Swift Launches . ... Credit Copyright: NASA Explanation: Where do gamma ray bursts occur? To help find out, NASA launched the Swift satellite on Saturday, as pictured above . What Swift is designed to do better than any previous satellite is to quickly locate these enigmatic explosions in both sky position and distance. Once a gamma ray burst (GRB) is located, Swift itself will rotate to face it head-on and determine its distance directly. ... NASA Official: Jay Norris. ...

... 2004 November 22 . Swift Launches . Credit: NASA . ... To help find out, NASA launched the Swift satellite on Saturday, as pictured above . ... Once a gamma ray burst (GRB) is located, Swift itself will rotate to face it head-on and determine its distance directly. ... Subsequently collected GRB and afterglow information will help astronomers not only determine the nature of the initial explosions, but also the nature of the expanding shockwaves. ... About APOD | ... NASA Official: Jay Norris. ...

... The exercises are now available on the web and in six booklets (100 pages in total), titled: . ... Exercise 1: Measuring the Distance to Supernova 1987A", . Exercise 2: The Distance to Messier 100 as Determined by Cepheid Variable Stars", . Exercise 3: Measuring the Distance to the Cat's Eye Nebula" and . Exercise 4: Measuring a Globular Star Cluster's Distance and Age". ... More exercises will follow in the future. ... Exercise 3 - Measuring the Distance to the Cat's Eye Nebula . ...

... 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 ...

... Bad Astronomy . ... Mad Science . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... How did early astronomers determine the distance form earth to the sun, and what method is used today to determine distances in space? ... Since Huygens knew the Sun-Venus-Earth angle (from the phases), and he could directly measure the Sun-Earth-Venus angle (simply by measuring Venus' apparent distance from the Sun on the sky) all he needed was to know the distance from Earth to Venus. ...

... Research . ... The major problem in HVC research is the unknown distance towards most of the HVCs. ... Thilker et al. (2004) used the Green Bank Telescope (GBT) to map an area of $7^{\circ} \times 7^{\circ}$ around M31 in H i . They discovered a population of HVCs located within a projected distance of about $50~\mathrm{kpc}$ from M31. ... 2004). ... The remaining HVCs around M31 are isolated in position and velocity and may represent primordial, dark-matter-dominated clouds. ...

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... To avoid extensive numerical calculations in the statistical simulations, we treat the continuous evolution of each binary component as a sequence of a finite number of basic evolutionary states (for example, main sequence, red (super)giant, helium (Wolf-Rayet) star,     hot WD), in which stellar parameters significantly differ from each other. ... Figure 2: Schematic representation of the typical evolutionary track of a massive binary system with normal and compact star stages indicated. ...

. Interplanetary Trajectory Design . "The Longest Journey Starts..." . ------------------------------------------------------ . Previous . Main . Next .

... 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? ...

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Federal Communications Commission (ix)(A) For a station authorized pursuant to § 73.215 or Sec. § 73.509, a showing that the root mean square (RMS) of the measured composite antenna pattern (encompassing both the horizontally and vertically polarized radiation components (in relative field)) is at least 85 percent of the RMS of the authorized composite directional antenna pattern (in relative field). ...

... We want to know time-scales, and sequences of events, and the ages of stars. ... We would, ideally, like to create a solar comparison sample by finding stars of essentially the same mass, composition, and age and then observing the range of behavior they exhibit. ... At best we can estimate a star 's age. ... Having to construct models that work consistently across a broad range of masses constrains the problem, and yet even for the nearest open clusters we do not know the age to even 10%. ...

... April 2, 1999 . Stars of NGC 206 . ... Explanation: Nestled within the dusty arms of the large spiral galaxy Andromeda (M31), the star cluster NGC 206 is one of the largest star forming regions known in our local group of galaxies. The beautiful bright blue stars of NGC 206 betray its youth - but close, systematic studies of variable stars in and around NGC 206 will also accurately reveal its distance. ... About APOD > . ...

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 . ...

... Luminosity (L) · · · · A source's luminosity is the power that it emits in radiation. ... NB Astronomers often say `flux' when they mean `flux density' · SI units are Wm-2Hz -1 -26 filter · Also used are Jy 10 Wm-2Hz -1 E= РРРF d dA dt Specific Intensity, Surface Brightness (I) · Specific intensity (or surface brightness) is the power received (or emitted) per unit area per unit frequency per unit solid angle. ч F at surface of a spherical source = I · · Specific intensity is independent of distance...

Computer Ephemeris. Lunar orbital data. Explanations. ... mean longitude of the Moon (degrees) . ... mean longitude of lunar node (degrees) . inclination of mean lunar equator to real equator of the Earth (degrees) . angular distance from ascending node of mean lunar equator on real equator of the Earth to ascending node of mean lunar equator on ecliptic (degrees) . angular distance from real equinox to ascending node of mean lunar equator on real equator of the Earth (degrees). ...

... The first task assumes the searching for chemical composition and sizes of particles which give the wavelength dependence of the extinction efficiencies close to the observed dependence of . Figure 7: Wavelength dependence of the extinction efficiency factors for homogeneous spherical particles of different sizes consisting of astronomical silicate and amorphous carbon. The dashed segment shows the approximate wavelength dependence of the mean galactic extinction curve at optical wavelengths. ...

... The nebular spectra of SNeIa can be used to determine the mass, density, and distribution of the SN ejecta, and the distance and reddening to the SN. Synthetic spectra can very rapidly be computed in NLTE and compared to the observed ones. Given the relatively large number of parameters, it is convenient to explore the parameter space in an automated form. The nebular spectrum synthesis code can be run in parallel on a workstation cluster. ...