Search Publications
The Improved Orbit Solution and Component Masses of bet LMi
Wang, Xiaoli; Fu, Yanning; Xia, Fang
bet LMi is a double-lined visual binary with an orbital period of ∼39 yr. Via a simultaneous fitting to both astrometric and radial velocity measurements, we give a complete and improved orbit solution with high precision. Then, the component masses are precisely determined as 2.98 ± 0.10 M⊙ and 1.92 ± 0.04 M⊙ with a relative…
Variations in the Plasma Parameters of the Earth's Magnetotail during Substorm Initiation
Grigorenko, E. E.; Kronberg, E. A.; Kozak, L. V. +3 more
A chain of events accompanying the occurrence of a substorm in the Earth's ionosphere and magnetosphere is considered. Features of geomagnetic pulsations and mechanisms of their generation are indicated. Measurements of magnetic field fluctuations from fluxgate magnetometers, as well as the data on temperature, velocity, and concentration of elect…
Discovery of Five New Variables
Liakos, A.
Concerning the Li-rich status of KIC 9821622: a Kepler field RGB star reported as a Li-rich giant
Aoki, Wako; Reddy, Bacham E.; Singh, Raghubar +1 more
Given the implications for the origin of Li enhancement in red giants, we have reviewed the Li-rich classification of KIC 9821622, the only bonafide red giant branch (RGB) giant with a He inert core to date, reported as a Li-rich giant by reanalysing the high-resolution spectra. We have obtained A(Li)LTE = 1.42 ± 0.05 dex. After correct…
Diagnostics of plasma ionisation using torsional Alfvén waves
Ballai, I.
Aims: Using the recently observed torsional Alfvén waves in solar prominences, we determine the ionisation state of the plasma by taking into account that Alfvén waves propagate in a partially ionised prominence plasma. We derive the evolutionary equation of waves and compare the analytical solutions to observations to determine the number de…
Science merit function for the Kepler mission
Jenkins, Jon M.; Borucki, William J.; Duren, Riley M.
The Kepler mission was a National Aeronautics and Space Agency (NASA) Discovery-class mission designed to continuously monitor the brightness of at least 100,000 stars to determine the frequency of Earth-size and larger planets orbiting other stars. Once the Kepler proposal was chosen for a flight opportunity, it was necessary to optimize the desi…
Extended view on the dust shells around two carbon stars
Groenewegen, M. A. T.; Kerschbaum, F.; Aringer, B. +4 more
Context. Stars on the asymptotic giant branch lose considerable amounts of matter through their dust-driven stellar winds. A number of such sources have been imaged by Herschel/PACS, revealing a diverse sample of different morphological types. Among them are a few examples which show geometrically thin, spherically symmetric shells which can be us…
Infrared interferometric imaging of the compact dust disk around the AGB star HR3126 with the bipolar Toby Jug Nebula
Weigelt, G.; Hofmann, K. -H.; Schertl, D. +1 more
Aims: The asymptotic giant branch (AGB) star HR3126, associated with the arcminute-scale bipolar Toby Jug Nebula, provides a rare opportunity to study the emergence of bipolar structures at the end of the AGB phase. Our goal is to image the central region of HR3126 with high spatial resolution.
Methods: We carried out long-baseline inter…
A New Moving Group in the Local Arm
Zhao, Gang; Chen, Yuqin; Zhao, Jingkun +5 more
We present a new moving group clustered in kinematics, spatial position, and elemental abundances. Its spatial position is around the center of the Local Arm of the Milky Way. A convergent point method was taken to select candidate member stars. Among 206 candidate member stars, 74 are pre-main-sequence stars and some of them have stellar disks. W…
Relative Motion in the Hierarchical Triple System ADS48 on the Basis of Gaia DR2 and 26-Inch Refractor of Pulkovo Observatory Data
Zhuchkov, R. Ya.; Kiyaeva, O. V.; Izmailov, I. S.
—According to the exact positions and proper motions of the three components of the star ADS48 from Gaia DR2, their parallax and radial velocities for the epoch 2015.5 the instantaneous relative positions and motions of the components were determined. Only from the Gaia DR2 observations, the family of orbits of the AB pair was calculated by the me…