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Spectroflat: A generic spectrum and flat-field calibration library for spectro-polarimetric data
Feller, A.; Iglesias, F. A.; Doerr, H. -P. +1 more
Context. Flat-fielding spectro-polarimetric data with one spatial and one spectral dimension is inherently difficult as the imprint of the spectral lines needs to be separated from other wavelength-dependent instrumental effect (e.g., fringes or prefilter profiles) and wavelength-independent effects (e.g., dust and sensor response). Current approa…
Analysis of Overtones in Transverse Oscillations of Coronal Loops of an Active Region
K., Safna Banu; Maurya, Ram Ajor
We investigate the fundamental mode and overtones in the transverse oscillations of coronal loops associated with an active region using intensity observations taken by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO). The fundamental periods of the two selected coronal loops are found to be 17.0 minutes and 15.2…
Role of nonlinear structures and associated turbulence generation dayside magnetosphere reconnection sites
Sharma, R. P.; Pathak, Neha; Sharma, Suresh C. +1 more
A numerical simulation is implemented to investigate the role of whistler wave in the presence of the ponderomotive force-driven density modification and the magnetic field perturbation due to preexisting magnetic islands. The dynamical equation governing the whistler waves is derived and solved using numerical methods to assess their role. The si…
Modelling non-radially propagating coronal mass ejections and forecasting the time of their arrival at Earth
Magdalenic, J.; Valentino, A.
We present the study of two solar eruptive events observed on December 7 2020 and October 28 2021. Both events were associated with full halo coronal mass ejections (CMEs) and flares. These events were chosen because they show a strong non-radial direction of propagation in the low corona and their main propagation direction observed in the inner …
Mass, Density, and Radius of Asteroid (16) Psyche from High-precision Astrometry
Chesley, Steven R.; Farnocchia, Davide; Park, Ryan S. +2 more
We characterize asteroid (16) Psyche using high-precision astrometry, including the recent Gaia Focused Product Release. The gravitational perturbations of Psyche on other asteroids can be observable in the case of mutual encounters. Using a least squares approach, we estimate the mass of Psyche by fitting astrometric data of asteroids that come w…
Large-scale Plasma Vortex in the Magnetotail of Venus
Chai, Lihui; Guo, Mengdan; Tang, Xiaozhun
Using the observations by the Analyzer of Space Plasmas and Energetic Atoms on Venus (ASPERA-4) onboard Venus Express, Previous studies found A large-scale plasma vortices of solar wind hydrogen ions (H+) and Venus ionospheric oxygen ions (O+) in the magnetotail of Venus. The vortex is counterclockwise when viewed from the ta…
Propagation of Galactic Cosmic Rays in the Heliosphere during Minimum Solar Activity Periods
Fedorov, Yu. I.
Based on the cosmic ray transport equation, the propagation of charged high-energy particles in heliospheric magnetic fields is considered. The transport equation solution is found in the approximation of low anisotropy in the angular distribution of particles. The energy distribution of galactic cosmic rays at a heliopause is used as a boundary c…
Pulse frequency variations and timing noise of MXB 0656–072 during the 2007–2008 type I outbursts and implications for its magnetic field
Santangelo, A.; Serim, M. M.; Baykal, A. +4 more
Aims. We aim to explore the properties of the Be/X-ray binary system MXB 0656–072 from a timing analysis perspective through an investigation of the RXTE/PCA and Fermi/GBM data during its 2007–2008 type I outbursts. Methods. We applied two new techniques, for the first time, along with the conventional Deeter method to produce higher-resolution po…
Characterization of Magnetic Flux Contents for Two Flux Transfer Events From Both In Situ and Ionospheric Observations
Hasegawa, Hiroshi; Wang, Shuo; Hu, Qiang +2 more
Flux transfer events (FTEs) are a type of magnetospheric phenomena that exhibit distinctive observational signatures from the in situ spacecraft measurements. They are generally believed to possess a magnetic field configuration of a magnetic flux rope and formed through magnetic reconnection at the dayside magnetopause, sometimes accompanied with…
Discovery of double stars by Giovanni Battista Hodierna in 1654
Caballero, J. A.; González-Payo, J.
It has been generally accepted that the originators of the double star astronomy were Christian Mayer and William Herschel. We recovered the memory of the poorly known Italian astronomer Giovanni Battista Hodierna, who published the first catalogue of stellar binaries over a century before Mayer and Herschel. We analysed the fourth section of 1654…