All stars derive their energy through the thermonuclear fusion of light elements in to heavy elements. High temperatures are required so that the mutual electrostatic repulsion of the protons in each fusing atomic nucleus is overcome. ... Elements with more protons in their nuclei require higher temperatures. ... This sequence is now shown in the animation below. ... First Step of the Proton-Proton Chain Narration . Second Step of the Proton-Proton Chain Narration . ...

. Accurate flux calibration is required to derive to many intrinsic properties of the galaxy like star formation rate. It is also required to compare the data from different instruments. In this FoF I will summarise some of the issues (and hopefully their solutions) encountered while flux calibrating data from DEIMOS spectrograph on KECK.

. 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

... Hyunsook recently said that she wished that there were ?some astronomical data depositories where no data reduction is required but one can apply various statistical analyses to the data in the depository to learn and compare statistical methods? ... Tags: ADC , astro catalogs , Cast , CDF-S , Chandra , datasets , HEASARC , Penn State , reduced , standard processing , W3Browse . ... Tags: astrostatistics , Babu , Cast , Feigelson , Penn State , R , statistics department , summer school . ... Comment...

Using the free source form it is not permitted to have comments starting with a C or a * in column 1. This would be a violation of the free format. ... An advantage compared with earlier Fortran standards is that the standard now requires that the compiler can signal if the user deviates from the permitted standard. It is required that a Fortran 90 compiler can signal . ... It has to be possible to ask the program to signal for any extensions outside the Fortran 90 standard. ...

A press release on the Canadian Galactic Plane Survey was associated with this poster. ... Below are maps of HI emission, HISA, and 12 CO emission in the eastern 25% of the survey, given as projections along the velocity ( Figure 1 ) and latitude ( Figure 2 ) axes. ... 2000, A. J. , submitted . ... GIF | ... We are developing automated methods of locating HISA in velocity cubes by removing large-scale emission in space and velocity and flagging small-scale dark residuals. ...

... Abstract Given a relational operator, compare two sets of any data type. Required_Reading CELLS, SETS . ... The function returns the result of the comparison: a (op) b. Detailed_ Input a is a CSPICE set . a must be declared as a character, double precision, or integer SpiceCell. op is a comparison operator , indicating the way in which the input sets are to be compared. op may be any of the following: Operator Meaning -------- ------------------------------------- = a = b is ...

... Observatory data . ... Required stellar data . ... Comment column . ... UT date --- column label: DATE . MJD --- column label: MJD_OBS . ... Column label: TELESCOP . Column label: DIAM . Column label: LON . Column label: LAT . Column label: HEIGHT . ... Descriptor for the ``horizon'' table . ... Instrument configuration and run-specific information . Storage format . ... Column DET . ... Sample instrument files . ... CCD photometry . ... Required observational data . ...

... Star Atlas . ... stars . ... Nuclear fusion of hydrogen into helium powers stars, but fusion requires a lot of energy. Where does this energy come from? ... You re in good company: This question also stumped the physicists who first tried to understand nuclear fusion in stars. In a star s core, all atomic nuclei have been separated from their electrons, so each hydrogen atom is really just a proton and thus holds a positive charge. ... Get instant access to subscriber content on Astronomy.com! ...

... QSO spectra in the ROSAT band are steeper than the background at harder energies, and furthermore at fluxes below 1E-14 ergs/(s cmќ) the quasar source counts flatten off and are replaced by more numerous populations of relatively low red-shift objects, apparently Narrow Emission Line Galaxies (NELG). ... We extracted the luminosity function from ROSAT Deep Survey results, and extrapolated by a factor of 2 - 3 to account for changes expected in the harder XMM band. ...

... We give evidence that lower pressure model chromospheres can alos reproduce the Balmer line profiles, but give Lyman surface fluxes overestimated by more than an order of magnitude. ... We obtain the Paschen lines in emission and Paschen decrements as large as 41 for Pa$_{\beta}$. ... Formation of all Hydrogen series is collisionally controlled and takes place in a rather thin layer at the top of the chromosphere (Balmer, Paschen, and Brackett) or in the transition region (Lyman). ...

... Apache HTTP Server Version 2.2 . ... Authorization based on file ownership . ... This module authorizes access to files by comparing the userid used for HTTP authentication (the web userid) with the file-system owner or group of the requested file. ... file-owner . ... The name of the system group that owns the file must be present in a group database, which is provided, for example, by mod_authz_groupfile or mod_authz_dbm , and the web-username must be a member of that group. ... Require file-group...

... Table of Contents . Author Index . Subject Index . Enter words for search: . This is a WAIS search of the entire contents of all the articles, performed by the wwwwais gateway program. ... You may use "and" and "or" in a search. For example, compare the results of a search for "midas and aips" to the results of searching for "midas" alone. Copyright 1997 Astronomical Society of the Pacific , 390 Ashton Avenue, San Francisco, California 94112, USA . ...

... The hotter the gas, the faster they move, and the more energy each of them holds. The free ions and electrons in a plasma behave the same way. Knowing the temperature of the high atmosphere of Earth, or that of the Sun, we can calculate energies expected of ions and electrons found there. However, ions and electrons actually observed in space are often much , much more energetic, and may move at a respectable fraction of the velocity of light (300,000 km/sec or 186,000 miles/sec). ...

... The <B> element specifies that the enclosed text should be displayed in a boldface. ... The <I> element specifies that the enclosed text should be displayed, if practical, in an italic font (or slanted). ... The <SMALL> element specifies that the enclosed text should be displayed, if practical, using a small font (compared with normal text). ... The <SUB> element specifies that the enclosed text should be displayed as a subscript, and if practical, using a smaller font (compared with normal text). ...

... Astronomy . ... Requires various plug-ins to your browser to work right. [m,h] (A simpler version of this activity, to be done with printed paper versions of the image, can be found at: www.jpl.nasa.gov/galileo/sepo/educaton/europa/puzzle.html ) . ... Interesting activity, in which students use an inexpensive "stream tray" to simulate the flow of water on sandy terrain, compare their results to features seen in martian images, and then try to replicate some of the features seen on Mars. ...

... The sample of the Local Volume galaxies (distance smaller than 10 Mpc) gives a unique opportunity to study the properties of galaxies including the weakest objects: the absolute magnitude M B -10 and the virial mass M vir 10 9 M x263C;. ... Luminosity function of the Local Volume galaxies. ... The luminosity functions for galaxies are presented: red dashed line - from the 2dFGRS survey (Norberg et al. 2002); blue dash-dotted line - from the SDSS survey (Blanton et al. ...

... Energy . ... The free ions and electrons in a plasma behave the same way. Knowing the temperature of the high atmosphere of Earth, or that of the Sun, we can calculate energies expected of ions and electrons found there. However, ions and electrons actually observed in space are often much, much more energetic, and may move at a respectable fraction of the velocity of light (300,000 km/sec or 186,000 miles/sec). ... Typical energy of an electron in the polar aurora. 40,000 ev . ... 50,000 ev . ...

... Corporation . OAO RSC Energia . President of the Corporation . ... Brief History of Rocket and Space Technology . ... Space Station MIR . ... Space Records . ... Image . ... Contribution of RSC Energia to the Russian Space Technology . International Space Station . Project History . ... First Crew . Required Resources . ... Images . ... Second Crew . ... First Russian Visiting Crew . ... Third Crew . ... Fourth Crew . ... Rockets . ... Official WEB-site of S.P.Korolev RSC Energia . ...

trend1d - Fit a [weighted] [robust] polynomial [or Fourier] model for y = f(x) to xy[w] data. trend1d -F < xymrw > -N [ f ] n _ model [ r ] [ xy [ w ] file ] [ -C condition _# ] [ -H [ nrec ] ] [ -I [ confidence _ level ] ] [ -V ] [ -W ] [ -: ] [ -bi [ s ][ n ] ] [ -bo [ s ] ] trend1d reads x,y [and w] values from the first two [three] columns on standard input [or xy [ w ] file ] and fits a regression model y = f(x) + e by [weighted] least squares. ... E.g., a robust quadratic model is -N 3 r . ...