Kazan state Federal University E-Archive :: Browsing by Author "Sakhibullin N."

Multipassband photometric mapping of three fast rotating stars: HII 1883, AP 86 and AP 226

Kolbin A.; Sakhibullin N.; Gabdeev M. (2015)

© 2014 COSPAR. The analysis of multipassband photometry was carried out for three rapidly rotating stars: HII 1883, AP 86 and AP 226. Two different approaches were used for starspot mapping. In the first approach the stellar ...

Neutron-Capture Elements in Halo, Thick-Disk, and Thin-Disk Stars: Neodymium

Mashonkina L.; Kamaeva L.; Samotoev V.; Sakhibullin N. (2004)

We have derived the LTE neodymium abundances in 60 cool stars with metallicities [Fe/H] from 0.25 to -1.71 by applying a synthetic-spectrum analysis to spectroscopic observations of NdII lines with a resolution of λ/Δλ ≃ ...

Non-LTE analyses of strontium abundances in stars: A stars

Belyakova E.; Mashonkina L.; Sakhibullin N. (1999)

The formation of SrII lines in the atmospheres of stars of various types in the absence of local thermodynamic equilibrium (LTE) is analyzed. Departures from LTE are insignificant for normal-metallicity stars with T eff ≤ ...

Non-LTE effects for Na I lines in X-ray illuminated stellar atmospheres

Sakhibullin N.; Shimansky V. (2000)

The formation of Na I lines in X-ray illuminated atmospheres is investigated by abandoning the assumption of local thermodynamic equilibrium (LTE). Calculations are performed on the basis of a 21-level Na I model atom for ...

Non-LTE effects in Mg I lines for various types of stars

Shimanskaya N.; Mashonkina L.; Sakhibullin N. (2000)

We have performed a detailed statistical-equilibrium analysis based on a 49-level model of the magnesium atom for the atmospheres of stars of various spectral types: Teff = 4500-12000 K, logg = 0.0 - 4.5, and [M/H] = 0 to ...

Non-LTE effects in Na I spectral lines in stellar atmospheres

Mashonkina L.; Shimanskiǐ V.; Sakhibullin N. (2000)

The paper examines the statistical equilibrium of Na I in stellar atmospheres with a wide range of parameters: Teff = 4000-12 500 K, log g = 0.0-4.5, and heavy element content [A] from 0.5 to -4.0. The effect of the ...

Observational Constraints on Potassium Synthesis during the Formation of Stars of the Galactic Disk

Shimansky V.; Bikmaev I.; Galeev A.; Shimanskaya N.; Ivanova D.; Sakhibullin N.; Musaev F.; Galazutdinov G. (2003)

The non-LTE potassium abundances in the atmospheres of 33 Galactic-disk stars are derived and the parameters of the atmospheres of 23 of the stars are determined. Neglecting departures from LTE results in a systematic ...

Observational restrictions on sodium and aluminium abundance variations in evolution of the galaxy

Menzhevitski V.; Shimanskaya N.; Shimansky V.; Sakhibullin N. (2013)

In this paper we construct and analyze the uniform non-LTE distributions of the aluminium ([Al/Fe]-[Fe/H]) and sodium ([Na/Fe]-[Fe/H]) abundances in the sample of 160 stars of the disk and halo of our Galaxy with metallicities ...

Observations of the optical afterglow from GRB 060526 with the RTT-150 telescope

Khamitov I.; Burenin R.; Bikmaev I.; Sakhibullin N.; Pavlinsky M.; Sunyaev R.; Aslan Z. (2007)

Multicolor photometric observations of the optical afterglow from GRB 060526 with the Russian-Turkish 1.5-m RTT-150 telescope (Mount Bakyrlytepe, Turkey) are presented. The afterglow light curve was measured in detail ...

On the reconstruction of the surface structure of the spotted stars

Kolbin A.; Shimansky V.; Sakhibullin N. (2013)

We have developed and tested a light-curve inversion technique for photometric mapping of spotted stars. The surface of a spotted star is partitioned into small area elements, over which a search is carried out for the ...

Optical identifications of five INTEGRAL hard X-ray sources in the Galactic plane

Bikmaev I.; Burenin R.; Revnivtsev M.; Sazonov S.; Sunyaev R.; Pavlinsky M.; Sakhibullin N. (2008)

The results of optical identifications of five hard X-ray sources in the Galactic plane from the INTEGRAL all-sky survey are presented. The X-ray data on one source (IGR J20216+4359) are published for the first time. The ...

Optical identifications of INTEGRAL / RXTE sources with 1.5-meter optical telescope RTT150

Bikmaev I.; Revnivtsev M.; Burenin R.; Sunyaev R.; Sakhibullin N. (2006)

We present the first results of our project on optical identifications of INTEGRAL / RXTE hard X-ray sources by using scientific instrumentations of the 1.5-meter joint Russian-Turkish optical telescope RTT150. As the ...

Optical observations of SBS1520+530 at TUG

Khamitov I.; Bikmaev I.; Aslan Z.; Sakhibullin N.; Vlasyuk V.; Zheleznyak A. (2008)

We present the light curves of the components of gravitationally lensed source SBS1520+530 in Rc band, obtained during the interval 2001-2005 with the 1.5 m Russian-Turkish Telescope RTT150 at TÜBITAK National Observatory ...

PG 1316+678: A young pre-cataclysmic binary with weak reflection effects

Shimansky V.; Borisov N.; Bikmaev I.; Sakhibullin N.; Shimanskaya N.; Spiridonova O.; Irtuganov E. (2013)

The PG 1316+678 star is classified as a pre-cataclysmic binary, as is evidenced by its photometric and spectroscopic observations. Its orbital period is determined to be Porb = 3. 3803d, which coincides with the photometric ...

Photometry and spectroscopy of IGR J21247+5058 radiogalaxy with RTT150

Khamitov I.; Bikmaev I.; Sakhibullin N.; Aslan Z.; Revnivtsev M.; Sunyaev R. (2006)

We present the results of photometry and spectroscopy of IGR J21247+5058 made by using the 1.5-m optical telescope RTTl50 with Andor CCD and TFOSC instrument. R-band images obtained at 0.8 arcsec seeing conditions have ...

Preliminary results of the alignment and Hartmann tests of the AZT-22 telescope

Aslan Z.; Bikmaev I.; Vitrichenko E.; Gumerov R.; Dembo L.; Kamus S.; Keskin V.; Kiziloglu U.; Pavlinsky M.; Panteleev L.; Sakhibullin N.; Selam S.; Sunyaev R.; Khamitov I.; Yaskovich A. (2001)

The AZT-22 telescope installed in Turkey (Antalia) was aligned and tested on stars by the Hartmann method. The rms normal deviation of an equivalent optical system is 0.040 ± 0.016 μm. The circle of confusion is 0.40 ± ...

RBS 1032: A dwarf-nucleated spheroidal galaxy with an intermediate-mass black hole hosted in a globular cluster

Ghosh K.; Suleymanov V.; Bikmaev I.; Shimansky S.; Sakhibullin N. (2006)

We report here the multiwavelength observations of the bright supersoft X-ray source, RBS 1032. Most likely, its optical counterpart is a non-emission-line dwarf galaxy with a prominent nucleus. Line and band indices of ...

Spectral types of four binaries based on photometric observations

Shimanskii V.; Bikmaev I.; Borisov N.; Vlasyuk V.; Galeev A.; Sakhibullin N.; Spiridonova O. (2008)

We present results of photometric and spectroscopic observations of four close binaries with subdwarf B components: PG 0918+029, PG 1000+408, PG 1116+301, PG 0001+275. We discovered that PG 1000+408 is a close binary, with ...

Spectroscopic study of the optical counterpart to the fast X-ray transient IGR J17544-2619 based on observations at the 1.5-m RTT-150 telescope

Bikmaev I.; Nikolaeva E.; Shimansky V.; Galeev A.; Zhuchkov R.; Irtuganov E.; Melnikov S.; Sakhibullin N.; Grebenev S.; Sharipova L. (2017)

© 2017, Pleiades Publishing, Inc. We present the results of our long-term photometric and spectroscopic observations at the Russian–Turkish RTT-150 telescope for the optical counterpart to one of the best-known sources, ...

Supersoft X-ray sources. Parameters of stellar atmospheres

Ibragimov A.; Suleǐmanov V.; Vikhlinin A.; Sakhibullin N. (2003)

ROSAT spectra of 11 supersoft X-ray sources are approximated with theoretical spectra obtained in LTE models for the atmospheres of hot white dwarfs with line blanketing. The confidence intervals of parameters derived from ...

Browsing by Author "Sakhibullin N."

Browsing by Author "Sakhibullin N."

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