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The evolution of coronal shock wave properties and their relation with solar energetic particles
Kouloumvakos, Athanasios; Rouillard, Alexis P.; Dresing, Nina +5 more
Context. Shock waves driven by fast and wide coronal mass ejections (CMEs) are considered to be very efficient particle accelerators and are involved in the production of solar energetic particle (SEP) events. These events cause space weather phenomena by disturbing the near-Earth radiation environment. In past studies, we analysed statistically t…
Two Long-period Giant Planets around Two Giant Stars: HD 112570 and HD 154391
Zhao, Gang; Wang, Wei; Song, Nan +24 more
We present the discoveries of two giant plants orbiting the red-giant-branch star HD 112570 and the red-clump star HD 154391, based on the radial-velocity (RV) measurements from the Xinglong station and Okayama Astrophysical Observatory. Spectroscopic and asteroseismic analyses suggest that HD 112570 has a mass of 1.15 ± 0.12 M ☉, a rad…
Multiwavelength radiation from the interaction between magnetar bursts and a companion star in a binary system
Wei, Da-Ming; Wei, Yu-Jia; Yang, Yuan-Pei +1 more
Magnetars are young, highly magnetized neutron stars that are associated with magnetar short bursts (MSBs), magnetar giant flares (MGFs), and at least some fast radio bursts (FRBs). In this work, we consider a magnetar and a main sequence star in a binary system and analyze the properties of the electromagnetic signals generated by the interaction…
A case study of oversight and neglect in the handling of massive data
Pera, M. S.; Vázquez, R. A.; Giorgi, E. E. +2 more
We present and discuss data coming from the Gaia Data Release 3 mission up to $G = 21$ mag in two stellar fields covering about 5 square degrees in the area of the open cluster NGC 2659 in the region of Vela. In combination with the pyUPMASK and ASteCA analysis packages, Gaia data provide membership probabilities, structure and fundamental paramet…
Near-UV and Optical Spectroscopic Investigation of Late-type Stars from the MIRA/Oliver Observing Station
Karmakar, Subhajeet; Pandey, Jeewan Chandra; Shedge, Riddhi +4 more
Late-type stars are the most abundant in the galactic stellar population. These stars, with the similar internal structure to the Sun, are expected to have solar-like atmospheres. Investigating the stellar parameters and chemical abundances on late-type stars is essential to provide valuable constraints about stellar age, chemical evolution, and a…
Phase-dependent Spectral Shape Changes in the Ultraluminous X-Ray Pulsar NGC 5907 ULX1
Yamaguchi, Hiroya; Kobayashi, Shogo B.; Miura, Daiki
The discovery of coherent pulsations from several ultraluminous X-ray pulsars (ULXPs) has provided direct evidence of a supercritical accretion flow. However, the geometrical structure of such an accretion flow onto the central neutron star remains poorly understood. NGC 5907 ULX1 is one of the most luminous ULXPs, with a luminosity exceeding 10
Absolute Dimensions of the Interferometric Binary HD 174881: A Test of Stellar Evolution Models for Evolved Stars
Torres, Guillermo; Monnier, John D.; van Belle, Gerard T. +1 more
We report high-resolution spectroscopic monitoring and long-baseline interferometric observations with the Palomar Testbed Interferometer (PTI) of the 215 day binary system HD 174881 (K1 II-III), composed of two giant stars. The system is spatially resolved with the PTI, as well as in archival measurements with the CHARA Array. Our analysis of the…
Dual Sources of S2 Observed in Comet 67P: Insights from Comparing ROSINA Measurements and Laboratory Simulations
Choukroun, Mathieu; Hodyss, Robert; Mahjoub, Ahmed +2 more
Hydrogen sulfide (H2S) is the fifth most abundant molecule observed in the coma of comet 67P/Churyumov–Gerasimenko (67P). Prior to its incorporation into cometary materials, H2S likely underwent ultraviolet (UV) radiation exposure, which is thought to initiate a complex sulfur chemistry. We present an investigation into the U…
ATOMS: ALMA three-millimetre observations of massive star-forming regions-XVII. High-mass star-formation through a large-scale collapse in IRAS 15394-5358
Sanhueza, Patricio; Tej, Anandmayee; Hwang, Jihye +23 more
Hub-filament systems are considered as natural sites for high-mass star formation. Kinematic analysis of the surroundings of hub-filaments is essential to better understand high-mass star formation within such systems. In this work, we present a detailed study of the massive Galactic protocluster IRAS 15394
ObsMap: Preparing observing maps with the best comparison stars for photometry
Esmer, E. M.; Baştürk, Ö.; Yalçınkaya, S.
We present ObsMap, a Python framework that allows for the interactive creation of various alternative observation maps to maximize the potential of each observing night. The code requires the user to input the star's name or equatorial coordinates, the passband of observation, field of view (FoV), and desired count level together with the minimum …