Instrument Summary -- Why Use the GHRS? Here we provide a brief overview of the basic properties of the GHRS. ... The GHRS can obtain spectra from about 1150 to 3200 . ... The repeatability of fluxes is even better, being better than 1%; i.e., it is possible to compare measures of the same wavelength in the same star at different times to within 1% for observations with the LSA. ... The source to be observed may be placed in a Large Science Aperture (LSA) or a Small Science Aperture (SSA). ...

. Next: A Quick Look Up: Spectral-Line Observing at AO Previous: THE SOURCE LIST . This section describes using the AO-Control GUI - a graphical user interface (GUI) to the Arecibo observing/datataking system - for spectral line observations. If you would like more information on the general properties of the GUI, go to http://www.naic.edu/ aoui . Subsections . A Quick Look . The Details . Useful Stuff . koneil@naic.edu

... A total of 19 standard observing bands are defined at the VLA. ... The tables below describe the bands. ... VLA STANDARD BANDS - VLA SYNTHESIZER SETTINGS VLABAND VLAFEAB VLAFECD VLASYNA VLASYNB FLUKEA FLUKEB FEFILT CC 0.00 0.00 3860.1 3810.1 100.00000 200.00000 0000 UU 19.60 19.60 3610.1 3660.1 100.00000 200.00000 0000 KK 17.60 17.60 3860.1 3810.1 100.00000 200.00000 0000 LL - 3.20 - 3.20 3639.9 3560.1 100.00000 200.00000 0000 XX 13.40 13.40 3939.9 3889.9 ...

... 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. ...

... 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. ...

... Binary large object. ... CGI is a popular interface used to create server-based web applications with languages such as Perl or C. A web browser, such as Netscape Navigator. ... Core JavaScript contains a core set of objects, such as Array , Date , and Math , and a core set of language elements such as operators, control structures, and statements. ... A JavaScript primitive value is a member of one of the following types: undefined , null , Boolean , number , or string . ... World Wide Web . ...

... News Latest News News Archive Newsletter Quarterly Status Report . ... Calibration strategy, status and factors limiting success: Chandra . ... Calibration strategy, status and factors limiting success: XMM-Newton . ... Calibration strategy, status and factors limiting success: Swift . ... Calibration strategy, status and factors limiting success: RXTE . ... Calibration strategy, status and factors limiting success: Suzaku . ... Calibration strategy, status and factors limiting success: Integral . ...

... 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. ...

... The material in "From Stargazers to Starships" meets several important requirements of the national standards. Pages cited below are from National Science Education Standards National Academy Press, Washington 1995. ... For example: the sections on astronomy not only describe calendars and sundials (including their construction), but also the astronomy of the ancient Greeks, including two different ways in which ancient Greeks estimated the distance to the Moon. ...

Emission Line Diagnostics in a ``No UV Bump'' Quasar PHL909 Smita Mathur, Belinda Wilkes, Martin Elvis and Jonathan McDowell Abstract PHL909 is a quasar with unusually low ultraviolet luminosity (blue bump strength C UV=IR = \Gamma0:20 compared to an average value of 0:4 (McDowell et al. ... The intrinsic continuum of PHL909 ( i.e. as seen by the BELR ) may thus be similar to the `standard' continuum, with a big blue bump, reddened along the line of sight. ...

... Fortranљ66 . ... Fixed form . ... Whole Fortranљ66 . ... Continuation line indicated in column 6 . ... Blank line as comment . ... Extension in Unix .f .f .f .f90 .f .f90 . Extension in DOS .FOR .FOR .FOR .F90 .FOR .F90 . ... This applies to both fixed form and free form source code. ... Fixed form of the source code is discouraged in Fortran 95! ... In UNIX there is no concept called extension, and the extensions are not specified in the Fortran standard, but in informal manufacturer standards. ...

Next: Stars Up: File Formats Required Previous: File Formats Required . ... It is not so obvious that planning and reducing photometric observations also require information about the telescope used. ... This information is needed both for planning observations and reducing data. ... Many instrumental details influence the methods that must be used in reducing photometric observations, because the data-reduction process must accurately model the instrument's performance. ... Instrumental data . ...

... every new catalog of objects has to be contained in the UNIX directory having the same name as the catalog of objects; . ... the programs for local operations (programs of low level) with the catalog of objects are also in the same directory; . brief characteristics and names of the programs and file with the description of the catalog are stored in the file cats_descr ; . ... All astronomical catalogs have a different format and list different observables. ...

... 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. ...

Home . ... Observing . Exposure Time Calculator (ETC) . Survey processing . ... ESO - Public Surveys . near IR surveys . ... Exposure Time Calculator . ... Survey Area Definition Tool . Recommended values for Detector Integration Time (DIT) . ... Detector Properties . ... Filter properties . ... ESO ][ VISTA Home ] ...

Databases (NSDC) of the Natural Planetary Satellites. ... NSDC: Database of astrometric observations of Natural Planetary Satellites . ... They are thoroughly looking for observations in different sources, creating their owndatabases which are then mostly inaccessible to other researchers. ... In the file "content" with explications, the reference is given to the data source as well as the bibliographic reference. ... Data sources. ... Why a specific bibliographic database for Natural satellites? ...

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. ...

... Up: Proposal Processing . ... ESO is prototyping a distributed ``Phase II'' system that will allow astronomers to prepare their observations at their home institutions, while maintaining a central repository for all observation data. ... ESO is developing a Phase II Proposal Preparation system (P2PP) to collect detailed scientific programme descriptions, in the form of observation blocks (OB). ... ESO's Phase II Proposal Preparation system is an integral part of the VLT Data Flow System (DFS). ...

Next: Extinction efficiencies: general behaviour Up: Optical properties of cosmic Previous: Optical properties of cosmic . It is now evident that observed interstellar extinction cannot be explain using particles of only one kind. ... The intensity of radiation after passing a dust cloud is equal to . ... The interstellar extinction is . ... Next: Extinction efficiencies: general behaviour Up: Optical properties of cosmic Previous: Optical properties of cosmic root 2003-04-09 ...

Last updated 5 November 2003 by JMD . Last link checked 9 October 2003 by JCB . Data from 191 observations of stars with the ARCES were analyzed to calculate exposure times to reach particular signal-to-noise values for bright standard stars. ... An exponential fit to the data shows pretty good agreement and allows for forecasting to fainter stars beyond the limit of the data set ( V ~ 12). The fit was used to calculate the exposure times in the table below: . ...