Search Publications
The OSACA database and a kinematic analysis of stars in the solar neighborhood
Bobylev, V. V.; Bajkova, A. T.; Goncharov, G. A.
We transformed radial velocities compiled from more than 1400 published sources, including the Geneva-Copenhagen survey of the solar neighborhood (CORAVEL-CfA), into a uniform system based on the radial velocities of 854 standard stars in our list. This enabled us to calculate the average weighted radial velocities for more than 25000 HIPPARCOS st…
Stellar structure of irregular galaxies: Edge-on galaxies
Tikhonov, N. A.
Stellar photometry obtained using the Hubble Space Telescope is used to study the distributions of the number densities of stars of various ages in 12 irregular and dwarf spiral galaxies viewed edge-on. Two subsystems can be distinguished in all the galaxies: a thin disk comprised of young stars and a thick disk containing a large fraction of old …
The Stellar Structure of Irregular Galaxies. Face-on Galaxies
Tikhonov, N. A.
Stellar photometry of nearby irregular galaxies of the Local Group is used to identify and study the young and old stellar populations of these galaxies. An analysis of the spatial distributions of stars of different ages in face-on galaxies shows that the young stellar populations in irregular galaxies are concentrated toward the center, and form…
Turbulence in the Inner Solar Wind Determined from Frequency Fluctuations of the Downlink Signals from the ULYSSES and GALILEO Spacecraft
Plettemeier, D.; Bird, M. K.; Efimov, A. I. +2 more
The results of several sets of measurements of the frequency of radio signals during coronal-sounding experiments carried out from 1991 to 2000 using the ULYSSES and GALILEO spacecraft are presented and analyzed. The S-band signals (carrier frequency f = 2295 MHz) were received at the three 70-m widely spaced ground stations of the NASA Deep Space…
Large-scale activity in solar eruptive events of October November 2003 observed from SOHO/EIT data
Grechnev, V. V.; Chertok, I. M.
Large-scale solar disturbances associated with powerful flares and coronal mass ejections (CMEs) during two passages of a grand system of three active regions in October November 2003 are analyzed using data obtained with the SOHO/EIT EUV telescope. Dimmings (transient coronal holes) and, to a lesser extent, coronal waves (traveling emitting front…
A Spectroscopic and Photometric Study of NGC 2685, the Prototype Polar-Ring Galaxy
Moiseev, A. V.; Burenkov, A. N.; Hagen-Thorn, V. A. +3 more
We present and analyze spectroscopic and photometric observations for NGC 2685, the prototype polar-ring galaxy. The spectroscopic data were acquired using the 6 m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences with the UAGS spectrograph and a scanning Fabry-Perot interferometer, while the photometric analysi…
Polarimetry of the Protoplanetary Nebula AFGL 2688
Miroshnichenko, A. S.; Klochkova, V. G.; Panchuk, V. E. +1 more
Our spectroscopic (with resolution R=75 000) and spectropolarimetric (R=15 000) observations with the 6-m telescope of the Special Astrophysical Observatory have enabled us to distinguish photospheric and circumstellar features in the optical spectrum of the bipolar protoplanetary nebula AFGL 2688 for the first time. The linear polarization of the…
Analysis of a Solar Eruptive Event on November 4, 2001, Using CORONAS-F/SPIRIT Data
Grechnev, V. V.; Chertok, I. M.; Kuzin, S. V. +5 more
We analyze large-scale solar activity following the eruption of a very powerful, geoeffective coronal mass ejection in the 23rd solar cycle, observed at 175, 284, and 304 Å on November 4, 2001, using data from the CORONAS-F/SPIRIT telescope. In particular, we have shown that the restructuring of the magnetic field above the eruption center was acc…
Chemical Composition of 15 Photometric Analogues of the Sun
Galazutdinov, G. A.; Bikmaev, I. F.; Galeev, A. I. +1 more
The results of a spectroscopic analysis of 15 stars that are photometric analogues of the Sun are reported. The effective temperatures and surface gravities in the stellar atmospheres are derived from published photometric indices and the HIPPARCOS parallaxes. The abundances of 33 elements ranging from lithium to europium are analyzed based on hig…
Proper Motions of Open Star Clusters and the Rotation Rate of the Galaxy
Beshenov, G. V.; Loktin, A. V.
The mean proper motions of 167 Galactic open clusters with radial-velocity measurements are computed from the data of the Tycho-2 catalog using kinematic and photometric cluster membership criteria. The resulting catalog is compared to the results of other studies. The new proper motions are used to infer the Galactic rotation rate at the solar ci…