Results of Photometric and Polarimetric Observations of the Fuor V1057 Cyg from the Time of an Outburst to the Present     

E. N. Kopatskaya  V. P. Grinin  D. N. Shakhovskoi  O. S. Shulov 《Astrophysics》2002,45(2):143-149

Observations of the brightness, color, and polarization of the fuor V1057 Cyg over more than 30 years are presented and briefly discussed. Variability of the linear polarization was found.  相似文献   

Study of radiative energy losses in the moving envelopes of T Tau stars     

V. P. Grinin  A. S. Mitskevich 《Astrophysics》1990,32(1):41-51

Crimean Astrophysical Observatory. Translated from Astrofizika, Vol. 32, No. 1, pp. 69–83, January–February, 1990.  相似文献   

Disk wind in young binaries and its impact on the infrared excesses of young stars     

V. P. Grinin 《Astronomy Reports》2002,46(5):380-389

We consider the effect of binarity of young stars on the spectral energy distribution of the IR radiation from circumstellar dust. The formation of a common dust envelope in a binary system with a low-mass secondary component is strongly affected by the disk wind from the secondary. The small velocities in peripheral areas of the wind are such that it can be partially or entirely captured by the primary, even when the distance between the components is up to several astronomical units. As a result, an envelope with a rather complex spatial and kinematic structure is formed. Its mass is many orders of magnitude smaller than that of the accretion disk around the binary. However, the thermal radiation emitted by dust particles of the envelope can be comparable to the total radiation of the accretion disk. This result is discussed in the context of the deficit at near-IR wavelengths (2–10µm) in current models for accretion disks around young stars.  相似文献   

Results of Photometric and Spectroscopic Observations of the Young Variable Star V730 Cep     

V. P. Grinin  K. A. Antonyuk  I. S. Potravnov  D. Mkrtichian 《Astronomy Letters》2018,44(12):798-802

We present the results of our photometric (V RI) and spectroscopic observations of the young variable star V730 Cep (MisV1147) classified by Uemura et al. (2004) as a Herbig Be star. Our photometry confirms the conclusion of the above authors that this star has a complex pattern of variability including periodic or quasi-periodic brightness variations with a period of about 14 days and deep Algol-like minima typical for UX Ori stars. Our spectroscopy shows that the classification of V730 Cep as a Herbig Be star is wrong. Actually, this star has a much lower temperature and belongs to the family of T Tauri stars. This allows us to explain the nature of the unusual photometric activity of V730 Cep based on a combination of two well-known models of variable circumstellar extinction applied to young stars: AA Tau- and UX Oritype variability. It follows from our observations that the color tracks on the V ?(V ?I) color–magnitude diagram for these models slightly differ: the AA Tau-type variability of circumstellar extinction is caused by larger grains than the UX Ori-type variability. Such a difference can be due to an increase in the characteristic sizes of circumstellar dust as the star is approached and has a simple explanation: small dust grains evaporate faster than large ones.  相似文献   

    

A. N. Rostopchina  V. P. Grinin  D. N. Shakhovskoi  A. A. Lomach  N. Kh. Minikulov 《Astronomy Reports》2007,51(10):869

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Formation of emission lines of hydrogen,calcium, and magnesium in expanding envelopes of T Tau stars     

V. P. Grinin  A. S. Mitskevich 《Astrophysics》1990,32(3):216-229

Crimean Astrophysical Observatory. Translated from Astrofizika, Vol. 32, No. 3, pp. 383–404, May–June, 1990.  相似文献   

Mechanism for cyclical activity of the Herbig Ae star BF Ori     

V. P. Grinin  A. N. Rostopchina  O. Yu. Barsunova  T. V. Demidova 《Astrophysics》2010,53(3):367-372

The photometric activity of the star BF Ori, which belongs to the family of UX Ori-type stars, is studied. New data obtained with the ASAS robotic telescope confirm the existence of a cyclical component in the light curve for this star with a duration of roughly 11-12 years. The form of the photometric cycle resembles the theoretical light curves for a young binary system with a low-mass secondary component, and which is accreting matter from a surrounding common disk. Alternative mechanisms for the cyclical variability of UX Ori stars are also discussed.  相似文献   

Hydrodynamic processes in young binaries as a source of cyclic variations in circumstellar extinction     

N. Ya. Sotnikova  V. P. Grinin 《Astronomy Letters》2007,33(9):594-603

Hydrodynamic models of a young binary accreting matter from the remnants of a protostellar cloud have been calculated by the SPH method. Periodic variations in column density in projection onto the primary component are shown to take place at low inclinations of the binary plane to the line of sight. These can result in periodic extinction variations accompanied by brightness variations in the primary. Generally, there can be three periodic components. The first component has a period equal to the orbital one and is attributable to the streams of matter penetrating into the inner regions of the binary. The second component has a period that is a factor of 5–8 longer than the orbital one and is related to the density waves generated in a circumbinary (CB) disk. Finally, the third, longest period is attributable to the precession of the inner CB disk regions. The relationship between the amplitudes of these cycles depends on the model parameters as well as on the inclination and orientation of the binary in space. We show that at a dust-togas ratio of 1: 100 and amass extinction coefficient of 250 cm² g^?1, the amplitude of the V-band brightness variations in the primary component can reach 1 ^m at a mass accretion rate onto the binary components of 10.8^?8 M _⊙ yr^?1 and a 10° inclination of the binary plane to the line of sight. We discuss possible applications of the model to young, pre-main-sequence stars.  相似文献   

“The photopolarimetric activity and circumstellar environment of the T tauri star CO ORI”     

A. N. Rostopchina  V. P. Grinin  D. N. Shakhovskoi  A. A. Lomach  N. Kh. Minikulov 《Astronomy Reports》2007,51(10):869

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Dust around young stars. Model of envelope of the Ae Herbig star WW Vul     

N. V. Voshchinnikov  V. P. Grinin 《Astrophysics》1991,34(2):84-95

Leningrad State University; Crimean Astrophysical Observatory. Translated from Astrofizika, Vol. 34, No. 2, pp. 181–198, March–April, 1991.  相似文献