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1.
Izmailov I. S. Shakht N. A. Polyakov E. V. Gorshanov D. L. Pogodin M. A. 《Astrophysics》2021,64(2):160-171
Astrophysics - This paper is a continuation of our earlier work devoted to determining the orbit and mass of the star 61 Cyg and the changes in the photometric characteristics of its components.... 相似文献
2.
Stars in the Pulkovo Observatory program are observed with a 65-cm refractor during many years to study their positions and movements. We present examples of two visual binary stars, for which orbits and masses of components were determined, and two astrometric stars, for which masses of their unseen companions were estimated. The first two stars are ADS 14636(61 Cygni) and ADS 7251,and the others are Gliese 623 and ADS 8035(Alpha UMa). Direct astrometric methods are used for estimation of mass-ratio and masses. 相似文献
3.
N. A. Shakht L. G. Romanenko D. L. Gorshanov O. O. Vasilkova 《Solar System Research》2016,50(1):56-66
A list of selected binary stars is presented that have been observed for several decades using a 26-inch refractor at the Pulkovo Observatory. These stars are at a distance from 3.5 to 25 pc from the Sun. They belong to spectral classes F, G, K, and M. Their masses range from 0.3 to 1.5 solar masses. We have analyzed them as possible parent stars for exoplanets taking into account the physical characteristics of these stars. In view of dynamic parameters and orbital elements that we have obtained by Pulkovo observations, ephemerides of positions for the coming years are calculated. The boundaries of the habitable zones around these stars are calculated. The astrometric signal that depends on the gravitational influence of hypothetical planets is estimated. Space telescopes for astrometric observations with microsecond accuracy can be used to detect Earth-like planets near the closest stars of this program. This paper presents an overview of astrometric programs of searches for exoplanets. 相似文献
4.
E. N. Sokov I. A. Vereshchagina Yu. N. Gnedin A. V. Devyatkin D. L. Gorshanov V. Yu. Slesarenko A. V. Ivanov K. N. Naumov S. V. Zinov’ev A. S. Bekhteva E. S. Romas S. V. Karashevich V. V. Kupriyanov 《Astronomy Letters》2012,38(3):180-190
Exoplanet observations have been performed on the automated Pulkovo Observatory telescopes. We have obtained 33 transit light curves for 16 known exoplanets and six transit observations for three exoplanet candidates discovered by the Kepler telescope. Based on our observations, we have reliably confirmed the existence of an exoplanet with an extremely large radius, R pl = 1.83 ± 0.16R Jup, in the system KOI 256 and detected a strong deviation of its orbital revolution from the theoretically predicted one. During the transit of the exoplanet WASP-12b across the stellar disk, we detected bursts that could be caused by the planet transit across spots on the star or by the presence of a satellite around this exoplanet. We detected possible periodic variations in the duration of the exoplanet transit across the stellar disk with time for HAT-P-12b that could be caused by variations in orbital inclination. The transit duration and depth, the central transit time, and the radius and orbital inclination of the planet have been estimated. The equilibrium temperature and albedo have been estimated for several exoplanets. 相似文献
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6.
V. N. Frolov Yu. K. Ananjevskaja D. L. Gorshanov E. V. Polyakov 《Astronomy Letters》2010,36(5):338-348
We present the results of our comprehensive study of the Galactic open star cluster NGC 6866. The positions of stars in the
investigated region have been obtained with the “Fantasy” automatic measuring machine from 10 plates of the normal astrograph
at the Pulkovo Astronomical Observatory. The size of the investigated field is 40′ × 40′, the limiting magnitude is B ∼ 16·
m
6, and the maximum epoch difference is 79 yr. For 1202 field stars, we have determined the relative proper motions with an
rms error of 2.5 mas yr−1. Out of them, 423 stars may be considered cluster members with a probability P > 70% according to the astrometric criterion. Photometric diagrams have been used as an additional criterion. We have performed
two-color BV CCD photometry of stars with the Pulkovo ZA-320M mirror astrograph. The U magnitudes from the literature have also been used to construct the two-color diagrams. A total of 267 stars have turned
out to be members of NGC 6866 according to the two criteria. We present refined physical parameters of the cluster and its
age estimate (5.6 × 108 yr). The cluster membership of red and blue giants, variable, double, and multiple stars is considered. We have found an
almost complete coincidence of the positions of one of the stars in the region (a cluster nonmember) and a soft X-ray source
in the ROSAT catalog. The “Fantasy” automatic measuring machine is described in the Appendix. 相似文献
7.
A. A. Kiselev O. V. Kiyaeva I. S. Izmailov L. G. Romanenko O. A. Kalinichenko O. O. Vasil’kova T. A. Vasil’eva N. A. Shakht D. L. Gorshanov E. A. Roschina 《Astronomy Reports》2014,58(2):78-97
The results of long-term, uniform, photographic observations of visual double and multiple stars obtained on the Pulkovo 26″ refractor are presented. Relative positions are calculated for 259 pairs of visual double stars in 194 systems, with the relative motions also computed for 127 pairs. Lower limits for the total masses of the systems for which elliptical orbits possible are also found for 48 pairs with reliable parallaxes from the Hipparcos catalog. The accuracies of the three measuring machines used in the reduction of the photographic plates are compared. Component separations measured with different machines can differ by as much as 0.2″, demonstrating the advantages of using uniform observations. 相似文献
8.
A. V. Devyatkin D. L. Gorshanov V. V. Kouprianov I. A. Verestchagina 《Solar System Research》2010,44(1):68-80
We describe in detail the Apex I and Apex II software packages created for astrometric and photometric reductions of astronomical
observations with CCD cameras. The Apex I software package has been created for the semiautomatic reduction of astronomical
observations and has a convenient user interface. The Apex II software package allows for the completely automatic reduction
of astrometric and photometric observations to be performed. 相似文献
9.
I. A. Vereshchagina D. L. Gorshanov A. V. Devyatkin P. G. Papushev 《Solar System Research》2009,43(4):291-300
The results of photometric observations of (87) Sylvia, 2006 VV2, (90) Antiopa, and (39) Laetitia asteroids in 2006–2008 are presented. The specific features of light curves are considered for each object. In particular, for asteroid (87) Sylvia, possible mutual phenomena in this triple system are identified. Asteroid 2006 VV2 manifests a strong dependence of the light curve on the filter color, which testifies to the presence of inhomogeneities on its surface. The previously unknown brightness variation period with a duration of about three days was obtained for this asteroid. For binary asteroid (90) Antiopa, the strong dependence of its brightness on the phase angle was noticed; this may testify to the very flattened shape of its components. Considerable time variations of the shape of the light curve for asteroid (39) Laetitia may testify either to its complex shape or to its binary character. 相似文献
10.