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Here you would find a brief summary of the most important results of scientific research carried out by our researchers during the last year, presented by the observatory to the Department of Physical Sciences of the RAS.
Archive of achievements, Solar system sector
Galaxy
Image of a White Dwarf in the CH Cygnus Binary.
Using speckle interferometry on the BTA, we for the first time obtained
an image of an accreting white dwarf in an unusual symbiotic binary óî Cyg.
From the measurements of the angular separation between the components
of the pair (0.042") and the brightness difference (2m),
we determined the period of orbital movement, 15.6 years, and the
component masses:
2.0 M
for the red giant, and
0.7 M
for the white dwarf. We found that the collimated gas outflow from the
system does not coincide with the orbit surface normal of the binary.
(For contacts: Yu.Yu.Balega)
New Wolf-Rayet Type Star.
A new nitrogen sequence Wolf-Rayet Star was discovered. It belongs to the
rare subtype, intermediate between the LBV and WR, in the winds of which
the hydrogen is still present. The star is located at the centre of a
ring IR nebula with the diameter of 2pc. We determined the star's
parameters: ô=40kK, its shell has only 20% of hydrogen, Av=7.4m,
lgL/L=5.3,
mass los rate
10-4.7M
a year, distance 4.2kpc. It was discovered that the peculiar velocity
of the star is about 50km/s, and that it was discarded from a young star
cluster.
In collaboration with SAI MSU, the University of Potsdam and the
University of Bochum (Germany).
(For contacts: Fabrika S.N.)
Magnetic fields of Chemically Peculiar Stars.
Based on the observational data from the 6-m telescope and from other
sources, it was shown with high reliability that chemically peculiar
stars with strong depressions in their continuum energy distributions
possess the magnetic fields and rotation periods 2 and 3 times larger,
respectively, than the stars with weak depressions. This is an additional
evidence for the fact that slow rotation of a star is an important factor,
contributing to the formation of the phenomenon of magnetic chemically
peculiar stars.
(For contacts: Romanuyk I.I.)
Radio Flare Maxima Drift in LSI+61d303 Microquasar.
Comparing the RATAN-600 2003 and 2009 observations of the LSI+61d303
microquasar light curves within 5 and 6 orbital periods (P=26.5d),
it was discovered that the mean flare maxima over a period took place at
the orbital period phases
0.50
0.05 and
0.700.05, taken the superorbital
period phases of (P=1667d) 0.65 and 0.0, respectively. In both
sets the maxima arrived later at low frequencies. The reason of synchrotron
emission modulation by the superorbital period is, possibly, a precession
of jet ejections.
(For contacts: S.A.Trushkin)
Archive of achievements, Galaxy sector
Metagalaxy
New Nearby Dwarf Galaxy with Low Metallicity.
It was discovered that the interstellar medium of the SDSS J0926+3343
dwarf galaxy, located in the nearby Lynx-Cancer Void, has the metal
abundance 35 times lower than the solar one - the lowest value between
thousands of known galaxies inside the sphere with the radius of 20Mpc.
The age of visible old stellar population is from 1 to 3 Gyr. In the same
void there is a similar galaxy DDO68, which points at the existence of
the regions in the local Universe, where the formation and evolution of
galaxies may take place with a long delay.
In collaboration with the South-African Observatory and the Observatoire
de Paris.
(For contacts: Pustilnik S.A.)
Archive of achievements, Metagalaxy sector
Hardware and methodological developments
Development of an Astrophysical Facility for the Studies of Fast
Variable Processes.
We finalized the development of a facility for observations (including
remote observations) of the star-shaped objects with the temporal
resolution of 1 micro second. The facility is featuring a multimode
panoramic photospectropolarimeter, 1 or 2 coordinate-sensitive quanta
detectors and a four-computer measurement control and registration system.
Observational modes: photometric in the UBVR colour bands, spectral
(50 or 10 nm per pixel), photopolarimetric and spectropolarimetric
in 2 or 4 polarisation planes.
(For contacts: G.M.Beskin)
RATAN-600 Multi-Octave Frequency Range Overlapping Finalized.
We finalized the multi-octave overlapping of the RATAN-600 frequency range
from 0.75 to 18GHz with the frequency resolution of 1% using the parallel
spectrum analysing complex. In combination with large effective area,
the RATAN-600 offers new opportunities of studying the thin structure
of the solar corona radio emission. We have implemented the registration
of the instantaneous spectra throughout the entire frequency range.
Regular observations of the Sun go through an automated reduction and
are available at
http://www.spbf.sao.ru/prognoz/
within 4 minutes from the acquisition time.
(For contacts: V.M.Bogod)
Archive of achievements, Hardware and Methodological Development sector
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