Search Publications
X-Ray and Spectral Ultraviolet Observations of Periodic Pulsations in a Solar Flare Fan/Looptop
Reeves, Katharine K.; Kazachenko, Maria D.; Lörinčík, Juraj +3 more
We present simultaneous X-ray and spectral ultraviolet observations of strikingly coherent oscillations in emission from a coronal looptop and fan structure, during the impulsive phase of a long-duration M-class solar flare. The ≈50 s oscillations are observed near in-phase by Solar Orbiter/STIX, GOES, and IRIS Fe XXI intensity, Doppler, and nonth…
IRIS Observational Approach to the Oscillatory and Damping Nature of Network and Internetwork Chromosphere Small-Scale Brightening (SSBs) and Their Unusual Dynamical and Morphological Differences in Different Regions on the Solar Disk
Tavabi, Ehsan; Sadeghi, Rayhaneh
One of the most exciting benefits of solar small-scale brightening is their oscillations. This study investigated the properties of small-scale brightening (SSBs) in different regions of the Sun and found that there are differences and similarities in the properties of oscillated and non-oscillated SSBs in different regions of the Sun, including q…
KPF Confirms a Polar Orbit for KELT-18 b
Howard, Andrew W.; Petigura, Erik A.; Behmard, Aida +24 more
We present the first spectroscopic transit results from the newly commissioned Keck Planet Finder on the Keck-I telescope at W. M. Keck Observatory. We observed a transit of KELT-18 b, an inflated ultrahot Jupiter orbiting a hot star (T eff = 6670 K) with a binary stellar companion. By modeling the perturbation to the measured cross-cor…
Solar Soft X-ray Irradiance Variability III: Magnetic Field Variations of Coronal X-ray Features
Matsumoto, Takuma; Masuda, Satoshi; DeLuca, Edward +7 more
The magnetic field changes the radiative output of the Sun and is the main source for all the solar surface features. To study the role of the underlying photospheric magnetic field in relation to emission features observed in the solar corona, we have used the full-disk soft X-ray images from Hinode/X-Ray Telescope (Hinode/XRT) and the magnetogra…
Magnetic Helicity Signs and Flaring Propensity: Comparing the Force-free Parameter with the Helicity Signs of Hα Filaments and X-Ray Sigmoids
Martens, Petrus C.; Georgoulis, Manolis K.; Aparna, V.
Sigmoids produce strong eruptive events. Earlier studies have shown that the ICME axial magnetic field Bz can be predicted with some credibility by observing the corresponding filament or the polarity inversion line in the region of eruption and deriving the magnetic field direction from that. Sigmoids are coronal structures often associated with …
Correcting Fabry-Pérot etalon effects in solar observations
Blanco Rodríguez, J.; Orozco Suárez, D.; Bailén, F. J. +1 more
Context. Data processing pipelines of Fabry-Pérot interferometers (FPI) must take into account the side effects these devices introduce in the observations. Interpretation of these observations without proper correction can lead to inaccurate or false results, with consequent impact on their physical interpretation. Corrections typically require p…
Skewness and kurtosis of solar wind proton distribution functions: The normal inverse-Gaussian model and its implications
André, N.; Fedorov, A.; Livi, S. +27 more
Context. In the solar wind (SW), the particle distribution functions are generally not Gaussian. They present nonthermal features that are related to underlying acceleration and heating processes. These processes are critical in the overall dynamics of this expanding astrophysical fluid.
Aims: The Proton Alpha Sensor (PAS) on board Solar Orbi…
HR 10 as seen by CHEOPS and TESS: Revealing δ Scuti pulsations, granulation-like signal and hint for transients
Alonso, R.; Deleuil, M.; Erikson, A. +78 more
Context. HR 10 has only recently been identified as a binary system. Previously thought to be an A-type shell star, it appears that both components are fast-rotating A-type stars, each presenting a circumstellar envelope. Although showing complex photometric variability, spectroscopic observations of the metallic absorption lines reveal variation …
Unveiling very young O stars. Two Galactic O2V((f*))z in Westerlund 2
Roman-Lopes, A.
Context. O-type stars are known to significantly contribute to both the dynamics and evolution of galaxies. Massive and luminous, they probably control and regulate the galaxies star formation rates. The stellar feedback generated by such cosmic beasts can strongly affect the local star formation rate, with effects in the current (and future) gene…
Planetary orbital mapping and mosaicking (POMM) integrated open source software environment
Logan, Thomas L.; Smyth, Michael M.; Calef, Fred J.
Several Open Source planetary orbital mapping and utility image processing software packages, including, VICAR, AFIDS, ISIS, GDAL, and GeoTIFF, have been integrated into a single software environment (POMM), where package programs can be run independently from a Linux command line, or combined in synergistic scripts that facilitate advanced trans-…