... 2.3 Establishing the Extragalactic Distance Scale . ... 2.3.2 The Second Rung: Distances to stellar clusters . ... 2.3.4 Distances to Local Group Galaxies . ... The Luminosity Function of Planetary Nebulae . ... 3.2.2 Clusters of Galaxies . ... 4.2 Evidence for Dark Matter as a Function of Scale Size . ... 4.3 Other Dark Matter Indicators for Galaxies . ... What is the nature of the large-scale distribution of matter in the universe as traced by the three-dimensional galaxy distribution? ...

... An OBJECT column gives the name of the object observed (usually a star name). ... In critical cases, it is common practice to measure sky on two or more positions around a target object, and these positions must be identified. ... A general treatment of this problem requires a column called OBJECT, bearing the usual name of the object (as in the star tables); a column labelled STARSKY, to distinguish between star+sky, star alone, or sky alone; and additional columns to identify the sky position. ...

Mercury Summer 2011 Table of Contents . ... A Hubble Space Telescope view of a segment of the Coma Cluster of galaxies, one of the densest known galaxy collections in the universe. ... In 1998, competing teams of astronomers were forced to come to grips with increasingly convincing observations that the expansion of the universe was accelerating , rather than decelerating (as they expected). ... Its discovery resulted directly from measurements of the distances to remote galaxies. ...

... GOODS unites extremely deep observations from NASA's Great Observatories, Spitzer , Hubble , and Chandra , ESA's Herschel and XMM-Newton , and from the most powerful ground-based facilities, to survey the distant universe to the faintest flux limits across the electromagnetic spectrum. ... The space-based observations are complemented by ground-based imaging and spectroscopy, including extensive commitments of ESO and NOAO observing time. ... 2010-04-10: Deep VLA 1.4 GHz data for GOODS-North . ...

... This method has no equal as of its versatility and short observation times. ... First observations were made on RATAN-600 with a unique MARS-3 16-channel (32 inputs) Matrix Radiometric System that has no analogue in Russian radio astronomy. ... Centre for Analysis of Multiwave Observations Created on RATAN-600. An on-line processing centre for analysis of multiwave radio observations of the Sun on RATAN-600 was created in the St.Petersburg Branch of SAO RAS, see http://www.spbf.sao.ru/prognoz/ . ...

Next: Rotation Periods of ZAMS stars Previous: T Tauri Stars . ... The first attempts to directly measure periodic modulation of T Tauri stars occurred in the early 1980s. Rydgren & Vrba (1983) observed four PMS stars using photoelectric photometry over a period of seven consecutive photometric nights. ... Because the spot lifetime is much longer than the rotational period, the observed effect will be a modulation of the light from the star synchronously with the rotation period. ...

... P1103 Date Received: 1997-Dec-15 16:59:12 Technical Page Proposal Type: Regular General Category: Pulsars Observation Category: Galactic Total Time Requested: 46 Hours Proposal Title: Pulsar Distance and Galactic Electron Density Determinations via 21 cm Ab- sorption Measurements ABSTRACT: We propose to measure neutral hydrogen absorption spectra of distant pulsars. ... These measurements will be used to calibrate galactic electron density models, which are essential for pulsar population studies. ...

ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . Mopra radio telescope . ... Information & tools for observers . ... Australia Telescope Online Archive (ATOA) . ... ATCA | ... Visiting Parkes radio telescope . ... Parkes radio telescope webcam . ... The Australia Telescope National Facility Colloquium . ...

... Despite new observation methods provided by radar and satellite instrumentation , optical measurements are still important when studying auroras . ... Because of the monochromatic nature of the auroral light, photomultiplier tubes with very narrow band filters were used in the measurements. ... The spectra of the background emissions from atmospheric impurities (clouds, ice crystals, etc.) is rather continuous, and measurements just outside the auroral emission lines are valid for the line itself. ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...

... Flux density at 1 GHz (/Jy): 2720 . ... 1991, ApJ, 373, 146. ... ADS . ... VLA at 1.4 GHz and 4.8 GHz (both 1".3), for polarisation studies. ... VLA at 1.4 GHz and 4.8 GHz, for proper motion studies. ... 151 MHz observations for bulk expansion studies. ... Chandra observations, showing outer shock. ... Fesen et al. ... Spitzer observations. ... Chandra observations of rim. ... 2006, ApJ, 636, 848. ... 2006, ApJ, 647, L41. -ray line observations. ... Spitzer and Chandra observations for 3-D structure...