Search Publications
Microquasar V404 Cyg /GS 2023+338: MASTER optical observations during the June and December 2015 super-outbursts
Rebolo, R.; Wang, X.; Buckley, D. A. H. +22 more
We present several thousands homogeneous photometric (WBVRI and polarization) observations of the microquasar black hole binary V404 Cyg, obtained by the MASTER Global Robotic Network (Lipunov et al. 2010). MASTER were the first telescopes to optically monitor the microquasar after its gamma-ray onset from 18 h 34 m 09 s UT on June 15, 2015 (), un…
Photometry study in period variation and orbital parameter of two W UMa eclipsing binaries: AV Crb and EK Aqr
Han, Xianming L.; Lu, Hong-peng; Zhang, Li-yun +2 more
We report new light curves of two eclipsing binaries of AV Crb and EK Aqr obtained in 2017 and 2018 using Holcomb and SARA telescopes. We obtain the updated ephemeris and find a continuous period decrease (AV Crb) and increase (EK Aqr), respectively. We used the 2015 version Wilson-Devinney method to analyze the light curves and asymmetries. The e…
PY Boo and NSVS 7328383: Two totally-eclipsing W UMa stars with small mass ratios and close parameters
Popov, Velimir A.; Petrov, Nikola I.; Kjurkchieva, Diana P.
Photometric observations of the W UMa binaries PY Boo and NSVS 7328383 with periods of around 0.27 d are presented. The light curve solutions reveal that the components of both targets are stars of K type (temperatures T1=4770 K, T2=5080 K and T1=5146 K, T2=5056 K, respectively,) and undergo total eclips…
OT UMa and GU leo: Two middle-contact w UMa binaries with similar stellar components
Michel, Raul; Kjurkchieva, Diana; Guerrero, Carlos
We present photometric observations of the W UMa binaries OT UMa and UG Leo. Our results from the light curve solutions are: (i) The two targets show partial eclipses; (ii) The components OT UMa and UG Leo are of G spectral type; (iii) Detailed q-search analysis was carried out for determination of the mass ratios; (iv) The two binaries are of W s…
TYC 3637-1152-1 - A high amplitude δ Scuti star with peculiar pulsational properties
Meingast, Stefan; Sulzenauer, Nikolaus; Pribulla, Theodor +16 more
In some δ Scuti stars, only one or two radial modes are excited (usually the fundamental mode and/or first overtone mode) and the observed peak-to-peak amplitudes exceed 0.3 mag (V). These stars are known as High Amplitude Delta Scuti (HADS) variables.
We here present a detailed photometric and spectroscopic analysis of the HADS star TYC 3637…Characterization of eclipsing binaries in High Latitude Field 356
Smits, Derck P.; Skelton, P. L.
Variable stars in HLF 356 identified from plates taken at Harvard Observatory southern station in the 1930s are characterised using data from the ASAS, SuperWASP and Catalina Sky Survey databases. Very little work has been done on these variables since their discovery. Their periods are determined, and light curves for these stars are presented, f…
A search for peculiar stars in the open cluster Hogg 16
Paunzen, Ernst; Netopil, Martin; Cariddi, Stefano +5 more
The study of chemically peculiar (CP) stars in open clusters provides valuable information about their evolutionary status. Their detection can be performed using the Δa photometric system, which maps a characteristic flux depression at λ ∼ 5200 Å. This paper aims at studying the occurrence of CP stars in the earliest stages of evolution of a stel…
Star formation history: Modeling of visual binaries
Tutukov, A. V.; Kovaleva, D. A.; Malkov, O. Yu. +3 more
Most stars form in binary or multiple systems. Their evolution is defined by masses of components, orbital separation and eccentricity. In order to understand star formation and evolutionary processes, it is vital to find distributions of physical parameters of binaries.
We have carried out Monte Carlo simulations in which we simulate differe…V1719 Aql: A solar-type twin binary
Bakış, Volkan; Yücel, Gökhan; Bakış, Hicran
Stellar parameters of the solar type twin binary V1719 Aql have been derived with relatively high accuracy. The erroneous known orbital period was corrected. The true period of the system (P = 4.35 days) is twice the value known in the literature. The system is located at 77 ± 3 pc from the Sun, which matches, within the uncertainty box, the dista…
Star formation toward the H II region IRAS 10427-6032
Chen, Wen-Ping; Samal, Manash R.; Vaidya, Kaushar +3 more
The formation and properties of star clusters formed at the edges of the H II regions are poorly known. In this paper, we study stellar content, physical conditions, and star formation processes around a relatively unknown young H II region IRAS 10427-6032, located in the southern outskirts of the Carina Nebula. We study this region by making use …