Odessa Astronomical Publications最新文献

{"title":"DUAL HARD AND OPTICAL RADIATION DETECTORS FOR FAST NUCLEAR PROCESSES","authors":"Marko Doikov","doi":"10.18524/1810-4215.2022.35.268000","DOIUrl":"https://doi.org/10.18524/1810-4215.2022.35.268000","url":null,"abstract":"The registration and monitoring of rapid nuclear processes in degenerate plasma is a field of our consideration. The flows of hard and optic radiation are considered from outlying astrophysical and atmospheric objects. For their detecting it was suggested to use dual semiconductor type detectors. Simultaneous flow measurements allow obtaining high-precision positions and spectral properties of the objects under study. Due to the high energies of hard radiation and the nature of the nuclear processes, it is shown that the probability of their detection is high. In this case, the detector does not enter in saturation mode. At the other part of this detector optical matrix and reflection mirror are located. It is determined that the characteristics of useful signals are considered for the same instrumental function.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48264437","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"PROTOPLANETARY DISKS AROUND CLASSICAL T TAURI STARS","authors":"N. Ismailov, U. S. Valiev, N. S. Dzhalilov","doi":"10.18524/1810-4215.2022.35.268006","DOIUrl":"https://doi.org/10.18524/1810-4215.2022.35.268006","url":null,"abstract":"We have studied the energy distribution curves for a statistically significant number of classical T Tauri stars. It is shown that out of 49 stars, only 7 (14%) has I type of spectrum distribution, the rest belong to type II. Fundamental parameters, including the mass and age of objects are determined. It is shown that the amount of excess radiation in the far IR range increases with age. The change in mass with age, in contrast to Herbig's AeBe stars, exhibits a complex character.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45119944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"RT VIR – A SEMIREGULAR STAR WITH MASER EMISSION: MATHEMATICAL MODELLING OF OPTICAL VARIABILITY","authors":"L. S. Kudashkina, I. Andronov","doi":"10.18524/1810-4215.2022.35.268674","DOIUrl":"https://doi.org/10.18524/1810-4215.2022.35.268674","url":null,"abstract":"The historical light curve of the semiregular pulsating star RT Vir (SRb, Sp M8III) with a ma- \u0000ser emission is analyzed based on the AAVSO database. The star is extensively studied in the IR, radio and the optical ranges. The value of the period from the CCVS (155 d ) conflicts with some observational data. Signs of a systematic variability were also detected in the radio frequency range with a period that was close to 200 days. Studies of the period showed that the period of this star varies with time and the latest value was found to be roughly 136 days. Period analysis result of the visual data from 1904 May to 2016 August provided by AAVSO for RT Vir. Published databases of \"virtual observatories\" - AAVSOnet, Hipparcos, ASAS-SN, KWS were used. Periodogram analysis revealed that the star still has several periods (320, 280, 169 and 153 days). In fact, the variations are not truly periodic, there are large shifts in time, changes in amplitude, and these smaller periods occur as smaller-amplitude peaks in-between the main ones with 320 period. Two-color diagrams of gloss in I and color index (V-I) from V were constructed. Approximation of “Running parabola” was carried out, average values =8.457, =3.658, =+1.8 were determined.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44741206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SPECTROSCOPIC INVESTIGATIONS OF GALACTIC OPEN CLUSTER COLLINDER 394 – NEW RESULTS","authors":"I. Usenko, A. Kniazev, A. Miroshnichenko, S. Danford, V. Kovtyukh, T. Mishenina","doi":"10.18524/1810-4215.2021.34.244381","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244381","url":null,"abstract":"Confident main-sequence (MS) members of the Collinder 394 open cluster are perfect objects to check the correctness of their distances, obtained from the GAIA GR2 (2018) catalogue. The differences in the distances to the open cluster Collinder 394, determined by photometry and from the GAIA parallaxes have raised doubts about the correctness of the latter. Therefore we used spectroscopically determined T eff and loggvalues for these stars from Usenko et al. (2019) and tried to solve the inverse problem: determine radii of these stars using the derived distances and calibrations “T eff - radius” for MS stars and compare with similar ones. For this purpose we used the calibrations from Torres et al. (2010), based on the nearest MS eclipsing binaries and compilations for MS stars from Mamajek (2018). As a result, we obtained relationships that connect T eff , logg, radii, masses, and distances for the confident Collinder 394 MS stars. We have confirmed the correctness of the GAIA DR2 (2018) distances for these stars and determined their radii and masses. The latter estimates turned out to be close to those of the evolutionary masses calculated by the PARSEC model","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49386504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TYC5594-576-1: R-PROCESS ENRICHMENT METAL-POOR STAR","authors":"T. Mishenina, I. Usenko, A. Kniazev, V. Kovtyukh","doi":"10.18524/1810-4215.2021.34.244291","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244291","url":null,"abstract":"Atmospheric parameters and elemental abundances of metal-poor Population II star  TYC5594-576-1 ([Fe/H] = –2.8) have been studied, including the elements of neutron (n-) capture processes, as an important part of the enrichment sources of early Galaxy. Na, Mg, Al, Co, Sr, Y, Zr, Mo, Ba, La, Ce, Pr, Sm, Eu, Gd, Dy, Os, and Th abundances were determined using the synthetic spectrum method, taken into account the hyperfine structure (HFS) for the Ba II, La II and Eu II lines. The abundances of Si, Ca, Sc, N were determined based on the equivalent widths of their lines. The carbon abundance was obtained by the molecular synthesis fitting for the CH region of 4300-4330 ÅÅ. For the abundances determinations of C, Na, Mg, Al, Ba, and Th the NLTE corrections have been applied.We have determined the abundances of several n- capture elements for the first time and found that the behaviour of these elements abundances shows a significant trend with increasing atomic number. The elements ratios of [Eu/Fe] = 1.85, [Ba/Eu] = –1.24, [Sr/Ba] = –1.04 confirm the status of TYC5594-576-1 as a r-process enrichment star, with lower strontium [Sr/Fe] = –0.33 and higher thorium [Th/Fe] = 1.28 abundances. The obtained europium and thorium excesses testifies to the early enrichment of the Galaxy by the r-process elements as a result of the merger of neutron stars or black holes. The carbon abundance confirms the effect of canonical additional mixing in this star.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47730339","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"UPDATED CONSTRAINTS ON HEAVY RESONANCES USING THE RUN 2 DATA AT LHC","authors":"A. Pankov, I. A. Serenkova, V. Bednyakov","doi":"10.18524/1810-4215.2021.34.244250","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244250","url":null,"abstract":"The full ATLAS and CMS Run 2 data set at the Large Hadron Collider (LHC) with time- integrated luminosity of 139 fb −1 and 137 fb −1 , re- spectively, in the diboson channel is used to probe benchmark models with extended gauge sectors: theE 6 -motivated Grand Unification models, the left-right symmetric LR and the sequential standard model. These all predict neutral Z' and charged W' vector bosons, decaying into lepton or electroweak gauge boson pairs. We present constraints on the parameter space of the Z' and W' and compare them to those obtained from the previous analyses performed withLHC data collected at 7 and 8 TeV in Run 1 as well as at 13 TeV in Run 2 at time-integrated luminosity of 36.1 fb −1 . We show that proton-proton collision data at √ s = 13 TeV collected by the ATLAS and the CMS experiments allow to set the most stringent bounds to date on Z-Z' and W-W' mixing.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49499924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"THE POSIBILITY OF TRIPLE DETONATION IN WHITE DWARFS","authors":"D. Doikov, A. Yushchenko","doi":"10.18524/1810-4215.2021.34.244285","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244285","url":null,"abstract":"The induced γ-ray emissions are considered in contact cataclysmic binary systems with strong magnetic fields near white dwarfs and companion’s stars’ components. He-C-O atoms in white dwarf’s atmospheres collide with flows falling to poles as a magnetic column. Near white dwarf’s surface the falling flows with speed reaches 3 ∙ 10 6  m /s   and creates sufficient conditions for nuclear γ-radiation emission. The cross sections of nuclear γ-radiation emission are presented in 0.1 – 150 MeV energy intervals depending on the colliding atoms and particles. The mass loss from binary components is of the order of   ̇ ≈ (10 −11 − 10 −7 )Msun. We considered the collisions of p – He, α – He, p – C, α – C, p – N, α – N, p – O, α – O, C – He, C – C, C – N, C – O, N – He, N – C, N – N, N – O, O – He, O – C, O – N, and O – O types. Monochromatic energy luminosities Lγ in the above energy intervals for different modes in cataclysmic systems were calculated taking into account the loss of mass M , chemical composition and dynamics of fluxes incident on the magnetic poles. We found the dependencies between   Lγ    and chemical composition and calibrated the synthetic γ-spectra in the above pointed energy intervals. It has been concluded that power flyers are detected from p-p detonation in surface layers in white dwarf’s atmospheres. From calculation we estimated that p-p detonation time scale is in frame of the 0.07-0.1 sec. From which it is concluded that in some surface p-p explosions in the column of the magnetic field are produce significant number of positrons who has a sufficient probability to inject beyond the atmosphere of a white dwarf. It has been shown that the induce γ-ray spectroscopy together with positron spectroscopy are opens new possibilities for diagnostics of the flayers in AM Her polar system. The mechanism of triple detonation, which leads to the explosion of type I supernovae, is proposed. In this context, it is assumed that SN I type explosions occur in white dwarfs with masses not reaching the Chandrasekhar limit. The neutron formation in the matter that are in an explosive state after p-p detonation is considered separately.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47388446","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OBSERVATION CONTROL DEVICE FOR THE URAN-4 DECAMETER RADIO TELESCOPE","authors":"V. Galanin, V.G. Komendant, V.V. Yasinski","doi":"10.18524/1810-4215.2021.34.244382","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244382","url":null,"abstract":"The URAN-4 radio telescope has been operating at the Odessa Radio Astronomy Observatory of the Radio Institute of the National Academy of Sciences of Ukraine since 1986. The telescope is an element of a decameter long-base interferometer – the radio telescopes which are located across the territory of Ukraine from west to east. The URAN-4 consists of antenna and upgraded radiometer. Antenna consists of 128–element with phased array with dimensions of 232.5 x 22.5 m. The telescope operates in the 10 – 30 MHz range. Its receiving equipment is capable of separating two polarization components of the received signal. The radiation pattern of the radio telescope is 2,7x22 degrees at 25 MHz. The resolution of 2 seconds is realized in the interferometer mode. The instrumental complex of the radio telescope includes the upgraded device for controlling its operation. This device is made in the form of a separate unit. The ATMEL AT90S8515 microcontroller with registers and a communication circuit between the unit and the computer are mounted in it. The discrete movement in space of the antenna's directional pattern and sets the required attenuation in the attenuator during calibration are carried out with the upgraded controlling device at a given time during the observation period. The controlling device also allows adjust the current time of the computer using GPS.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45473468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"OBTAINING NEUTRON MATTER AND HYPERHEAVY NUCLEI: POSSIBLE QUANTUM-TECHNOLOGICAL INSTRUMENTAL APPROACHES","authors":"G. Ryazantsev, V. Vysotskii, G. K. Lavrenchenko, S. S. Nedovesov","doi":"10.18524/1810-4215.2021.34.244251","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244251","url":null,"abstract":"Possible mechanisms of creation of both hyperheavy nuclei by electron-nuclear collapse and              neutron matter by condensation of ultracold neutrons are discussed. The fundamental possibility of the existence of  such objects was previously substantiated by A.B.Migdal, who suggested that the known set of proton-neutron nuclei with mass numbers from 0 to 300 and a maximum specific binding energy of about 8 MeV / nucleon at A≈60 corresponds to the first region, beyond which (starting from about the charge Z≈ ( hc/e2 )3/2 ≈1600 ) there is an additional region describing a possible state of nuclear matter, stabilized by a pion condensate. In this region, the maximum specific energy corresponds to ≈15 MeV / nucleon at A ≈ 100000. It is shown that neutron matter can be obtained under certain conditions, and its systematization can be realized as an addition to the Periodic Table. When solving such problems, it becomes quite real to study not only physical, but also chemical, and possibly engineering and technical properties. Analysis shows that the stability of neutron matter at the microlevel is ensured by the Tamm interaction and the Hund beta equilibrium. Such matter can be quite stable    not only on the mega-level (neutron stars) due to gravitational interaction, as was a priori assumed earlier, but also on the scale of \"ordinary\" matter. The process of neutronization is possible not only with critical gravitational interaction, but also by other mechanisms (supercritical increase in the atomic number of elements due to electron-nuclear collapse and condensation of ultracold neutrons), which opens the way to the fundamental possibility of obtaining both neutron matter in laboratory conditions and superheavy nuclei. Based on the works of Migdal, Tamm and Hund, the possibility of the existence of stable neutron matter (with Z >> 175, N >> Z, A> 10 3 -10 5 and a size of 200-300 femtometers and more) is argued at the microlevel, and not only at the mega-level, as is now considered in astrophysics. A critical analysis of the well-established concept of the minimum possible mass of neutron stars is carried out. The following quantum technological approaches to the realization of UCN condensation are proposed: 1. Slow isothermal compression; 2. Refrigerator for dissolving helium-3 and helium-4; 3. Use of a conical concentrator for UCN focusing (Vysotskii cone); 4. Magnetic trap; 5. Additional UCN laser cooling. Neutron matter is considered as a potential cosmological candidate for dark matter. One should take into account the possibility of the formation of fragments of neutron matter as dark matter (neutral, femto-, pico- and nanoscale, the cooling of relics makes it difficult to detect them by now) already at the initial origin of the Universe, which is the dominant process. The observable part of the Universe is formed by the residual part of protons, and then by decayed single neutrons and unstable fragments of neutron matter (with Z> 175, N ","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46056059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"APPLICATION OF PHOTOMETRY TO UNDERSTAND THE BEHAVIOUR OF GEOSTATIONARY OBJECTS ON ORBIT","authors":"P. Sukhov, V. Yepishev, I. Motrunich, K. Sukhov","doi":"10.18524/1810-4215.2021.34.244335","DOIUrl":"https://doi.org/10.18524/1810-4215.2021.34.244335","url":null,"abstract":"One of the challenges of satellite characterization is the ability to not only determine the spacecraft or-bit, but also satellite operating status, orientation, size, bus type, and material properties. Positional observations allow us to determine and/or update orbital elements of satellites, but they do not afford an insight into the behaviour of a satellite in orbit. The article discusses the results of solving the inverse problem of astrophysics. How you can use photometric, astrometric information about a satellite, its lighting conditions, supplemented by additional information, to understand the behavior of a satellite in orbit. The results are shown using examples of four satellites in geostationary orbit. An algorithm for calculating the photometric and dynamic characteristics of geostationary objects is provided.","PeriodicalId":34039,"journal":{"name":"Odessa Astronomical Publications","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46882964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}