An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . THE CHANGING UNIVERSE: EVOLUTION HAPPENS! . b) Changes in Stars . One of the great discoveries of modern science is that stars (like people) live only a measurable life-time and then die. Although the lives of the stars are enormously longer than the span of a human life, we can learn about the life story of the stars by studying them at many different stages in their life cycle, from birth to death. ...

... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

For Cycle 9 the Science Program Selection Office (SPSO) has changed the selection process to ensure that HST will continue to perform the best possible science with the best return for the astronomical community. This report summarizes the changes to the selection process and offers suggestions on writing an effective proposal that accounts for these changes. ... Fewer panels: With more orbits to allocate, each panel will have more flexibility, especially to approve the somewhat larger proposals. ...

As in the last years, the Ephemerides of Minor Planets for 2015 are prepared by the IAA RAS only in the electronic form. ... Orbital elements of all numbered planets have been determined in IAA all over again on the ground of available observations in the catalog of the Minor Planet Center. ... More detailed information on orbital elements used in the present volume of EMP and their accuracy is given in section "Information on new orbital elements". ... a) information on new orbital elements; . ...

... Bad Astronomy . ... I think I will break from my usual format of Bad Astronomy/ Good Astronomy by saying that the way we define seasons currently is not strictly bad, but I feel (in my opinion!) that it could be better. The definition of when the seasons begin is at the moment of solstice or equinox; that is, winter (in the north) starts on December 22 nd and summer starts on June 22 nd . ... Now imagine breaking up the Sun's 46 degree up-and-down yearly swing into 1 day intervals. ...

Chiaki Kobayashi, Ralph Sutherland How galaxies did form and evolution? - to answer this unsolved problem, we are simulating the formation and evolutionary history of galaxies in the Universe, including star formation, supernovae feedback, and chemical enrichment. Comparing the spacial distribution of elements within galaxies with observations, we will examine fundamental physical processes that drive galaxy formation. ... COALA : Universe Galaxy AGN Star Planet ...

... Tonight's Sky . ... The Magazine . ... Star Atlas . ... An artificial comet holds secrets to Earths life . ... Astronomy for Kids . ... Observing springtime deep-sky objects with a large telescope . ... The planet has extreme temperature swings and perhaps active lava flows. ... A digital supplement to Astronomy magazine. ... Join TravelQuest International with Astronomy and Discover magazines on one of three great tour options surrounding this celestial spectacle . ... Astronomy Magazine . ...

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. ...

... Stellar cinders . Born-again stars . ... Heavyweight Stars . ... What will happen inside the Sun and why? ... These are questions about "stellar evolution", the history of stars as they are transformed by nuclear processes deep inside. ... Most of what we know about stellar evolution comes from computer models of stars. ... We learn about the evolution of high-mass stars from HR diagrams of young galactic open clusters, and the evolution of low-mass metal-poor stars from old globular clusters. ...

... General information . ... Staff . Research staff . ... Information . ... Historical highlights . Historical research . ... This process is thought to occur in circumstellar disks of gas and dust around young stars on rather short timescales : infrared surveys show that the number of low mass stars with disks drops dramatically for stars older than 10 Myr, suggesting that in order to form large solids before the disk disperses, the growth process has to take place within a few million years. ...

... Subject of Astronomy. ... Basis of Spherical and Practical Astronomy. ... Celestial Sphere. ... Changes of Star's Coordinates as a Result of Daily Rotation of Celestial Sphere. ... Time Measuring. ... Changes of Solar Equatorial Coordinates. ... Stellar Day, Stellar Time. ... Real Solar Time. ... Mean Solar Time. ... Connections between Stellar and Mean Time. ... Apparent Path and Configuration of Planets. ... Ways of Energy Transportation to Stellar Surface.Basis of Spectral Analysis. ... Solar...

... Since planets are expected to form out of the material in disks around young stars, the formation of a planet will thoroughly alter the structure of the circumstellar disk of their host star, forming significant gaps in the radial distribution of matter around the star. Additionally, processing of solids (annealing/crystallization) and changes in the overall gas/dust ratio are thought to happen during the planet formation process and are believed to alter the observational signature of the disk. ...

Teaching courses . for student of the Department of Astrophysics and Stellar Astronomy . ... Geophysics and physics of the planets (Kurt, Panteleev) . ... Close Binary Stars . ... Solar Physics . ... This is introductory course for students of the third year of education which are familiar with elementary astronomy and general physics. ... The one-year course includes theory of radiation transfer, theory of internal stellar structure with account of binary systems with compact comapnions. ...

... Archives . ... X-ray summer school is on going. ... Recently I went to JSM 2007 and tried to attend talks about (bayesian) change point problems, which frequently appears in time series models, often found in economics. ... Tags: ARCH , Bayesian Block , challenges , change point problem , GARCH , light curves , summer school , X-ray . ... I received another type of changing point problem, defining a peak precisely, from a x-ray school student, who tried bayesian block but said it didn?t work. ...

... Any water on Mars is locked up in the ice caps. ... The most recent successful mission to Mars is the Mars Science Laboratory better known as the Curiosity rover. ... CuriosityтАЩs primary role is to search for conditions that may have once been able to harbour any sort of bacterial life concealed beneath the Martian surface. ... Using what we know about life on Earth, where there is water, there is life, signs of water may help us understand what Mars was like billions of years ago. €а . ...

... Up: Data Analysis and Processing Techniques . ... Also, a method for quality control of CCD observations is suggested. ... Everyone who observes a celestial object using a CCD detects moving celestial objects as a ``by product''. ... We hope that our investigations may be useful for near-Earth space control and also for searches of the moving celestial objects through analysis of old and new CCD frames obtained at any amateur or professional astronomical observatory. ...

The Face on Mars . ... The Raw Images . Table 1: List of Viking Orbiter Images of the "Face on Mars" . ... Processing the Face Images . Table 2: Dimensions of Mercator Projected Images of "The Face on Mars" . Map Projected Images . ... Processing the "Face on Mars" Images . ... This page will provide interested persons with both the raw Viking images, transformed to GIF format, and a brief tutorial (with examples) of image processing techniques applied to create "better looking" images. ...

... SciSim release covered by this note . ... Data-Analysis-with-SAS in a simple and standardised way, and should allow calibration experts to re-assess the reliability of the different elements of XMM-Newton simulations. ... Also, a release of all calibration files to be used in the reduction, through the SAS, of SciSim generated data, is coordinated with this release. ... Furthermore, two SAS tasks (odffix and epicproc) had to be updated to make possible a proper SAS data reduction of simulated data. ...

Peremennye Zvezdy ( Variable Stars ) 26 , No. ... Moscow 119992, Russia . ... 84/32, Moscow 117997, Russia . ... Our CCD observations compared to times of minima derived from the archival photographic plates and from the NSVS and ASAS-3 data clearly show that the orbital period of the system is variable. ... The phased light curve for the light elements . ... CCD, Moscow . ... and for the current linear light elements (in excellent agreement with the NSVS, ASAS, and our CCD observations): . ...

Pulkovo NEO Page . ... EPOS Software Package . ... EPOS ( E phemeris P rogram for O bjects of the S olar system) is the Windows PC application for study and ephemeris support of observations of the Solar system objects. ... It controls the part of common data and transfers the control to one of the programs that solve the restricted set of tasks. ... So with the EPOS software package one can calculate the accurate ephemerides for many objects and get the quick illustration of their motion as well. ...