Search Publications
Revealing the Elusive Companion of the Red Giant Binary 2MASS J05215658+4359220 from UV HST and Astrosat/UVIT Data
Hutchings, John; Thilker, David; Bianchi, Luciana +2 more
Black hole (BH) demographics in different environments is critical in view of recent results on massive star binarity, and of the multimessenger detectability of compact object mergers. But the identification and characterization of noninteracting BHs are elusive, especially in the sparse field stellar population. A candidate noninteractive BH + r…
Spectroscopic Binary Cepheid V350 Sgr: Revision of Physical Characteristics and Evolutionary Status
Rastorguev, A. S.; Gorynya, N. A.; Zabolotskikh, M. V.
Based on the original version of the pulsating photosphere method that allows modeling the changes in the effective temperature, a revision of the physical characteristics of the unique binary Cepheid V350 Sgr was carried out. Previously published measurements of radial velocities were used, as well as new ones obtained by us, which allowed us to …
X-Ray Views of Galactic Accreting Pulsars in High-Mass X-Ray Binaries
Weng, Shan-Shan; Ji, Long
Accreting X-ray pulsars, located in X-ray binaries, are neutron stars with magnetic fields as strong as
Comparing dark matter and MOND hyphotheses from the distribution function of A, F, early-G stars in the solar neighbourhood
Arifyanto, M. I.; Syaifudin, M. A.; Wulandari, H. R. T. +1 more
Dark matter is hypothetical matter assumed to address the historically known as missing mass problem in galaxies. However, alternative theories, such as Modified Newtonian Dynamics (MOND), have been notably successful in explaining the missing mass problem in various astrophysical systems. The vertical distribution function of stars in the solar n…
Formation of a streamer blob via the merger of multiple plasma clumps below 2 R⊙
Fu, Hui; Xia, Lidong; Huang, Zhenghua +7 more
Context. Propagating streamer blobs could be an important source of disturbances in the solar wind. Direct observations of the formation of streamer blobs could be a proxy for understanding the formation of small-scale structures and disturbances in the solar wind.
Aims: We aim to investigate how a streamer blob is formed before it is observe…
High-speed scientific spacecraft launches with commercial launch vehicles
McNutt, Ralph L.; Brandt, Pontus C.; Vernon, Steven R. +2 more
Reaching the outer solar system and interstellar space beyond has always been challenging due to the long distances and long travel times. Initial work on planetary gravity assists in the early 1960s by Minovitch and Flandro laid the basis for expanding reachable space with then-existing launch vehicles. Such gravity assists have been key enablers…
Photometric Analysis for Asteroid (81) Terpsichore using Convex Inversion and Phase Function Fitting Methods
Gao, Quangui; Li, Huaizhen; Qin, Longhua +5 more
The shapes and rotation states (periods and pole orientations) of main-belt asteroids are important for understanding their formation and evolution. In order to obtain sufficient photometric data covering different apparitions for asteroid (81) Terpsichore, ground-based photometric observations in 2020 and 2021 were carried out. By combining publi…
Resolving Red Giant Winds with the Hubble Space Telescope
Harper, Graham M.; Wood, Brian E.; Müller, Hans-Reinhard
We describe recent spectroscopic observations of red giant stars made by the Space Telescope Imaging Spectrograph (STIS) instrument on board the Hubble Space Telescope, which has provided spatially resolved observations of the warm chromospheric winds that predominate for early K to mid-M giants. The H I Lyα lines of a set of 11 red giants observe…
KIC 6362386: An Eclipsing Binary with γ Doradus–type Pulsations and Starspots
Zhang, Xiaobin; Zong, Weikai; Wang, Jiaxin +5 more
KIC 6362386 is an eclipsing binary system that exhibits both γ Doradus (γ Dor)–type pulsations and starspots. In this study, we investigated this binary system using the Kepler photometry and the spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. After employing the PHOEBE program for light-curve and radial-velo…
Primeros resultados del estudio observacional de estrellas masivas y centrales en cúmulos abiertos
González, J. F.; Alejo, A. D.; González, S. P.
Theoretical models show that binary and multiple stars play an important rol in the energetics of open clusters and therefore in their dynamical evolution, particulary in poor clusters dominated by one or a few central massive stars. In this work we present the results of our spectroscopic, astrometric and photometric analysis of four young open c…