... For SIMS (Secondary Ion Mass Spectrometry) analysis, a solid surface is bombarded by primary ions of some keV energy. ... The subsequent mass analysis of the emitted ions provides detailed information on the elemental and molecular composition of the surface. ... Extremely short ion pulses with a duration below . ... By rastering a fine-focussed ion beam over the surface, like an electron beam in an electron microprobe, mass resolved secondary ion images (chemical maps) can be obtained...

... Астронет | ... Переменные Звезды | ... Микролинзирование . ... На протяжении последних нескольких лет в рамках проекта MACHO проводятся наблюдения микролинзирования звезд Большого Магелланова Облака - спутника нашей Галактики. Эффект микролинзирования заключается в гравитационной фокусировке света звезды массивным объектом, находящимся на луче зрения между звездой и наблюдателем. ... Согласно некоторым гипотезам, линзами могут являться реликтовые черные дыры или "нейтралинные звезды". ...

... About ATNF overview . ... Both are consistent with earlier estimates, computed for the population of optically selected galaxies. This consistency occurs because, although the distribution of optical central surface brightnesses among galaxies is flat, we fail to find a population of galaxies with central surface brightnesses fainter than 24б  B - , even though there is no observational selection against them. Keywords: Galaxies: Luminosity Function, Mass Function; Surveys . ...

Next: MASSES Up: EXTREME HELIUM STARS: PULSATION Previous: STELLAR PROPERTIES . ... Following main-sequence evolution, a red giant star in a close binary system may expand to fill its Roche lobe. ... Although Iben & Tutukov (1984) used this model to account for the EHes, the latter are not binaries (Jeffery et al. ... Final helium-shell flash in a post-AGB star. ... Accretion from the disk onto the surviving WD creates a star with a degenerate CO core and a helium envelope. ... Other models. ...

Next: Other parameters of the Up: The Model Previous: Initial binary parameters . As we only deal with initially massive binary systems (their primary's mass is higher than 10 ), which are capable of evolving off the main sequence during less than years, the compact stars left behind stellar evolution are (in the case of the most massive stars) NSs and BHs. ... For a NS belonging to a binary, the evolution complicates as the secondary star evolves: for example, (recycling), etc. ...

... This appartus will drop a mass from different heights. When the mass strikes the ground, some percentage of its original energy will be absorbed by the ground. ... The percentage of the energy which is absorbed by the surface on each "bounce" (EAS) . ... The impact velocity of the object will also be given at each bounce. ... Start= Drop the ball after Energy, Mass and EAS have been set; resume after step or pause has been selected . ... Reset = Reset experiment to intial values . ...

Pulsars can be used to study the strong nuclear force. The density of matter at the center of neutron stars is one or two orders of magnitude larger than the density of atomic nuclei. ... Very "soft" EOSs predict lower pressures for a given density, i.e., highly compressible matter. ... If more precise measurements can confirm this high value, then many model EOSs for dense matter can be ruled out. ... Another way of studying the behavior of super-dense matter is to find fast pulsars. ...

... Resembling a gigantic hubcap in space, a 3,700 light-year-diameter dust disk encircles a 300 million solar-mass black hole in the center of the elliptical galaxy NGC 7052. ... Because the front end of the disk eclipses more stars than the back, it appears darker. ... Despite its size, the disk is 100 times less massive than the black hole. ... The bright spot in the center of the disk is the combined light of stars that have crowded around the black hole due to its strong gravitational pull. ...

... Figure 2 : NGC 7052 HST images . ... MPG Movie : Animation of stellar motions around black hole in M32 . Massive BHs are thought to be responsible for the energy production in active galaxies, and are believed to be common in quiescent galaxies as well. Dynamical evidence for this can be sought by studying the kinematics of stars and gas in galactic nuclei. In the 1970's M87 was the first galaxy for which stellar kinematical data hinted at a BH, but not conclusively. ...

Compact laser time-of-fligh mass-reflector (LASMA) . ... Earlier developed distant laser mass spectrometer LIMA-D was used in the Soviet project Phobos. For the new Phobos-Grunt mission two instruments are developed: MANAGA-F for the secondary ion detection and LASMA for the detection of elemental and isotopic composition of the Phobos regolith. ... Mass resolution                                                     300–500 . ... in 1000 shots (t < 1 min)                           ~300 ppbA ; . ...

... Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2016 January 10 . Sun Storm: A Coronal Mass Ejection . Image Credit: NASA , ESA , SOHO Consortium . ... Another Coronal Mass Ejection (CME)! ... Direct light from the sun is blocked in the inner part of the featured image , taken in 2002, and replaced by a simultaneous image of the Sun in ultraviolet light . ... About APOD | ...

Blackholes2 Forum Message . ... Holostars: Black Holes Without Event Horizons . ... Its name derives from the fact tht information is preserved in such a black hole, and must be a contraction of hologram and star. ... The exterior metrics and fields of the charged holostar are equal to the Reissner-Nordstroem black hole solution. ... www.astronomy.net . ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... Development of Ideas of Structure and Evolution of Stars. Integral Features of Stars, Which Determine Their Structure, Direction and Rate of Evolutuion. ... Connection between Potential and Thermal Energy of Star. ... Structure of a Main Sequence Star. Features of Massive Stars Evolution on the Main Sequence. Internal Structure of the Sun. ... White Dwarfs, Their Features. ... Evolution from the Main Sequence of Massive Stars. ... Evolution of Small Mass Stars till White Dwarfs Sequence. ...

DARK MATTER IN THE UNIVERSE Paul J. Green UNSEEN MASS: Astronomers studying the motions of stars and galaxies throughout the universe have long noticed a strange discrepancy. Stars move around galaxies as if pulled by ten times the matter that we can see. ... GRAVITATIONAL LENSING: Since dark matter by definition cannot be directly observed, several recent searches have instead exploited the predicted gravitational effects of its mass on the observed light from nearby stars. ...

The Sun is our nearest star and the source of energy for life on Earth. ... For centuries astronomers wondered whether they were clouds floating in the Sun's atmosphere, but we now know that they really are huge regions of magnetic field, about as intense as the field at the poles of an iron magnet. ... Such abrupt events were named solar flares , and what made them especially interesting was that occasionally, after a prominent flare, a magnetic storm would erupt on Earth. ...

Mercury - is the nearest to the Sun. Ellusive planet. ... They had several names for this star: Set and Gor (ant. ... The same surface spot with many craters, some of which has the systems of light beams only dark spots, like the Moon seas were considerably less. ... Further was the period of intensive bombing Mercury by the remains of before planet’s swarm (planetozimalies), when the ponds were founded for example Colories (diameter - 1300km) as well as craters like Copernic crater in the Moon. ...

... Ever wonder how solar-mass stars form?. ... In order for material to accrete onto a protostar it has to lose angular momentum. The angular momentum of a large natal cloud leads to the formation of a circumstellar disk and inner accretion disk as the cloud collapses. ... Winds generated in the inner disk or close to the stellar surface (we don't know which) expel material along the disk rotation axis. ... This provides the highest resolution observational data on nearby young stars. ...

... The Galactic low-mass X-ray binary GS 2023+338 was discovered during the burst on May 22, 1989 with the Japanise satellite Ginga (aka Galaxy). The flux reached 17 crabs (this unit of flux measurement is an bright X-ray source, Crab Nebula) at 10-35 keV. ... No other radio telescope worldwide carried out multi-frequency measurements. ... Upon 14 days the radio flux fell below the detection level at the RATAN-600 in relation to the decrease of the X-ray flux. ...

Class 1 Introduction, Background History of Modern Astronomy The Night Sky, Eclipses and the Seasons Kepler's Laws Newtonian Gravity General Relativity Matter and Light Telescopes Class 2 Solar System Characteristics Formation Exosolar Planets Class 3 Stars The S un Stellar Evolution of Low and High Mass Stars Deaths of Stars Exotic Stars Class 4 Galaxies Galaxy Classification Formation of Galaxies Galactic ... Low mass stars live and die differently than high mass stars. ...

The Mass-Density of the Universe and the Distribution of Dark Matter Neta A. Bahcall Princeton University, USA One of the most fundamental questions of cosmology is: How much matter is there in the Universe and how is it distributed? Here we show that several independent measures - including those utilizing clusters of galaxies - all indicate that the mass-density of the Universe is low: only 20-30% of the critical density. ... The results reveal a low den- sity of 0.16+-0.05. ...