... Stellar Evolution is driven entirely by the never ending battle between Pressure and Gravity . As imbalances are reached, the star is driven to find a new Energy source. ... Pressure and gravitational forces are equal, the star is stable and its core is sufficiently hot to fuse Hydrogen into Helium More about main sequence stars . ... The luminosity generated by the core fusion of Helium into Carbon is far greater than the shell luminosity associated with the fusion of Hydrogen into Helium. ...

... Telescopes . ... CCD photometer . ... One of the principal devices used in observations at the telescope Zeiss-1000 is a CCD photometer. ... The count rates (electron per second) for ADU = 1e - computed throughout the image for U = B = R = I = 20.0 for an object observed at air mass equal to 1.0 with the given version of CCD at the telescope Zeiss-1000 are presented in Table 1. Table 1: Quantum efficiency and count rate in the broad-band system of the CCD photometer of the telescope Zeiss-1000. ...

... Standard magnitudes can only be computed for the U, B and V filters and hence the only standard colours that can be calculated are U-B, B-V and U-V. An important point to note, is that these standard colours can be computed using the following instrumental colours - U-B, B-V, U-V, (UVW1-U), (UVW1-B), (UVW1-V), (UVW2-B) and (UVW2-V). ... The program loops through these colours and if the relevant instrumental magnitudes are present computes the standard magnitudes and standard colour. ...

The Agile window provides complete control over the Agile high-speed photometer. ... All other parameters are specified as part of the command that starts an exposure sequence. ... To connect the filter wheel controller, issue this command in the command bar at the bottom of the Log window: agile connDev fw . ... To home the filter wheel controller, issue this command in the command bar at the bottom of the Log window: agile fwhome (there must be a filter wheel mounted in Agile for homing to succeed). ...

An improved correlator for ALMA has been proposed by an European consortium including Astron (NL), Bordeaux University (FR), IRAM (FR) and Arcetri. ... The work in Arcetri has focused on the efficent design of a digital receiver, that exploits the peculiarities of the astronomical signal, i.e. the extremely coarse quantization and the stochastic nature of the input signal. ... A complex mixer followed by a two stage bandpass filter. ... Phase effects in a hybrid correlator . ...

... The absolute flux calibration of NICMOS will be calculated from observations of standard stars with known flux distributions F( ). ... In order to expand the set of IR standard stars in the appropriate flux range for NICMOS, M. Rieke, R. Thompson, and collaborators at the University of Arizona are making photometric observations of solar-analog stars, which will be used to normalize the solar spectrum to the observed IR magnitudes. ... Relative flux references accurate to 1.5% for standard...

... The first step to improve the FORS calibration is therefore to obtain data to allow a computation of the illumination correction across the field. ... Another limitation on the calibration accuracy has been the brightness of the Landolt standards which have forced the use of extremely short exposures introducing small but non-negligible shutter-time errors and also resulting in a very small number of useful standards per frame. ...

Next: Hierarchical Wiener filtering Up: Noise reduction from Previous: The convolution from . Let us consider a measured wavelet coefficient at the scale i . We assume that its value, at a given scale and a given position, results from a noisy process, with a Gaussian distribution with a mathematical expectation , and a standard deviation : . ... We get: . ... This is done from the study of the variation of the noise between two scales, with an hypothesis of a white gaussian noise; . ...

... Superb optical performance coupled with time proven computerized pointing and tracking has made the LX200 ACF series a best-seller in the high-performance telescope class. ... MeadeтАЩs new LX70 Series offers high-quality German equatorially mounted telescopes with slow-motion controls and heavy-duty steel tripods. ... For crisp wide-field observing and imaging, few optical designs match the performance of a true triple-element apochromatic refractor. ... Meade Standard Field Tripod #07020. ...

... I have compiled a list of throughput filter curves from a variety of telescopes, instruments, and surveys. Click on the name of the filter to download it. The first line of each filter is the zeropoint for that filter. If the filter is in the AB system, it is listed as 0.0 (or in otherwords -48.55). ... Filter . Effective Wavelength . ... A_V . ... 0.987 . ... 0.050 . ...

12feb07 Measuring the SEFD around 1100 Mhz . ... bandpass filter low frequency falloff around 1130 Mhz . ... A 500 Mhz bandpass centered on 1100 Mhz (via the spectrum analyzer) showed a 6 db difference between 1100 Mhz and the noise floor at 1000 Mhz. ... The interim correlator was used with 25 Mhz bands centered at: 1040, 1060, 1080, and 1100 Mhz. ... 1040 Mhz cfr trking src(.gif) There is probably not very much sky signal getting into this band so it looks better than it should. ...

RTT150 . Russian-Turkish 1.5-m Telescope . ... Until 2002 observations were mostly performed with ST-8E CCD in the 1:7.7 Cassegrain focus. ... In April, 2003 telescope was equipped with a larger-size CCD Andor DW436 . ... 2048 x 2048 pixels, . ... Since summer of 2002 the main focal detector of the RTT150 telescope was AP47p CCD in 1:7.7 Cassegrain focus. ... During September 3-13, 2002 works on installation of new autoguiding system ( photo 1 ) were carried out on RTT150 telescope. ...

A computer controlled low light photometer for nightglow observations. Hardware units of portable photometer for low light measurements, especially night glow emission is described. ... Interface card contain three channels of 24 bit counter, 4 channels of 12 bit ADC and the buffer bus for the controlled motors of the altazimuthal fork mounting and filters wheel, the position encoders. ... Where N( ) is output signal photometer generated input light flux F( l ) . ... PMT # . 599 . ...

... The New 1997 IEEE Standards Products Catalog features the complete listing of standards publica-tions and services IEEE Standards offers, along with the information you need to place your order. ... Books and Other Products on Standards - contains a detailed listing of informative print and electronic publications relevant to standards and their implementation in areas of electrical engineering, electronics and computer technology. ... IEEE Standards Products Listing 22 . ... Power Electronics 41 . ...

This document is the Table of Contents for Funtools. ... The Funtools library provides simplified access to a wide array of file types: standard astronomical FITS images and binary tables, raw arrays and binary event lists, and even tables of ASCII column data. ... funimage: create a FITS image from a Funtools data file . ... funtable: copy selected rows from a Funtools file to a FITS binary table . ... Funtools Data Files . ... Binning FITS Binary Tables and Non-FITS Event Files . ...

... We describe a tool in the PCIPS environment for finishing the job of globular cluster photometry started by DAOPHOT II: starting with the instrumental magnitudes derived by DAOPHOT II, DASHA can automatically produce final color-magnitude diagrams. ... DASHA can automate the whole process of globular cluster photometry, from instrumental magnitude lists produced by DAOPHOT II, to final color-magnitude diagrams. ... DASHA is oriented towards star lists produced by DAOPHOT II as source data. ...

... PmWiki .Forms$:Audience} . ... An optional name="FormName" argument can be used to name the form. ... input text name value size= n :) (:input hidden name value :) (:input password name value :) (:input radio name value :) (:input checkbox name value :) (:input select name value label :) (:input default default-name default-value :) (:input submit name value :) (:input textarea name [=value=] rows= n cols= n :) (:input reset name label :) (:input file name label :) (:input image name "src" alt :) . ...

blockmean - filter to block average (x,y,z) data by L2 norm blockmean [ xyz [ w ] file ( s ) ] -I x _ inc [ m|c ][/ y _ inc [ m|c ]] -R west / east / south / north [ r ] [ -H [ nrec ] ] [ -N ] [ -V ] [ -W [ io ] ] [ -: ] [ -bi [ s ][ n ] ] [ -bo [ s ] ] blockmean reads arbitrarily located (x,y,z) triples [or optionally weighted quadruples (x,y,z,w)] from standard input [or xyz [ w ] file ( s )] and writes to standard ... Default is (longitude,latitude)]. -bi Selects binary input. ...

... This method is called once when the filter is loaded. ... This method should return a flag word that specifies the filters capabilities. ... With CONVERT_TO_FLOAT, the filter is called with the image data converted to a FloatProcessor (3 times per image for RGB images). ImageJ will lock the image before calling this method and unlock it when the filter is finished. For PlugInFilters specifying the NO_IMAGE_REQUIRED flag and not the DONE flag, run(ip) is called once with the argument null . ...

This library currently provides subroutines used to transform theoretical spectra to intermediate and broad-band photometric indices. ... Typical tasks are the response functions and transmission curves for various filters, mirrors and photomultiplier windows. ... The response is zero outside the given wavelength range. ... real . input . Wavelength in nanometres . PHOT_1P21 . ... PHOT_AIR . ... PHOT_ALUM . ... Inputs must be valid as for PHOT_FILTER, PHOT_AIR, PHOT_ALUM and PHOT_1P21. ...