... 4. (a) Distribution of distance from the Galactic plane, (b) kinematic diagram, and (c) relation between metallicity and distance from the Galactic plane for RR Lyrae stars with [Fe /H ] > -0.95 . ... The solid line in the middle panel is a regression line, whose slope is determined by the subsystem’s rotation rate; the open circles and dashed line correspond to stars with [Fe/H] > -0.4, and the filled circles and dashed line to stars with -0.95 < [Fe/H] < -0.4. ... next figure | privious figure . ...

. Next: Optical identifications Up: Distances Previous: Timing parallax . љ . Distance determined for > 50 pulsars . Main method of calibrating DM distances . Requires a model of the Galactic rotation . Compare structure in absorption and emission . Gating on the pulsar helps to extract the weak absorption signal . љ љ . Figure 15: Hydrogen 21cm line spectra. From Lyne & Graham-Smith 1990 [ 23 ] . Jon Bell . Thu Dec 19 15:15:11 GMT 1996

We present an extinction analysis of sight lines selected from all public FUSE observations of Galactic O and B stars. Over 90% of Milky Way extinction curves sampled from IR through UV wavelengths (UV coverage provided by IUE) conform to the CCM family of curves based on R(V), a single parameter linked to grain size (Cardelli, Clayton, Mathis 1989, ApJ, 345, 245; Valencic, Clayton, Gordon 2004, ApJ, 616, 912). ... ADS ] . ADS Citation Query . ...

... SQL | ... Tutorial: determine H0 using SQL queries to LEDA . ... We select in the database all galaxies with known velocity and magnitude and similar to a given template for which we know the distance, the magnitude and the radial velocity. ... We simply have to choose a property which does not depend on the distance, as for example the rotation velocity ( log(vrot) ) and select the galaxies having log(vrot) in a very narrow range around the value for the template galaxy. ... leda@univ-lyon1.fr ...

The ESA/ESO Astronomy Exercise Series 2 . The Distance to Messier 100 as Determined by Cepheid Variable Stars . ... The small variations in distance to the individual Cepheid variable stars in the Cloud are negligible compared with the much larger distance to the SMC. ... In this way Cepheid variable stars can be used as one of the 'standard candles' in the Universe that act either as distance indicators themselves or can be used to calibrate (or set the zero point for) other distance indicators. ...

True Color Image Gallery: Galactic SNR | Magellanic Cloud SNR . ... Radio Images Page . ... Exposure uf . ... Exposure uf Exposure time of unfiltered event file . Exposure f Exposure time of filtered event file . ... Event 2 FITS File . ... AUX file . ... Region . ... see fit detail page for more about the fit. see chandra spectrum page for region used. Images in Several Energy Bands . ... Spectra of Several Regions . ... 1.0" . ... in central region . ... in central region, double? ...

... This document and the attached postscript figure document an analysis that I did to determine the optimum midpoint and required ranges for both the rotator and azimuth for the 2.5 M telescope. ... I simulate a series of drift scans on the sky for tracks that cover the northern survey area. These tracks cover the range in survey latitude of -60 to +60 degrees, spaced by 10 degrees. ... Along each track the azimuth, elevation, and position angle of the CCD is computed at 1 minute intervals. ...

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The azimuth encoder rack gear is mounted on the inside of the azimuth ring girder. The azimuth encoder turns on this gear as the azimuth moves 0 to 720 degrees. ... The software assumes that this arc length along the encoder rack gear is correct (at a constant radius of 127/2 feet). The error in the radius of the rack gear becomes an azimuth error. To measure the error in the azimuth encoder rack gear, jon hagen built a proximity sensor. ... To compute the az encoder runout error: . ...

... Keywords: Proper Motions, Schmidt Plates, Astrometry, Guide Star Catalog, Palomar Sky Survey . In this paper we describe a program of determining proper motions from digitized scans of 1950's-era Palomar Sky Survey (POSS) Schmidt Plates and 1980's-era Palomar Oschin Schmidt `Quick V' plates that were taken for the Hubble Space Telescope ( HST ) Guide Star Catalogue. ... Arrows indicate the magnitude and direction of the proper motion for the stars. ...

... Armagh Observatory, College Hill, Armagh BT61 9DG, +44 (0)28 3752 2928 . ... The light curves of our blue candidate stellar pulsators identified in our survey and which had an amplitude less than 0.2 mag. ... Assuming they are pulsating in either the fundamental or first over-tone radial mode the ma- jority are located at a distance greater than 3kpc, with several being more than 20 kpc distant. Most stars are at least 1 kpc from the Galactic plane, with three being more than 10 kpc. ...

Next: The Scenario Machine: Operational Up: Evolution of Magnetic Rotators Previous: Ejector-propeller hysteresis . ... The length of this segment is determined by the eccentricity. ... In this case no hysteresis occurs and transitions E -- P and the reverse take place in symmetrical points of the orbit. ... Here EP means a mixed state of the rotator at which it is in the ejector state during one part of the orbit, and in the propeller state during the rest of the orbital cycle. ...

Aristarch is Copernic of Classic World. ... First Aristarch determined the fact for how many times the Sun was father then the Moon and then he compared the Sun and the Moon with the Earth. ... Only the Moon rotates around the Earth. ... Gipparch suggested that the Sun turned around the Earth steady and in circumference but the Earth is displaced according its centre. ... The orbit point in which the Sun is nearer to the Earth Gipparch called perigee and the most remote one he called apogee . ...

... CEPHEID VARIABLE STARS: A Cepheid variable or Cepheid is a member of a particular class of very luminous, massive variable stars with pulsation periods of 1-70 days. ... The relationship is calibrated using data collected from Cepheids whose distances are determined by other means. ... Browse through the 68 CCD fits images he sent you, using ds9 and locate the Cepheid variable. ... Image credits: ESA - "http://sci.esa.int/science-e-media/img/20/cepheid-variables.jpg" . ...

... For more distant stars we must use other techniques. ... Hence if we see a distant galaxy and can pick out any cepheids lying within it, we can calculate its distance. ... Here then is another method to gauge the size of the Universe and there are yet more. volume at high enough temperature a nuclear fusion reaction sweeps across the white dwarf's surface and eventually we will see a spectacularly bright new star (hence nova) in our skies. ... Why is this relevant to the size of the Universe? ...

Stellar population of the interacting galaxies M51. ... Stellar photometry of about one million stars in the system of the interacting galaxies M51 has been carried out on the basis of the ACS images of the Hubble Space telescope. ... A comparison of the stellar distribution in the main galaxy NGC 5194 with the empirical model of the distribution of stars showed their similarity, in spite of interaction in the system. ...

J/AstL/vol/page SAI Open Clusters Catalog (Glushkova+, 2009) ================================================================================ Automated search for star clusters in large multiband surveys. ... Color excesses E(B-V), distance moduli and ages were determined for 141 new and 27 known, but poorly studied clusters. We present the Sternberg Astronomical Institute Open Clusters Catalog (SAI OCL Catalog) of coordinates, diameters and main physical parameters of these clusters. ...

... U. Amsterdam Explanation: The GRB distance scale controversy may have just ended with a flash . Gamma Ray Bursts (GRBs) are powerful explosions occurring in seemingly random positions on the sky. ... There they found a faint but variable optical source : a potential counterpart to the gamma-ray burst that was getting brighter. Most importantly, continued scrutiny showed that this optical transient had absorption lines with a redshift of about 0.8 - the distance scale of galaxies and quasars . ...

Next: NICMOS/HST H-band (F160W) Images Up: NICMOS Science Previous: HST NICMOS Observations of . ... Observations of P . ... The NICMOS team has devised a comprehensive program of observations of the Galactic Center. ... Data in hand give a first look at variability and a detailed look at the search for the tip of the main sequence will be discussed where NICMOS has demonstrated adequate sensitivity and photometric precision to identify likely O8-B1 stars at the Galactic Center. ...

Institute of Applied Astronomy Russian Academy of Sciences Method of Determining the Orbits of the Small Bodies in the Solar System Based on an Exhaustive Search of Orbital Planes Dmitrii Vavilov, Yurii Medvedev Introduction to the problem: Let we have n 3 positional observations of a body: points in time ( = 1, ) , right ascensions , and declinations . ... Determination of the orbit using the Gauss method of determining orbital elements based on two heliocentric positions and points in time. ...