Fundamental parameters and time evolution of mass loss are investigated for post-main-sequence stars in the Galactic globular cluster 47 Tucanae (NGC 104). ... We confirm the cluster's distance as d = 4611+213 -200 pc and age as 12 ТБ 1 Gyr. Horizontal branch models appear to confirm that no more red giant branch mass loss occurs in 47 Tuc than in the more metal-poor Я? Centauri, though difficulties arise due to inconsistencies between the models. ...

... Credit Copyright: Nicolюs Villegas Explanation: Large galaxies and faint nebulae highlight this deep image of the M81 Group of galaxies. ... Around the image many other galaxies from the M81 Group of galaxies can be seen, as well as a lucky satellite glint streaking across the image left. ... This whole galaxy menagerie is seen through the faint glow of an Integrated Flux Nebula , a little studied complex of diffuse gas and dust clouds in our Milky Way Galaxy . ... Galaxy Wars: M81 versus M82 . ...

An ephemeris can be calculated with different accuracy. Calculation accuracy dialog presents three modes of accuracy. One can calculate position of a minor planet by the formulae of elliptic motion starting from the fundamental set of elements for given minor planet. ... Also there is possibility to calculate positions taking into account perturbations from different sets of perturbing bodies by numerical integration ( Integration mode). ... Accuracy of integration is equal to 10**(-10) AU. ...

The seminar is supported by the grant of Federal Programm "Integration" . ... A.V.Ivanchik, A.Yu.Potekhin, D.A.Varshalovich "Testing of possible cosmological variation of fundamental physical constants by analyses of QSO spectra" . ... Based on high-resolution measurements of quasar spectra, we obtain the following direct limits on the average rate of the cosmological time variation of the fine-structure constant alpha : . alpha'/alpha| -14 yr -1 . It is the most conservative limit. ...

Next: Imaging by an Optimizing Method . ... A big advantage of this numerical integrator is its stability: the error in the semi-major axis and the eccentricity depends only on the step size and does not grow with an increasing number of time steps. ... As the integration time increases, the numerical results become more contaminated by various errors. ... A new symplectic integrator produces no secular truncation errors in the actions of a Hamiltonian system. ...

... Tonight's Sky . ... Observing . ... Sky this Month . ... Gravitational wave search provides insights into galaxy evolution and mergers . ... The double star 54 Leonis, spiral galaxy NGC 3198, and emission nebula NGC 3199 . ... Observing Podcasts . ... Astronomy for Kids . ... Galaxies and the integrated flux nebula in Ursa Major . ... Get instant access to subscriber content on Astronomy.com! ... Receive news, sky-event information, observing tips, and more from Astronomy's weekly email newsletter. ...

Next: Introduction . ... A spike immunity method of digital integrating radiometer signals in the jamming environment is described. ... The purpose of the method is real-time signal processing, and the basic is an alternative selection of the least offset signal estimation using nonparametric "Nearest Neighbor" rule. ... The additive spike-like jam makes the "tails" of the distribution "heavier" which leads to different offsets for linear and rank mean estimation on the integrating interval. ...

... Science Users Information > Observing Facilities > Instrumentation Development > Integration Cryo-Vacuum . ... Integration Cryo-Vacuum . ... MAD . ... Semented Mirror . ... Paranal Instruments . ... ESO Departments . ... July 2010 . ... October 2008 . ... Jan 2008 . ... Our department has been involved for many years in the first generation VLT instruments. ... MAD first MCAO ever . ... This visitor instrument was fully integrated uder the responsibility of the integration and cryo-vacuum department...

... 4 A I. I NTRODUCTION AND BACKG ROUND A Superconducting Integrated Receiver (SIR) [1] comprises on one chip a low-noise SIS mixer with quasioptical antenna, an Flux-Flow Oscillator (FFO) acting as a Local Oscillator (LO) and a second SIS harmonic mixer (HM) for the FFO phase locking (see Fig. ... In the SIR the bandwidth is determined by the SIS mixer tuning structure and the matching circuitry between the SIS and the FFO. ...