Astronomy Reports最新文献

{"title":"Activity of TOI-3568 and Mass Loss of the Atmosphere of Its Exoplanet in the Sub-Jovian Desert","authors":"I. S. Savanov","doi":"10.1134/S1063772925701379","DOIUrl":"10.1134/S1063772925701379","url":null,"abstract":"<p>The properties of the TOI-3568 system, which has a super-Neptune-type planet and which by its properties falls into the region of the sub-Jovian desert, have been considered. TOI-3568 is a poorly studied dwarf of the spectral class K. Based on archival measurements of the brightness of TOI-3568 (Kamogata Wide-field Survey), the possible cyclic long-term variability of the object equal to 1.3, 1.7 and 4.1 years has been estimated. It has been found that TOI-3568 belongs to the number of old stars and can have only moderate or low activity. The mass loss from the planet’s atmosphere has been calculated using an approximation formula for the atmosphere loss model with an energy limitation. If the star is a low-activity K dwarf then <span>({{M}_{{{text{loss}}}}})</span> can be <span>(1.18 times {{10}^{9}})</span> g/s. If the star’s activity approaches the maximum for stars of this spectral class then the value of <span>({{M}_{{{text{loss}}}}})</span> will increase in 6.3 times. Our data are in an agreement with the results characterizing the general behavior of parameter <span>({{M}_{{{text{loss}}}}})</span> for other objects, including the hot Jupiter HD 189733 b and the warm Neptune GJ 436 b. The TOI-3568 system is of particular interest because it has made it possible to study rare objects located on the “mass-period” or “radius-period” diagrams of exoplanets in the region that covers the range between super-Earths and hot Jupiters (called the sub-Jovian desert) and which exhibits a deficit in the number of planets. The fact that TOI-3568 is an old star has provided a unique opportunity to trace the evolution of the properties of a planetary system currently located in the sub-Jovian desert.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1437 - 1441"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Possibility of Observing Photon Rings Using High-Frequency Space Radio Interferometry with Very Long Bases","authors":"A. G. Rudnitskiy,&nbsp;M. A. Shchurov,&nbsp;A. V. Khudchenko,&nbsp;T. A. Syachina","doi":"10.1134/S1063772925701380","DOIUrl":"10.1134/S1063772925701380","url":null,"abstract":"<p>In the paper, the possibility of observing photon rings in the close vicinity of supermassive black holes using space very long baseline radio interferometry at a frequency of 600 GHz has been examined. The 600-GHz range is promising for such observations by very long baseline radio interferometry because high frequency reduces the contribution of radio emission scattering by the interstellar medium and also makes it possible to increase the angular resolution of the interferometer. High angular resolution and low scattering, in turn, have suggested the possible detection of photon rings in the close vicinity of supermassive black holes. To estimate these possibilities, modeling of the visibility amplitude distribution from the baseline projection has been performed, taking into account various possible sensitivity parameters of the interferometer. Based on the results, the prospects for the 600-GHz range in terms of observing photon rings have been shown. In addition, the requirements for the on-board receiving complex of a space interferometer have been formulated, at which detection of photon rings is feasible.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1442 - 1448"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621767","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spectroscopic Binary Cepheid AU Peg in the Gaia DR3 Epoch: Effect of Ellipsoidality, Mass, and Evolutionary Status","authors":"A. S. Rastorguev,&nbsp;M. V. Zabolotskikh,&nbsp;N. A. Gorynya","doi":"10.1134/S1063772925701409","DOIUrl":"10.1134/S1063772925701409","url":null,"abstract":"<p>The physical characteristics and evolutionary status of the spectroscopic binary Cepheid AU Peg, usually classified as a BL Her variable, is revised. Taking into account previously unpublished radial velocity measurements made with a radial velocity meter (RVM), the parameters of the relative orbit of the Cepheid and its companion are refined. Based on the available radial velocity measurements and photometric observations, a number of estimates of the Cepheid’s pulsating radius are made. Based on 74 new radial velocity measurements made in the period JD2453930–2459490 virtually simultaneously with the Gaia DR3 photometric observations (44 brightness measurements in the period JD256962–2457877), the mean radius of AU Peg is determined by the pulsating photosphere method equal to (16.0 ± 0.6) <span>({{R}_{ odot }})</span>; the amplitude of radius variations is about 0.7 <span>({{R}_{ odot }})</span>. For the first time, 2% brightness variations are found for a spectroscopic binary Cepheid in the G band with a half orbital period, the phases of which are clearly synchronized with the phases of the orbital motion (conjunctions and quadratures) and can be interpreted as a manifestation of the ellipsoidality effect of the main component filling the Roche sphere at 60–70%. The orbit of the binary system calculated on the basis of astrometric data from Gaia DR3 and radial velocities is limited by a torus with a thickness of |<i>z</i>| ≤ 300 pc and inner and outer radii equal to 7.2 and 8.8 kpc, respectively, while the vertical velocity lies within |<i>V</i>_<i>z</i>| ≤ 18 km/s. Based on the kinematics and abundance of heavy elements, AU Peg can certainly be classified as a representative of the typical population of a thin disk of moderate (∼1–3 Gyr) age, which completely excludes its classification as a BL Her variable. The Cepheid, which current mass, as follows from the magnitude of ellipsoidality, does not exceed ∼(0.85 ± 0.05) <span>({{M}_{ odot }})</span>, is at the evolutionary stage after the mass exchange in the subgiant phase with a companion - a main-sequence star, which is currently significantly more massive than the Cepheid.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1457 - 1469"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Search for Interpulses in a Complete Sample of Pulsars at a Frequency of 111 MHz","authors":"M. O. Toropov,&nbsp;S. A. Tyul’bashev,&nbsp;V. S. Beskin","doi":"10.1134/S1063772924701026","DOIUrl":"10.1134/S1063772924701026","url":null,"abstract":"<p>An interpulse search has been carried out in a sample of 96 pulsars observed on the Large Phased Array (LPA) radio telescope in the Pushchino Multibeams Pulsar Search (PUMPS). The pulsar sample has been complete for pulsars having a signal-to-noise ratio (<span>(S{text{/}}N)</span>) in the main pulse (MP) greater than 40. To search for weak interpulses (IP), the addition of average profiles over an interval of up to 10 years has been used. Interpulses have been detected in 12 pulsars (12.5% of the sample), of which 7 pulsars have an interpulse located near the <span>(180^circ )</span> phase relative to the main pulse (probable orthogonal rotators), and 5 have had phases far from <span>(180^circ )</span> (probable coaxial rotators). The amplitude ratios of IP/MP have been in the range of 0.004‒0.023, the median value is 0.01. Estimates of the observed number of coaxial and orthogonal rotators with IP/MP of <span>({kern 1pt} geqslant {kern 1pt} 0.01)</span> have not contradicted the model according to which, during evolution, the magnetic axis and the rotation axis become orthogonal.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1191 - 1198"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143622074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Difference in Gravitational Potentials at Two Ground Points Measuring Experiment Using the Duplex Satellite Method","authors":"A. V. Naumov,&nbsp;F. R. Smirnov,&nbsp;V. F. Fateev","doi":"10.1134/S106377292570132X","DOIUrl":"10.1134/S106377292570132X","url":null,"abstract":"<p>An experiment on measuring the difference in gravitational potentials and orthometric heights of two ground points using a quantum clock and a duplex satellite communication method was conducted for the first time in the Russian Federation. The measurement points were located in the territory of the Federal State Unitary Enterprise “VNIIFTRI” at a distance of 850 m from each other with a height difference of about 21 m. The Russian geostationary satellite Express-80 was used as a repeater, duplex communication was established using stationary and relocatable sets of duplex equipment. The difference in orthometric heights was measured with an accuracy of about 2.8 m.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1376 - 1384"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621829","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Search for Pulsars with Periods of More Than Two Seconds at Declinations from +21° to +42°","authors":"S. A. Tyul’bashev,&nbsp;G. E. Tyul’basheva","doi":"10.1134/S1063772924701038","DOIUrl":"10.1134/S1063772924701038","url":null,"abstract":"<p>The search for long period transients with periods (<span>(P)</span>) from 2 to 90 s was carried out in daily observations conducted in an area of 6300 sq. deg. The data was obtained using a Large Phased Array (LPA) at a frequency of 111 MHz. Periodograms calculated using the Fast Folding Algorithm (FFA) were used for the search. To increase the sensitivity, the periodograms obtained in different observation sessions were added. Of the 14 known pulsars that entered the study area, having periods of <span>(P &gt; 2)</span> s and dispersion measures (<span>(DM)</span>) less than 200 pc/cm³, nine were detected. Two new pulsars were found. The average profiles of pulsars are obtained and estimates of their flux density are given. Discovered pulsar J1951+28 with a period of <span>(P = 7.3342)</span> s and <span>(DM)</span> = 3.5 pc/cm³ turned out to be one of the closest pulsars to the Sun. The absence of new long period transients (pulsars or white dwarf) with periods of tens of seconds with the achieved sensitivity of searching for 1 mJy outside the galactic plane indicates a low probability of the existence of pulsars of neutron stars with extremely long periods. Most likely, the recently found sources of periodic radiation with periods from a minute to tens of minutes are white dwarfs pulsars.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1199 - 1208"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On Massive Black Holes in the Centers of Globular Clusters. I","authors":"S. N. Nuritdinov,&nbsp;S. J. Turaev,&nbsp;K. T. Mirtadjieva","doi":"10.1134/S1063772925701331","DOIUrl":"10.1134/S1063772925701331","url":null,"abstract":"<p>In this paper, a sample of globular clusters (GCs), for which the masses of black holes in their centers are known from observations, has been created. The dependence of the main characteristics of GCs on the mass of black holes has been studied. Based on observational data on the surface density of GCs, the degree of concentration of stars to their center has been determined. The obtained degree of concentration has been used as an indicator of the presence of black holes.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 12","pages":"1385 - 1389"},"PeriodicalIF":1.1,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Problems of Modern Cosmology: The Very Early Universe","authors":"G. S. Bisnovatyi-Kogan","doi":"10.1134/S1063772924701221","DOIUrl":"10.1134/S1063772924701221","url":null,"abstract":"<p>The paper discusses the main problems of modern cosmology, particularly those related to the very early universe.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1 supplement","pages":"S110 - S121"},"PeriodicalIF":1.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496762","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of Massive Stars and Supernovae","authors":"G. S. Bisnovatyi-Kogan","doi":"10.1134/S1063772924701154","DOIUrl":"10.1134/S1063772924701154","url":null,"abstract":"<p>The paper reviews the various stages of stellar evolution and the final stages of this evolution. The nuclear evolution of massive stars, the dynamic stability and critical states of stars of various masses, supernova explosions and their mechanisms, particularly the magneto-rotational model, are considered. The connection between cosmic gamma-ray bursts and supernovae is discussed.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1 supplement","pages":"S56 - S68"},"PeriodicalIF":1.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accretion onto Neutron Stars","authors":"G. S. Bisnovatyi-Kogan","doi":"10.1134/S1063772924701129","DOIUrl":"10.1134/S1063772924701129","url":null,"abstract":"<p>The basic principles of accretion onto a magnetized neutron star are considered: Alfvén surface, instability, hot spot, accretor and propeller, spin-up of stars during disk accretion, stationary period, shielding of magnetic fields, boundary layer, accretion onto a rapidly rotating star with a weak magnetic field.</p>","PeriodicalId":55440,"journal":{"name":"Astronomy Reports","volume":"68 1 supplement","pages":"S31 - S35"},"PeriodicalIF":1.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143496765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}