Search Publications
Jovian High-Latitude Ionospheric Ions: Juno In Situ Observations
Thomsen, M. F.; Wilson, R. J.; Louarn, P. +10 more
The low-altitude, high-velocity trajectory of the Juno spacecraft enables the Jovian Auroral Distributions Experiment to make the first in situ observations of the high-latitude ionospheric plasma. Ions are observed to energies below 1 eV. The high-latitude ionospheric ions are observed simultaneously with a loss cone in the magnetospheric ions, s…
A New Automatic Tool for CME Detection and Tracking with Machine-learning Techniques
Zhang, Yan; Feng, Li; Lu, Lei +7 more
With the accumulation of coronal mass ejection (CME) observations by coronagraphs, automatic detection and tracking of CMEs has proven to be crucial. The excellent performance of the convolutional neural network in image classification, object detection, and other computer vision tasks motivates us to apply it to CME detection and tracking as well…
Discovery of a directly imaged disk in scattered light around the Sco-Cen member Wray 15-788
Ginski, C.; Benisty, M.; de Boer, J. +10 more
Context. Protoplanetary disks are the birth environments of planetary systems. Therefore, the study of young, circumstellar environments is essential in understanding the processes taking place in planet formation and the evolution of planetary systems.
Aims: We detect and characterize circumstellar disks and potential companions around solar…
Coronal Imaging with the Solar UltraViolet Imager
Seaton, Daniel B.; Tadikonda, Sivakumara K.; Krimchansky, Alexander +3 more
We investigate the coronal imaging capabilities of the Solar UltraViolet Imager (SUVI) on board the Geostationary Operational Environmental Satellite-R series spacecraft. Nominally Sun-pointed, SUVI provides solar images in six extreme ultraviolet (EUV) wavelengths. On-orbit data indicated that SUVI had sufficient dynamic range and sensitivity to …
Machine-learning identification of asteroid groups
Carruba, V.; Aljbaae, S.; Lucchini, A.
Asteroid families are groups of asteroids that share a common origin. They can be the outcome of a collision or be the result of the rotational failure of a parent body or its satellites. Collisional asteroid families have been identified for several decades using hierarchical clustering methods (HCMs) in proper elements domains. In this method, t…
Nitrogen-containing Anions and Tholin Growth in Titan’s Ionosphere: Implications for Cassini CAPS-ELS Observations
Coates, Andrew J.; Carrasco, Nathalie; Desai, Ravindra T. +4 more
The Cassini Plasma Spectrometer (CAPS) Electron Spectrometer (ELS) instrument on board Cassini revealed an unexpected abundance of negative ions above 950 km in Titan’s ionosphere. In situ measurements indicated the presence of negatively charged particles with mass-over-charge ratios up to 13,800 u/q. At present, only a handful of anions have bee…
Membership and fundamental parameters of the Praesepe cluster based on Gaia-DR2
Gao, Xin-hua
In this paper, we investigate membership and fundamental astrophysical parameters of the nearby, intermediate-age Praesepe star cluster (M44) based on the Gaia data release 2 (Gaia-DR2). Based on 54 425 stars within a sky area of 5.5° radius, we identify 1111 likely cluster members (≥0.6) in an 11D parameter space based on a combined machine-learn…
Is Supernova Remnant Cassiopeia A a PeVatron?
Zhang, Xiao; Liu, Siming
Cassiopeia A, a well-observed young core-collapse supernova remnant (SNR), is considered to be one of the best candidates for studying very high-energy particle acceleration up to PeV via the diffusive shock mechanism. Recently, MAGIC observations revealed a γ-ray spectral cutoff at ∼ 3.5 {TeV}, suggesting that if the TeV γ-rays have a hadronic or…
Halo intruders in the Galactic bulge revealed by HST and Gaia: the globular clusters Terzan 10 and Djorgovski 1
Bica, E.; Nardiello, D.; Barbuy, B. +2 more
Context. The low-latitude globular clusters Terzan 10 and Djorgovski 1 are projected in the Galactic bulge, in a Galactic region highly affected by extinction. A discrepancy of a factor of ∼2 exists in the literature in regards to the distance determination of these clusters.
Aims: We revisit the colour-magnitude diagrams (CMDs) of these two …
Identifying Spectral Lines to Study Coronal Mass Ejection Evolution in the Lower Corona
Landi, Enrico; Rivera, Yeimy J.; Lepri, Susan T.
As prominences propagate away from the Sun via a coronal mass ejection (CME), they expand, accelerate, and are strongly heated. The heating is substantial enough to continuously ionize the prominence plasma, making it difficult to follow its dynamic evolution with a single extreme ultraviolet (EUV) narrow-band channel or a white light instrument. …