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1.
G. M. Karataeva V. A. Yakovleva V. A. Hagen-Thorn O. V. Mikolaichuk 《Astronomy Letters》2001,27(2):74-80
We analyze our BVR c photometry for UGC 5600, a candidate polar ring galaxy, obtained with the 6-m telescope. We have confirmed the existence of an inner polar ring and show that the outer ring-shaped structure represents spiral arms; i.e., UGC 5600 belongs to the rare class of gas-rich spiral galaxies with inner polar rings. 相似文献
2.
We analyze multicolor observations of the blazar ON 231 obtained during coordinated observations in 1994–2002. On average, the spectral energy distribution of the variable component in the optical range remains constant, and can be represented
by the power law F
ν ∼ ν
−0.85. Since the radiation of the blazar is strongly polarized, there is no doubt that the variable emission that is responsible
for the activity of the blazar is synchrotron radiation. There are small but significant season-to-season variations in the
spectral index. 相似文献
3.
V. A. Hagen-Thorn A. V. Hagen-Thorn S. G. Jorstad L. O. Takalo A. Sillanpää T. Pursimo P. Boltwood 《Astrophysics》2001,44(3):283-291
The results of multicolor observations of the blazar 3C 66A, obtained in the course of the project OJ-94, are analyzed. It is established that the energy distribution of the variable source in the optical and IR ranges can be represented, on the average, by a power law: F -0.92. Since the blazar's emission is strongly polarized, there is no doubt of the synchrotron nature of the variable source responsible for the blazar's activity. 相似文献
4.
The Pulkovo Spectrophotometric Data Base is used to determine the expansion velocities and radii of the continuum emission
layers of the stars RR SCO and OMICR CET. Dependences of the radii and velocities on the phase of the variability cycle are
found which agree with the known values obtained from the layers which emit line radiation.
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Translated from Astrofizika, Vol. 50, No. 4, pp. 557–564 (November 2007). 相似文献
5.
Leningrad State University, Udmurtsk State University. Translated fromAstrofizika, Vol. 25, No. 1, pp. 77–83, July–August, 1991. 相似文献
6.
E. V. Ruban G. A. Alekseeva A. A. Arkharov E. I. Hagen-Thorn V. D. Galkin I. N. Nikanorova V. V. Novikov V. P. Pakhomov T. Yu. Puzakova 《Astronomy Letters》2006,32(9):604-607
We present the results of our visual and near-infrared spectrophotometric observations for 77 variable stars obtained during 1971–1991 in Chile, Armenia, and Bolivia. The quasi-monochromatic, extraatmospheric fluxes from the stars are given in absolute energy units (W m?2 m?1) at all wavelengths of the spectral range at 2.5-nm intervals. 相似文献
7.
Optical light curves of three blazars are analyzed by Hurst’s method of normalized range. It is shown that Hurst’s empirical
relationship is satisfied for these curves, in accordance with which the Hurst parameters are found for each curve. Assuming
that blazar light curves have self-affinity, they determine the fractal dimensionality of the curves to be D ≈ 1.1.
Translated from Astrofizika, Vol. 40, No. 3, pp. 341–348, August, 1997. 相似文献
8.
9.
This is a study of photometric data from the Hipparcos catalog and spectrophotometric observations by a group of Pulkovo observers
in Bolivia of the variable star 2 Cen (V806 Cen). Fourier analysis yields a more precise value of 12.57 d for the period of
the brightness variation instead of 12.0 d. Light curves constructed from the photometric data are found to have a smooth
systematic variation with an amplitude on the order of 0m.2. Short duration changes in the brightness by 0m.1 take place over times of a few hours. The differences in the temperature and radius of the emitting layer at maximum and
minimum brightness, which occur at phases of 0.00 and 0.58, respectively, are found. At the maximum the radius was smaller
by 6% and the temperature was higher by 70 K; these differences may characterize the star’s pulsations. 相似文献
10.
Hagen-Thorn V. A. Troitskaya Yu. V. Hagen-Thorn E. I. Troitsky I. S. Savchenko S. S. Arharov A. A. Efimova N. V. Klimanov S. K. Volkov E. V. 《Astronomy Reports》2019,63(5):378-390
The results of multicolor photometric and polarization observations of the blazar 4C 38.41 (Q 1633+382) performed at St. Petersburg State University, the Pulkovo Astronomical Observatory of the Russian Academy of Sciences, Boston University, and Steward Observatory in 2006–2017 are analyzed. Separate variable sources responsible for the observed activity are distinguished, whose power-lawspectra and high degree of polarization confirm their synchrotron nature. The observed color variability of the object (redder when brighter) can be explained by an increase in the contribution to the total emission of a red component with variable flux and a constant relative spectral energy distribution. A close correlation between the optical and gamma-ray light curves is identified, suggesting the same location of the variable sources responsible for the radiation in these bands.
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