Search Publications
An investigation of planetary nebulae accompanying PG 1159 central stars, based on Gaia DR2 measurements
Ali, Alaa; Alharbi, Wedad R.
This article discusses the physical and kinematical characteristics of planetary nebulae accompanying PG 1159 central stars. The study is based on the parallax and proper motion measurements recently offered by the Gaia space mission. Two approaches were used to investigate the kinematical properties of the sample. The results revealed that most o…
BGLS-based method of estimating the rotational periods of asteroids
Ren, Yan-Qiong; Lu, Xiao-Ping; Liang, Yong
As the asteroid rotational period is important to the study of the properties of asteroids (e.g., super-fast rotators have structures owing an internal cohesion (rather than being rubble piles bounded by gravity only) so as not to fly apart), constructing an effective and fast method used to search the period attracts much researchers' attention. …
On the photoevaporation, dust polarization and kinematics of two nebulae in Sh2-236
Soam, Archana
In the work presented here, the impact of magnetic field on the dynamical evolution of cometary globules Sim 129 and Sim 130 in the Sh2-236 HII region and the ionized gas streaming out of their surfaces is investigated. The magnetic field morphology in the region associated with these globules is inferred using optical polarization measurements wi…
Estimation of ages and masses via carbon and nitrogen abundances for 556 007 giants from LAMOST
Zhao, Gang; Buder, Sven; Wu, Ya-Qian +1 more
Estimating ages for a large number of giants is of great importance for studying Galactic evolution. In this work, we determine stellar ages and masses for 556 007 giants from LAMOST Data Release 5 (DR5) with empirical relations estimated from chemical [C/N] abundance ratios. Our sample reveals the two well-known sequences in the age-[α/M] relatio…
Revisiting the X-ray emission of the asynchronous polar V1432 Aql
Qian, Sheng-Bang; Zhu, Li-Ying; Wang, Qi-Shan
As the only eclipsing asynchronous polar, V1432 Aql provides an excellent laboratory to study the interaction between the accreted matter and the magnetic field. Here, we report an analysis of the X-ray data from the contemporaneous NuSTAR and Swift-XRT observations. The X-ray data present a profile with a low-intensity state for almost half an or…
Research on the HIP 18856 binary system
Mitrofanova, Arina; Dyachenko, Vladimir; Beskakotov, Anatoly +5 more
The results of a study on the binary HIP 18856 and construction of its orbit are presented. New observational data were obtained at the BTA of SAO RAS in 2007-2019. Earlier, Cvetković et al. constructed the orbit for this system. However, it is based on six measurements, which cover a small part of the orbit. The positional parameters of the ESA a…
Spectral energy distribution similarity of the local galaxies and the 3.6 µm selected galaxies from the Spitzer Extended Deep Survey
Cheng, Cheng; Li, Zi-Jian; Huang, Jia-Sheng +11 more
The Spitzer Extended Deep Survey (SEDS) as a deep and wide mid-infrared (MIR) survey project provides a sample of 500 000+ sources spreading 1.46 square degree and a depth of 26 AB mag (3σ). Combining with the previous available data, we build a PSF-matched multi-wavelength photometry catalog from u band to 8 µm. We fit the SEDS galaxies spe…
Reducing loss of significance in the computation of Earth-based two-way Doppler observables for small body missions
Li, Fei; Ye, Mao; Barriot, Jean-Pierre +5 more
Two-way Doppler measurement is a typical Earth-based radiometric technique for interplanetary spacecraft navigation and gravity science investigation. The most widely used model for the computation of two-way Doppler observables is Moyer's differenced-range Doppler (DRD) formula, which is based on a Schwarzschild approximation of the Solar-System …
Absolute parameters of young stars: PU Pup
Erdem, Ahmet; Sürgit, Derya; Budding, Edwin +2 more
We present combined photometric and spectroscopic analyses of the southern binary star PU Pup. High-resolution spectra of this system were taken at the University of Canterbury Mt. John Observatory in the years 2008 and again in 2014-2015. We find the light contribution of the secondary component to be only ~2% of the total light of the system in …
New observations and transit solutions of the inflated exoplanets HAT-P-40b and HAT-P-51b
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P.
We present high-precision photometric observations of the transiting exoplanets HAT-P-40b and HAT-P-51b by the Rozhen 2-m telescope. The newly-observed transit of HAT-P-40b is the first one with a complete curve. The orbital periods of the two targets were improved. We modeled the observed transits and found bigger stellar radii than those derived…