropolarimetric observations) in spectral lines. Infere…
Warm protons at comet 67P/Churyumov-Gerasimenko - implications for the infant bow shock
Nilsson, Hans; Goetz, Charlotte; Gunell, Herbert +4 more
The plasma around comet 67P/Churyumov-Gerasimenko showed remarkable variability throughout the entire Rosetta mission. Plasma boundaries such as the diamagnetic cavity, solar wind ion cavity and infant bow shock separate regions with distinct plasma parameters from each other. Here, we focus on a particular feature in the plasma: warm, slow solar …
Microwave diagnostics of magnetic field strengths in solar flaring loops
Tian, Hui; Zhu, Rui; Xu, Yu +5 more
We have performed microwave diagnostics of the magnetic field strengths in solar flare loops based on the theory of gyrosynchrotron emission. From Nobeyama Radioheliograph observations of three flare events at 17 and 34 GHz, we obtained the degree of circular polarization and the spectral index of microwave flux density, which were then used to ma…
The Hubble PanCET program: long-term chromospheric evolution and flaring activity of the M dwarf host GJ 3470
Sanz-Forcada, J.; Ehrenreich, D.; Bourrier, V. +9 more
Neptune-size exoplanets seem particularly sensitive to atmospheric evaporation, making it essential to characterize the stellar high-energy radiation that drives this mechanism. This is particularly important with M dwarfs, which emit a large and variable fraction of their luminosity in the ultraviolet and can display strong flaring behavior. The …
SuperWASP variable stars: classifying light curves using citizen science
Thiemann, Heidi B.; Norton, Andrew J.; Kolb, Ulrich C. +2 more
We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains >1 millio…