Astrophysics最新文献

{"title":"Структура магнитного поля звезды HD133880 (si)","authors":"Ю. В. Глаголевский","doi":"10.54503/0002-3051-2023.76.-539","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.-539","url":null,"abstract":"Проведено моделирование магнитного поля звезды HD133880 при предположении структуры магнитного поля описываемого двумя теоретическими магнитными диполями. Сравнение результата с тем, что получалось ранее при использовании представления фазовой зависимости Be() путем дипольно + квадрупольно + октупольного расширения структуры показывает, что эта схема приводит только к формальному описанию фазовой зависимости, а члены разложения не несут физического смысла.The magnetic field of the star HD133880 is modeled under the assumption of\u0000the structure of the magnetic field in the form of a theoretical magnetic dipole.\u0000Comparison of the result with what was obtained earlier when using the representation\u0000of the phase dependence of Be() by dipole+quadrupole +octupole expansion of\u0000the structures shows that this scheme leads only to a formal description of the phase\u0000dependence, and the expansion coefficients do not have physical meaning.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"28 3","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138948192","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":"Периодичность частоты вспышек активных вспыхивающих звезд обнаруженных tess","authors":"А. А. Акопян","doi":"10.54503/0002-3051-2023.76.4-555","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.4-555","url":null,"abstract":"Поступила 8 ноября 2023 По данным орбитальной обсерватории TESS проведено исследование наиболее активных вспыхивающих звезд, показавших по 100 и более вспышек за период с июля 2018 по октябрь 2020гг. Основными направлениями исследования были: а) анализ кривых блеска, определение периодов осевых вращений, выявление физических особенностей у отдельных звезд, б) определение параметров периодической/циклической переменности частоты вспышек вспыхивающих звезд, обусловленной осевыми/орбитальными вращениями. Были получены соответствующие периоды функции частоты вспышек и проведено сравнение с периодами вращения звезд. Периоды функций частоты вспышек оказались близкими к периодам осевых вращений звезд. Построены теоретические распределения вспышек по фазам, которые сравнены с аналогичным наблюдаемым распределением вспышек при данном периоде. Для всех без исключения звезд сравнение с помощью критерия 2 свидетельствует в пользу периодичности частоты вспышек. Предположено, что распределение пятен по долготе вспыхивающих звезд можно представить угловым распределением фон Мизеса, параметры которой определяются через соответствующие параметры функции частоты вспышек. Подробно обсуждена двойственность звезды CD-56 1032.\u0000TESS data was used to study active flare stars, finding 100 or more flares between July 2018 and October 2020. The main objectives of this study were analyzing light curves, determining axial rotation periods, and identifying the physical features of flare stars. The corresponding periodic functions of the flare frequency are derived and checked for possible periodicity matching the star's rotation period. The flare frequency functions correlated closely with the stars' axial rotation periods. Theoretical phase distributions of flares are constructed and compared with a similar observed distribution of flares for a given period. For all stars without exception, this comparison (using the 2 criterion) argues in favour of the periodicity of the flare frequency. It is assumed that the distribution of spots along the longitude of flare stars can be represented using by the von Mises angular distribution, the parameters of which are determined through the corresponding parameters of the flash frequency function. The binarity of the star CD-561032 is discussed in detail.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"35 10","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138952713","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 Digitized First Byurakan Survey DataBase. Late-Type Stars Candidates. New Confirmations. I","authors":"K. Gigoyan, K. Gigoyan, A. Sarkissian, G. Kostandyan, M. Meftah, S. Bekki","doi":"10.54503/0002-3051-2023.76.4-505","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.4-505","url":null,"abstract":"The Digitized First Byurakan Survey (DFBS) is the digitized version of the First Byurakan Survey (FBS, or Markarian survey). The FBS was the first systematic survey of the extragalactic sky. This objective-prism survey was carried out in 1965-1980 by B.E.Markarian and his colleagues using the 1 m Schmidt telescope of the Byurakan Astrophysical Observatory and resulted in discovery of 1517 UVX-excess (Markarian) galaxies. FBS low-resolution spectral plates have been used for a long time to search and study faint Late-Type Stars (LTS, M-type and C stars) at high Galactic latitudes. A total of 18 lists of the FBS LTS were published between 1990 and 2016. We report newly confirmed C and M giants, and also large amount of M dwarfs based on the Gaia DR3 BP/RP low-resolution spectroscopic data base. Some of the newly confirmed M dwarfs presents binary systems. Some of them are new eclipsing binaries. In our previous studies of the DFBS spectral plates, all were presented as LTS candidates. Gaia high-accuracy astrometric and photometric data and Transiting Exoplanet Survey Satellite (TESS) data are used to characterize these new confirmed LTS. TESS phase-dependent light curves show rotational modulations and flares for many new M dwarfs. This confirmations of the large number of completely new objects represents a very significant extension in the census of M giants, faint N-type Asymptotic Giant Branch C stars, CH-type C giants at high Galactic latitudes, and M dwarfs in the solar vicinity. Some objects are located more than 7 kpc from the Galactic plane. Ultimately, we aim to present value-added catalog and update the FBS LTS catalog. Note that a large amount of the blue stellar objects with UVX-excess and numerous of emission line objects were also detected.\u0000Digitized First Byurakan Survey (DFBS) - это оцифрованная версия Первого Бюраканского обзора (FBS) или Маркаряновского обзора. FBS является первым систематическим внегалактическим обзором. Он был осуществлен Б.Е.Мар каряном и его коллегами в 1965-1980гг. с объективной призмой с использованием 1-м телескопа Шмидта Бюраканской астрофизической обсерватории (БАО) и увенчался открытием 1517 галактик с UVX - избытком, названных галактиками Маркаряна. Пластинки с результатами спектральных наблюдений низкого разрешения (lr) обзора FBS длительное время использовались для поиска и изучения слабых звезд поздних спектральных типов (LTS, M и С) звезд на высоких галактических широтах. В период с 1990 по 2016гг. были опубликованы 18 списков объектов LTS FBS. В данной работе сообщается о новых подтвержденных C и M-гигантах, а также о большом количестве M-карликов, подтвержденных данными из архива наблюдений Gaia DR3 BP/RP (спектры низкого разрешения). Часть новых подтвержденных М-карликов представляет собой двойные системы, а часть этих двойных систем является новыми затменными двойными. В наших предыдущих исследованиях спектральных данных DFBS lr они представлены как кандидаты в LTS. Для характеристики новых под","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"113 16","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138958546","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":"Потеря массы атмосферы планеты","authors":"И. С. Саванов","doi":"10.54503/0002-3051-2023.76.4-497","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.4-497","url":null,"abstract":"Представлены результаты анализа проявлений активности звезды WASP-193 спектрального класса F9 с планетой типа супер-нептун. Газовый гигант WASP- 193 b при массе 0.13 массы Юпитера почти в полтора раза больше него по радиусу. Планета имеет низкую плотность   0.059  0.014 г/см3 (аналогичным объектом является Kepler 51 d, число других таких экзопланет мало). Равновесная температура атмосферы планеты высока - Teq = 1254 ╠ 31 К. Полученные результаты изучения активности звезды использованы для оценки потери вещества атмосферы планеты WASP-193 b по аппроксимационной формуле, соответствующей модели потери атмосферы с ограничением по энергии. Оценки величины потока XUVфотонов FXUV были установлены по аналитической зависимости, связывающей FXUV и параметр logRШHK для звезд спектральных классов F - M. Расчеты показали, что потеря вещества атмосферы экзопланеты достаточно велика (даже в случае малой хромосферной активности ее родительской звезды). Диапазон изменений параметра M составляет от 1.8  10 10 г/с до 4.3  10 11 г/с в зависимости от принимаемого уровня потока XUV-фотонов (высокая и низкая активность). Вероятно, что планета интенсивно теряет свою атмосферу. WASP-193 b можно рассматривать в качестве высокоприоритетного кандидата для наблюдений с помощью космических миссий (метрика трансмиссионной спектроскопии TSM для объекта составляет около 600). The results of the analysis of the activity manifestations of the star WASP-193 with spectral class F9 with a super-neptune-type planet are presented. The gas giant WASP-193 b with a mass of 0.13 Jupiter's mass is almost one and a half times Jupiter's radius. The planet has a low density of  0.059  0.014 g/cm3 (a similar object is Kepler 51 d, the number of other exoplanets of this type is small). The equilibrium temperature of the planet's atmosphere is high - Teq = 1254 ± 31 K. The obtained results of investigations of the activity of the star were used to estimate the mass loss from the atmosphere of the planet WASP-193 b using an approximation formula corresponding to the energy-limited model. The flux of XUV photons were established by the analytical relation linking FXUV and logR'HK parameter for stars of spectral classes F - M. Calculations have shown that the mass loss from the exoplanet atmosphere is quite large (even in the case of low chromospheric activity of the star). The range of the parameter M is from 1.8 1010 g/s to 4.31011 g/s, depending on the received level of the flux of XUV photons (high and low activity). It is likely that the planet is intensively losing its atmosphere. WASP-193 b can be considered as a high-priority candidate for observations using JWST space mission (the transmission spectroscopy metric TSM for the object is about 600).","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"10 5","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139169548","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":"Фотометрические и спектральные исследования группы галактических звезд Вольфа-Райе. I. WN последовательность","authors":"Л. Н. Кондратьева, Игорь Витальевич Рева, Э.К. Денисюк, С.А. Шомшекова, Г.К. Айманова","doi":"10.54503/0002-3051-2023.76.4-521","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.4-521","url":null,"abstract":"Фотометрические и спектральные наблюдения 11-ти звезд Вольфа-Райе WN последовательности выполнялись в АФИФ в 2021-2022гг. На основе проведенных наблюдений получены оценки блеска объектов в фильтрах BVRc и абсолютные потоки излучения в эмиссионных линиях. Изменения блеска в пределах 0m.1 - 0m.15 зарегистрированы в звездах WR 1, WR 120, WR 151, WR 152. Изменения эмиссионных потоков обнаружены в спектрах нескольких объектов: WR 120, WR 128, WR 145.\u0000Photometric and spectral observations of 11 W-R stars were carried out at the FAI in 2021-2022. The studied group included representatives of the WN, WC, and WO sequences. Based on the observations estimates of the brightness of objects in the B V Rc filters and absolute fluxes of radiation in the emission lines were obtained. Changes in brightness within 0m.1 - 0m.15 were detected in the stars WR 1, WR 120, WR 151, and WR 152. Changes in the emission fluxes were detected in the spectra of several objects: WR 120, WR 128, and WR 145.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"115 25","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138953807","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":"Viscous Ricci Dark Energy Cosmological Models In Brans-Dicke Theory","authors":"M.Vijayasanthi, T.Chinnappalanaidu, S. S. Madhu","doi":"10.54503/0002-3051-2023.76.4-603","DOIUrl":"https://doi.org/10.54503/0002-3051-2023.76.4-603","url":null,"abstract":"The whole article deals with the analysis of the cosmic model of Ruban's space-time in the context of a bulk viscosity impact in the form of Ricci dark energy within the framework Brans- Dicke theory. We believe that outer space is filled with dark matter and viscous Ricci dark energy (VRDE) under the pressureless situation. The velocity and rate at which the Universe is expanding are presumed to be proportional to the coefficient of total bulk viscosity, is in the form, a / a a / a 0 1 2 , where 0 , 1 and 2 are the constants. To solve the RDE model's field equations, we utilize the relation among the metric potentials and also the power-law relation among the average scale factor a(t) and scalar field . Статья посвящена анализу космической модели пространства времени Рубана в контексте воздействия объемной вязкости в форме темной энергии Риччи в рамках теории Бранса-Дикке. Мы считаем, что внешний космос заполнен темной материей и вязкой темной энергией Риччи (VRDE) в условиях отсутствия давления. Предполагается, что скорость и расширения Вселенной пропорциональны коэффициенту общей объемной вязкости.","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"12 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139302940","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":"Activity of the Young Star EPIC 204376071 from the Upper SCO Association","authors":"I. S. Savanov","doi":"10.1007/s10511-023-09795-x","DOIUrl":"10.1007/s10511-023-09795-x","url":null,"abstract":"<div><div><p>Based on observations from the K2 mission of the Kepler Space Telescope a study is made of the activity of EPIC 204376071, a young object in the Upper SCO association with an age of 11±3 million years whose light curve has a single darkening lasting one day with a depth of about 80%. EPIC 204376071 is a low-mass M-dwarf with a mass of 0.16 M_⨀. Based on observations from the C15 campaign of the K2 mission we refined the rotation period and the amplitude of the variability of the star’s brightness, and also estimated the absolute magnitude of the spottedness parameter A by the standard method. The magnitude of the star’s rotation period, P, equals 1.6270 ± 0.030 days. The area of the spots on the surface of EPIC 204376071 exceeds the maximum spot area on the sun and is on the order of 7900 msh. The results of a recovery of the temperature inhomogeneities on the surface of EPIC 204376071 are presented. Two cold regions separated in longitude by roughly 150° can be distinguished on the constructed chart. For estimating the properties of the flare activity of EPIC 204376071 one of the most reliable flares with a brightness amplitude of about 4% was examined. The measured relative energy RE of the flare was 212 s. The calculated energy E_fl of the flare turned out to be equal to 1.1·1034 erg (logE_fl = 34.05). The probable coronal mass ejection corresponding to it may reach 4.1·10²⁰ g. Published data on the possible nature of the single occultation of diurnal duration with a depth of about 80% on the light curve of EPIC 204376071 are examined.</p></div></div>","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"66 3","pages":"344 - 352"},"PeriodicalIF":0.5,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087374","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 Revisited BPT Diagram from the Self-Consistent Analysis","authors":"P. Privatus,&nbsp;C. Pappalardo,&nbsp;P. V. K. Rao,&nbsp;D. T. Mazengo","doi":"10.1007/s10511-023-09793-z","DOIUrl":"10.1007/s10511-023-09793-z","url":null,"abstract":"<div><div><p>Galaxies' spectral energy distribution has been explored through the use of spectral synthesis codes, and these techniques have been essential in identifying many aspects of the current galaxy evolution model. Most of the spectral synthesis codes that have been developed so far are solely stellar and assume a negligible nebular contribution to the overall continuum. FADO (Fitting Analysis using Differential Evolution Optimisation) is the first spectral synthesis code to fit self-consistently stellar and nebular components. Diagnostic diagrams are powerful tools for classifying galaxies based on the emission line ratio of collisionally excited lines such as [OIII] λ 5007, [NII] λ 6584, [SII] λ 6716, 6731, [OI] λ 6300, and the Balmer recombination lines such as Hα, Hβ. This paper explores the impact of including nebular components on diagnostic diagrams. We investigated the results of the application of FADO to the Sloan Digital Sky Survey Data Release 8 using the data analysed by MPA-JHU, the Max Planck Institute for Astrophysics, and Johns Hopkins University. We found that in all diagnostic diagrams, the fluxes for FADO are higher than those for MPA-JHU; the difference is significant compared to the error in the flux measurement. FADO overestimates the flux ratio of all three diagnostic diagrams over MPA-JHU, but the overestimation is comparable with the line flux ratio errors. The results indicate that the inclusion of a nebular continuum is very important when fitting the spectral energy distribution as it increases the fluxes of all galaxies. However, there is a mild impact from the inclusion of nebular component analysis in the diagnostic diagrams used to classify the ionisation state of galaxies’ interstellar medium.</p></div></div>","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"66 3","pages":"311 - 323"},"PeriodicalIF":0.5,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087387","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":"Modified Tsallis Holographic Dark Energy","authors":"J. Bharali,&nbsp;K. Das","doi":"10.1007/s10511-023-09797-9","DOIUrl":"10.1007/s10511-023-09797-9","url":null,"abstract":"<div><div><p>In this work we propose Modified Tsallis Holographic Dark Energy (MTHDE) in General Relativity (GR) in the framework of Bianchi type III space-time. Einstein's field equations are solved by using a special law of variation of Hubble parameter H proposed by Berman which yields constant deceleration parameter (DP). Interestingly, for the two different constant values of deceleration parameter, we have obtained two different cosmological models. The model 1 behaves like a quintessence dark energy model whereas model 2 behaves like a cosmological constant model. A correspondence between model 1 and quintessence scalar field is established. The quintessence dynamics of the potential and scalar field are reconstructed which illustrates the accelerating phase of the Universe. Various parameters like deceleration parameter, Hubble parameter, anisotropy parameter, equation of state (EOS) parameter, etc. for both the cosmological models are thoroughly discussed. The results obtained are found to be consistent with the recent observations on the present-day Universe.</p></div></div>","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"66 3","pages":"366 - 382"},"PeriodicalIF":0.5,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087378","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":"Motion of a Particle in the Field of an Infinite Flat Slab","authors":"R. M. Avagyan,&nbsp;A. A. Saharian,&nbsp;S. S. Jibilyan","doi":"10.1007/s10511-023-09799-7","DOIUrl":"10.1007/s10511-023-09799-7","url":null,"abstract":"<div><div><p>This paper studies the motion of a light signal and a test particle in the field of an infinite flat slab in terms of the general theory of relativity. The two cases of an external solution for a gravitational field in a vacuum corresponding to Rindler and Taub metrics are examined. The time of the motion and the path traveled by a particle before it stops are determined. It is shown that in the Taub geometry, as opposed to a light signal, a material particle does not reach a singularity. The minimum distance from the singularity is determined as a function of the particle energy. Results in terms of the special theory of relativity are given for comparison.</p></div></div>","PeriodicalId":479,"journal":{"name":"Astrophysics","volume":"66 3","pages":"411 - 422"},"PeriodicalIF":0.5,"publicationDate":"2023-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41087372","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}