Search Publications
Two-stream plasma instability as a potential mechanism for particle escape from the Venusian ionosphere
Ghosh, S.; Chandra, S.; Dey, S. +2 more
In this work we investigate the possibility of two-stream instability in the Venusian atmosphere to lead to momentum transfer to subsequent escape of Hydrogen and Oxygen ions from the ionosphere. We employ the hydrodynamic model and obtain the linear dispersion relation from which the two-stream instability is studied. Further the interaction of s…
Recent star formation history of the dwarf irregular galaxy Leo A
Stonkutė, Rima; Vansevičius, Vladas; Leščinskaitė, Alina
Context.
KMHK 1762: Another star cluster in the Large Magellanic Cloud age gap
Cignoni, M.; Tosi, M.; Ripepi, V. +11 more
Context. The star cluster (SC) age distribution of the Large Magellanic Cloud (LMC) exhibits a gap from ∼4 to 10 Gyr ago, with an almost total absence of SCs. Within this age gap, only two confirmed SCs have been identified hitherto. Nonetheless, the star field counterpart does not show the same characteristics, making the LMC a peculiar galaxy wh…
Analysis of eight magnetic chemically peculiar stars with rotational modulation
Paunzen, E.; Bowman, D. M.; Shultz, M. E. +9 more
Since the end of 2018, the Transiting Exoplanet Survey Satellite (TESS) has provided stellar photometry to the astronomical community. We have used TESS data to study rotational modulation in the light curves of a sample of chemically peculiar stars with measured large-scale magnetic fields (mCP stars). In general, mCP stars show inhomogeneous dis…
Distances to Local Group Galaxies via Population II, Stellar Distance Indicators. II. The Fornax Dwarf Spheroidal
Madore, Barry F.; Freedman, Wendy L.; Cerny, William +5 more
We determine three independent Population II distance moduli to the Fornax dwarf spheroidal (dSph) galaxy, using wide-field, ground-based VI imaging acquired with the Magellan-Baade telescope at Las Campanas Observatory. After subtracting foreground stars using Gaia EDR3 proper motions, we measure an I-band tip of the red giant branch (TRGB) magni…
Video observations of tiny near-Earth objects with Tomo-e Gozen
Kobayashi, Naoto; Takita, Satoshi; Usui, Fumihiko +20 more
We report the results of video observations of tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on the Kiso 105 cm Schmidt telescope. The rotational period of a tiny asteroid reflects its dynamical history and physical properties since smaller objects are sensitive to the Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effe…
Exploring the Origin of Stealth Coronal Mass Ejections with Magnetofrictional Simulations
Yeates, A. R.; Bhowmik, P.; Rice, O. E. K.
Coronal mass ejections (CMEs) - among the most energetic events originating from the Sun - can cause significant and sudden disruption to the magnetic and particulate environment of the heliosphere. Thus, in the current era of space-based technologies, early warning that a CME has left the Sun is crucial. Some CMEs exhibit signatures at the solar …
Orbital and atmospheric parameters of two wide O-type subdwarf binaries: BD−11o162 and Feige 80
Németh, Péter; Tkachenko, Andrew; van Winckel, Hans +4 more
Context. There are 23 long-period binary systems discovered to date that contain a B-type hot subdwarf whose orbital parameters have been fully solved. They evolve into O-type subdwarfs (sdO) once the helium burning transitions from the core to the He shell. Their study will help constraint parameters on the formation and evolution of these binari…
An intermediate polar candidate toward the Galactic plane
Campana, S.; Haberl, F.; Ponti, G. +5 more
Context. For the past decade, it has been suggested that intermediate polars (IPs), a subclass of magnetic cataclysmic variables (CVs), are one of the main contributors to the hard diffuse X-ray emission from the Galactic center (GC) and Galactic ridge.
Aims: In our ongoing XMM-Newton survey of the central region of the Galactic disk (20° ×2°…
Convective storms in closed cyclones in Jupiter: (II) numerical modeling
Hueso, Ricardo; Sánchez-Lavega, Agustín; Legarreta, Jon +1 more
On May 31, 2020 a convective storm appeared in one small cyclone in the South Temperate Belt (STB) of Jupiter. The storm, nicknamed as Clyde's Spot, had an explosive start and quickly diminished in activity in a few days. However, it left a highly turbulent cyclone as a remnant that evolved to become a turbulent segment of the STB in a time-scale …