... We address a question if globular clusters (GC) in a protogalaxy could for some time evolve chemically as isolated systems, enriching themselves with heavy elements produced in first supernova events that follow initial star formation. We determine both the critical mass of a protoglobular cluster that is needed to retain the ejecta of the very first supernova, and the critical energy (i.e., number of supernovae) that is needed to expel the residual gas from a cluster of a given mass. ...

Status of the RadioAstron project development . The engineering model of the Space Radio Telescope (SRT) was assembled in Lavochkin Association (LA) in the configuration consisting of 10-m parabolic radio astronomical antenna made of carbon-fiber, F ocal and Device cabins of the scientific payload and on-board and ground complex of high data rate up-down radio link (VIRK). ... Then,radio astronomical tests were conducted using real radio sources. ... Space Radio Telescope . ... Data Processing . ...

... Stars . ... Cepheid variable stars have been known since the 18th century. ... Regularly brightening to a peak over days, weeks or months before fading these variable stars were remarkable curiosities to astronomers in past centuries.€а The term Cepheid is taken from the star Delta Cephei in the constellation of Cepheus, which was identified as variable€а in 1784 by the teenaged prodigy John Goodricke (1764-96). ... Tweets that mention Cepheids: Inconstant Stars which break the rules | ...

asncombine -- Process and combine images in one or two NICMOS associations asncombine association . ... set to yes to include error planes in co-added images error. background . ... This is useful to use different background subtractions for different images. fheader . set to yes in order to multiply the background by the value of keyword "factor" in the image header. ... Set to yes to use quadrants statistics save in the image header from previous runs of asncombine. regquad1 . ...

... Over the first 4 years, its X-ray telescopes eROSITA and ART-XC will survey the whole sky with a record sensitivity in the 0.5-10 keV energy band. ... The goal of the second international Spectrum-RG conference is to discuss the different scientific topics addressed by the mission, synergies with surveys at other wavelengths, and requirements to follow-up observations.Contributed talks and poster presentations are invited on the topics related to the SRG science goals. ... Active galactic nuclei . ...

RELATIVE SUNSPOT NUMBERS Description of Data from SGD Explanation of Data Reports: Relative Sunspot Numbers -- The relative sunspot number is an index of the activity of the entire visible disk of the Sun. ... The provisional daily Zurich relative sunspot numbers, Rz, were based upon observations made at Zurich and its two branch stations in Arosa and Locarno and communicated by M. Waldmeier of the Swiss Federal Observatory. ... This indicates the uncertainty above and below the predicted number. ...

... Future seminars . P a s t seminars . Seminar council . Stability of cold fronts in clusters of galaxies " . E. Churazov (IKI, MPA) . ... One of the insteresting results of Chandra and XMM-Newton observatories is the discovery of sharp structures in the X-ray surface brightness of galaxy clusters. These structures (a.k.a. cold fronts) are likely associated with the contacted discontinuities formed when a hot gas flows over a colder gravitationally bound gas cloud. ...

The database contains references to the papers, data files and links to the Internet resources related to measurements and calculations of the optical constants in the wavelength interval from X-rays to radio domain. ... References to some useful books and reviews on the subject (e.g. the classical handbooks edited by E.D.Palik) and links to Internet collections of optical constants and personal WWW pages with related software were also placed in the database. You have arrived at our welcome page. ...

... In order to describe the effect of distortion of the trajectory of an electromagnetic wave in atmosphere, it is needed to use the solution of the dispersion equation of moving medium electrodynamics for the spatial case of atmosphere motion. The solution of the dispersion relation for the propagation of an electromagnetic wave in a medium is valid for an atomic layer with a thickness on the order of a few wavelengths of the electromagnetic radiation. ...

... Bad Astronomy . ... Bitesize Astronomy . ... The next step up are true clusters, called open clusters . Open clusters (sometimes misleadingly called "galactic clusters") are groups of stars ranging in size from a few dozen stars up to tens of thousands. ... The youngest is about 1 or 2 million years old, while the oldest is about 6 or 7 billion years, making it just older than our own solar system. ... So by looking at the stars in the cluster we can tell pretty well how old they are. ...

... Collinder 399 Coathanger Cluster включая Coathanger asterism и рассеянное скопление NGC 6802 (Collinder 400) в созвездии Лисичка (Vulpecula) .. ... Collinder 399 (Cr 399) Coathanger Cluster (Coathanger asterism) . Альтернативное обозначение рассеянного скопления (other IDs) Collinder 399 + астеризм: Al Sufi's Cluster, Brocchi's Cluster, Coathanger Cluster, Coat Hanger Cluster, Coathanger, Coathanger asterism, 4-5 Vulpeculae Cluster, C 1923+200, OCL 113 (Ocl 113.0), Lund 890 .. ... NGC 6802 . ...

... Comments, Opinions Publications Dnepr Program . ... During 1992-2003 timeframe, a team of Russian and Ukrainian companies together with the Russian Ministry of Defense (MoD) were involved in developing a commercial space launch system based on the technology of the SS-18 ICBMs being withdrawn from service. ... ISC Kosmotras was assigned the role of a team leader to build and commercially operate this SS-18 ICBM based space launch system and the entire program was given the name Dnepr . ... Dnepr LV ...

НАУЧНО-ПРОИЗВОДСТВЕННОЕ ОБЪЕДИНЕНИЕ им. С.А. ЛАВОЧКИНА . ... ЭкзоМарс 2016 . ... Социальные проекты . ... Проекты . ... ФГУП 'НПО им. С.А. Лавочкина' - крупное конструкторское и научно-производственное предприятие, проводящее работы по проектированию, изготовлению, испытанию и комплексной отработке ключевых автоматических космических аппаратов для фундаментальных научных исследований. ... Новости Проекты . ... 2016, ФГУП "НПО им. С.А. Лавочкина" - все права защищены ? ...

spaceweb@oulu.fi - last update: 28 May 1995, 0800 UT . Advanced plasma theories are extremely important when one tries to explain, for example, the various waves and instabilities found in the plasma environment. ... In the kinetic theory it is necessary to know only the distribution function for the system of particles. ... The dependence of the distribution function on the independent variables r , v , and t is governed by an equation known as the Boltzmann equation . ... Hot plasma theory . ...