Search Publications
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…
Four New Eclipsing Binary Systems in the TESS field: CD-34 13220, HD 295082, TYC 6484-426-1 and TYC 6527-2310-1
Ulaş, Burak
We present the first evidence for the binarity of four targets in the TESS field. The temperatures are estimated by SED analysis and the orbital periods are determined. The TESS light curves of the systems are analyzed and the orbital and the absolute parameters are derived. The targets are also compared to well-studied binary systems with the sam…
Long-term V (RI)c CCD photometry of pre-main-sequence stars in the association Cepheus OB3
Ibryamov, Sunay; Semkov, Evgeni; Peneva, Stoyanka +1 more
Results from optical CCD photometric observations of 13 pre-main-sequence stars collected during the period from February 2007 to November 2020 are presented. These stars are located in the association Cepheus OB3, in the field of the young star V733 Cephei. Photometric observations, especially concerning the long-term variability of the stars, ar…