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Investigation and cartographic representation of Hyperion space images photogrammetric processing results
Nadezhdina, I. E.; Sokolov, A. I.; Nyrtsov, M. V. +1 more
In this paper a new body-fixed coordinate system, based on the results of the processing of saturnian satellite Hyperion surface data, obtained by the Cassini spacecraft and proving the chaotic nature of this satellite rotation, was constructed. In this coordinate system, an approximating triaxial ellipsoid is defined, as well as global orthomosai…
HD 21520 b: a warm sub-Neptune transiting a bright G dwarf
Hellier, Coel; Latham, David W.; Littlefield, Colin +49 more
We report the discovery and validation of HD 21520 b, a transiting planet found with Transiting Exoplanet Survey Satellite and orbiting a bright G dwarf (V = 9.2,
CO outflows from young stars in the NGC2023 cluster
Güsten, R.; Mookerjea, B.; Sandell, G.
Context. Young early-type HAeBe stars are still embedded in the molecular clouds in which they formed. They illuminate reflection nebulae, which shape the surrounding molecular cloud and may trigger star formation. They are therefore ideal places to search for ongoing star formation activity.
Aims: NGC 2023 is illuminated by the Herbig Be sta…
Earth's Ionospheric Response to Solar Activity Phenomena in February-March 2023
Sheiner, O. A.; Vybornov, F. I.
As a result of the analysis of data from vertical and oblique sounding of the ionosphere in February-March 2023 using the new ionospheric index, it was found that solar coronal mass ejections (CMEs) of the loop type lead to a long-term decrease in the critical frequencies F-layer of the ionosphere, while other types of CMEs may not lead to signifi…
Coma and tail of Comet 67P/Churyumov-Gerasimenko during the 2021-2022 apparition
Lara, Luisa; Gray, Zuri; Bagnulo, Stefano +1 more
We present results on the global activity of comet 67P/Churyumov-Gerasimenko (67P), the ROSETTA target, during its first perihelion passage after the mission and after an encounter with planet Jupiter. 67P was observed by broad-band filter imaging at 33 epochs during 2021 May 21 to 2022 June 1. The mean radial flux profiles suggest that 'equilibri…
2017 Outburst of H 1743–322: AstroSat and Swift View
Dewangan, G. C.; Chand, Swadesh; Tripathi, Prakash +4 more
We perform a comprehensive timing and broadband spectral analysis using an AstroSat observation of the low-mass black hole X-ray binary H 1743–322 during its 2017 outburst. Additionally, we use two Swift/XRT observations, one of which is simultaneous with AstroSat and the other taken three days earlier, for timing analysis. The hardness–intensity …
Thermal and kinetic coronal rain diagnostics with Mg II h & k lines
Oliver, R.; Kriginsky, M.
Aims: The aim of this work is to assess the temperature and velocity diagnostics of coronal rain clumps, as observed in the lines formed in the upper chromosphere.
Methods: We performed the temperature diagnostics using inversions of data from nine spectroscopic observations obtained with the IRIS spectrograph in the Mg II h & k line…
Investigation of the nature of the wind interaction in HD 93205 based on multi-epoch X-ray observations
De Becker, Michaël; Arora, Bharti
Context. The study of the X-ray emission from massive binaries constitutes a relevant approach to investigate shock physics. The case of short period binaries may turn out to be quite challenging, especially in very asymmetric systems where the primary wind may overwhelm that of the secondary in the wind interaction. Aims. Our objective consists i…
Fifty Years After the Discovery of the First Stellar-Mass Black Hole: A Review of Cyg X-1
Jiang, Jiachen
Around 50 years ago, the famous bet between Stephen Hawking and Kip Thorne on whether Cyg X-1 hosts a stellar-mass black hole became a well-known story in the history of black hole science. Today, Cyg X-1 is widely recognised as hosting a stellar-mass black hole with a mass of approximately 20 solar masses. With the advancement of X-ray telescopes…
Multi-wavelength photometric study of five contact binaries in the field of globular cluster M4
Brosch, Noah; Jagirdar, Rukmini; Devarapalli, Shanti Priya +4 more
Binary stars are believed to be key determinants in understanding globular cluster evolution. In this paper, we present the Multi-band photometric analyses of five variables in the nearest galactic globular cluster M4, from the observations of CASE, M4 Core Project with HST for four variables (V48, V49, V51, and V55) and the data collected from T4…