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Achieving Record Resolution in Optical Astronomy by Observing Occultations
of Stars by Asteroids
Observations of the occultation of the binary TYC 1947-290-1 by the asteroid
(87) Sylvia at the 6-m BTA SAO RAS telescope made it possible to determine
the diameter of the main component and set the upper limit for of the
secondary. The measured angular values of the diameters of the TYC
1947-290-1 pair were 52 microseconds of arc for the bright
(Vmag = 11.4) component and 31 microseconds as the upper
resolution limit for the weak (Vmag = 12.1). Successful
observations of the occultation by an asteroid in order to determine
the angular diameter of the star were performed for the second time
(the first by Benbow et al., 2019), with an optical telescope -for the
first time. The obtained angular resolution is a record in the optical
range and is comparable to the capabilities of modern radio interferometric
complexes.
Our work has shown that observations of stellar occultations by asteroids
can be used to measure angular sizes at a level of up to ≈30
microseconds of arc using single telescopes. This is tens of times better
than the resolution of modern long-base interferometers in the visible
and IR ranges and by three orders better than the diffraction limit of
the largest optical telescopes.
Within the framework of the RFBR grant No. 20-32-70120 "Measurement
of fundamental parameters of stars by high angular resolution methods."
Authors:
Dyachenko V.V., Balega Yu.Yu., Beskakotov A.S., Maksimov A.F.,
Mitrofanova A.A. (SAO RAS) in cooperation with Richichi A. (INAF),
Obolentseva M. (SPBU)
Published:
1. Dyachenko V., Richichi A., Obolentseva M., Beskakotov A., Maksimov A.,
Mitrofanova A., Balega Y., A joint occultation and speckle investigation
of the binary star TYC 1947-290-1 and of the asteroid (87) Sylvia, 2021,
Monthly Notices of the Royal Astronomical Society, 508(2), 2730-2735
High Temporal Resolution Multimode Panoramic Photospectropolarimeter (MPPP)
The modernization of the instruments and software complex of the MANIA
experiment for searching for and studying the variability of astrophysical
objects with a temporal resolution of 10-6 s has been completed,
the main component of which is the MPPP panoramic photopolarimeter
which has no analogues in the world. As radiation receivers, two position
sensitive detectors (PSDs) are used with the maximum sensitivity in
the short-wave and long-wave regions of the spectrum (Debur et al., 2003;
Plokhotnichenko et al., 2020) with the determination of the moments of
detection of quanta by chronometric devices "Quantochron 4-48"
(Plohotnichenko et al., 2009), as well as the EMCCD camera. The complex
provides observations in the following 5 modes (with synchronous measurement
of 3 Stokes parameters, if necessary): the broadband photometry with
PSD and/or the EMCCD camera, synchronous UBVR photometry, spectroscopy
with the Abbe prism (5 resolution elements), spectroscopy with the
diffraction grating (50 resolution elements).
They are changed remotely in 1-5 minutes, and the detection, storage, and
reduction of data is provided by an information cluster consisting of 7
computers, which allows continuous recording photon fluxes throughout
the night with an accuracy of 0.1 ?s to UT. The results obtained during
observations of X-ray sources, flaring stars, and optical pulsars
demonstrate the efficiency of using the created complex in the high
temporal resolution astronomy and relativistic astrophysics.
Authors:
Plokhotnichenko V.L.,
Moiseev S.V., Shergin V.S.,
Gorodovoy E.P., Gutaev A.G. (SAO RAS) in cooperation with Beskin G.M.
(SAO RAS, KFU), Karpov S.V. (SAO RAS, Institute of Physics, Czech Academy
of Sciences), V.G. de Bur (A.F. Ioffe Physical-Technical Institute of the
Russian Academy of Sciences) , Solin A.V., Solin A.A. (BSU Institute
for Nuclear Problems, Belorus), Lyubetskaya Z.V., Lyubetskiy A.P.
(LLC "Engineering Bureau TSEVLAP", Pavlova V.V. ( Rostov-on-Don),
Moiseev S.S. (IE Moiseev), Badin D.A. (SAI MSU, Dukhov Automatics Research
Institute (VNIIA) , Plokhotnichenko P.V. (Service center Rus Lcd)
Published:
1. Plokhotnichenko V.L., Beskin G.M., V.G. de Bur, Karpov S.V., Moiseev S.V.,
Shergin V.S., Gorodovoy E.P., Gutaev A.G., Solin A.V., Solin A.A.,
Lyubetskaya Z.V., Lyubetskiy A.P., Pavlova V.V., Moiseev S.S., Badin D.A.,
Plokhotnichenko P.V., High Temporal Resolution Multimode Panoramic
Photospectropolarimeter, Astrophysical Bulletin, 2021, Volume 76, No. 4,
p. 558-576.
Interactive catalog of blazar measurements at RATAN-600
In 2021, an interactive catalog of multifrequency (1.1-22.3 GHz) measurements
of blazars at the RATAN-600 was developed: "RATAN-600 multi-frequency
catalog of blazars". The catalog is hosted in
www.sao.ru/blcat
and is a modernized version of the electronic catalog of BL Lacertae
objects (Mingaliev et al., 2014). The new catalog contains all types
of blazars (blazars, flat-spectrum quasars, and blazars of an undetermined
type) from the BZCAT blazar catalog (Massaro et al., 2009) and includes
measurements of more than 1600 objects. The catalog contains the radio
spectra and light curves of blazars obtained with the RATAN-600 SAO RAS
in 2004-2021; measurements in the radio continuum from external sources
connected from the CATS and NED databases are available for export.
Basic information about objects (the coordinates, redshifts, blazar type,
magnitude, and radio luminosity) is presented in the main table. Radio
luminosities, spectral and variability indices, statistics on the main
parameters of the sample are interactively calculated and available for
export; objects with a radio emission variability of 200% at a frequency
of 11 GHz on a scale of two years are indicated. The catalog is
systematically updated with new measurements and is an effective tool
for studying the statistical properties of large samples of
blazars and for studying individual objects using long-term light curves.
Authors:
Sotnikova Yu.V., Mufakharov T.V., Mingaliev M.G., Udovitskiy R.Yu.,
Semenova T.A., Erkenov A.K., Bursov N.N., Mikhailov A.G. (SAO RAS)
Published:
1. Mufakharov T., Sotnikova Y., et al., The RATAN-600 multi-frequency
catalogue of blazars, 2021, MNRAS, submitted
2. Sotnikova Yu., Udovitsky R., Mufakharov T., state registration of the
database "RATAN-600 multi-frequency data for blazars, edition 1.3",
Certificate No. 2021621910 dated 09.09.2021.
3. Sotnikova Yu., Mufakharov T., Udovitsky R. et al., Filing of an
international application for the invention "Method of compiling a catalog
of measurements of radio emission parameters of
blazars", Application No. PCT/RU2021/000473 dated 29.10.2021.
4. Mingaliev M., Sotnikova Yu., Udovitskiy R., et al., RATAN-600
multi-frequency data for the BL Lacertae objects, Astronomy & Astrophysics,
572, id.A59, 4 pp., 2014.
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