Basic astrometry – simple plate reduction.
It is designed to allow the non-specialist to get good results with a minimum of trouble and esoteric knowledge. You supply a text file containing information about the exposure and the positions of reference and unknown stars; it performs the various coordinate transformation and fitting operations required, displays a synopsis report on your terminal, and prepares a detailed report for printing.
We describe the autoastrom package, which provides an interface to the ASTROM application. This creates a semi-automatic route to doing astrometry on CCD images.
THIS IS BETA SOFTWARE. Some features work only partially or unreliably. It does not have all the functionality of a production release. The interface may well change.
Starlink’s ASTROM application provides powerful astrometry facilities, for analysing astronomical images; it is, however, rather cumbersome to use. As described in SUN/5, ASTROM can:
Autoastrom provides a shell around ASTROM so that, as well as the core astrometric facilities of ASTROM, autoastrom will:
Plot star fields (positions, magnitudes, and other data) from the CSI79, SAO, AGK3, PERTH70, and Dixon non-stellar objects catalogues.
CHART is not distributed on Starlink CDs but it may remain as a legacy package at UK Starlink sites. There is no Linux port an little support available. CHART will be superceeded by facilities in CURSA in the near future.
You can specify a series of search areas, place magnitude or total number limits on the search, and chose which source catalogues to include or exclude. After the search is made, you may list the results at a terminal or on a printer. Positional information may be precessed to a specified equinox. In the case of astrometric data, proper motions may be applied up to a specified epoch.
You can plot the results in the form of an overlay or finding chart. Extra objects, i.e. with positions supplied by you, may be added to the plot at this stage. The plot may be made on any GKS device, and a number of different plot options are available, such as scale and area, an RA and Dec coordinate grid, and various forms of error box.
You may also use the results as input to an astrometry program, i.e. it can be used to select astrometric stars as positional references. In this case, you will be asked to supply x,y positions for the reference stars from a measuring machine, and can then convert unknown x,y positions to RA, Dec or vice versa. ASTROM performs the actual astrometry, from within CHART if necessary.
Convert star coordinates from one system to another.
Both the improved IAU system, post-1976, and the old pre-1976 system are supported. It can transform between the following coordinate systems:
The input/output arrangements are flexible to allow a variety of operating styles: interactive, input from a file, report to a file, batch, etc. Also, in addition to the report which is produced, the results are available in raw form, to a fixed resolution, and free from extraneous formatting; this file is intended to be read easily by other programs.
It offers control over report resolution, and has simple online help. All input is free-format, and defaults are provided where this is meaningful.
In order to comply with the IAU 1976 recommendations, all position data published from 1984 on should be given in the new system, using equinox J2000.0. However, for years to come, positions will frequently be given in the old system, using equinox B1950.0. Discriminating astronomers and astrophysicists are best advised to give both B1950 and J2000 positions for sources mentioned in their publications; the conversion can be done using COCO.
Plan observations with either the Utrecht échelle spectrograph (UES) or the UCL coudé échelle spectrograph (UCLES).
It can be run at your home institution, when preparing an observing proposal, or before or during an observing run.
It lets you view interactively that part of the spectrum which will fall on the detector for a given central wavelength. This is achieved by drawing a complete échellogram in an X-window, along with a box representing the exact size and shape of the detector. The positions of individual spectral lines can also be marked on the display. You can then move the detector window around by moving a crosshair cursor to the desired centre of the detector, and then clicking the left-hand mouse button to set the detector position, or else by explicitly specifying the desired central wavelength. At each position the screen displays the minimum, central, and maximum wavelengths and order numbers falling on the detector, as well as an estimate of the length of the detector (in Angstroms). The position of the box can be marked on the screen, so as to ease preparation of observations where multiple overlapping wavelength ranges are required. You can also save the current detector position in a text file.
Finding the Coordinates of a Named Object.
FINDCOORDS is a new utility for using the name of an astronomical object to look up its equatorial coordinates. You simply enter the name of the object and its coordinates are displayed. Type:
For example:
If the name is recognised then the equatorial coordinates of the object will be displayed. The Right Ascension is shown in sexagesimal hours and the Declination in sexagesimal degrees; both are for equinox J2000.
FINDCOORDS works by submitting a remote query via the Internet to the version of the SIMBAD name-resolver provided by ESO (the basic SIMBAD is maintained by the Centre de Donnees astronomiques de Strasbourg, CDS). Consequently, findcoords will only work on computers with a suitable Internet connection. Also, the name given must be recognised by SIMBAD, though the latter’s dictionary of names is very extensive.
HDS file editing and manipulating tools.
HDSTOOLS is a suite of tools for editing and manipulating HDS files. They are updated versions of the tools once available in the ASTERIX package. The following tools are available:
List the contents of an HDS data structure.
The Hierarchical Data System (HDS) is one of the most popular features of the Starlink environment as it enables associated data items to be stored together in a single file, but in a structured fashion.
Finding Guide Stars for use with NAOMI on the WHT.
The NAOS package may be used to find guide stars suitable for use with the NAOMI adaptive optics system available on the William Hershell Telescope (WHT) on La Palma.
NAOMI usually requires a relatively bright guide star located close to the target object being observed. You prepare a list of potential target objects and NAOS remotely searches a version of the USNO PMM astrometric catalogue to find suitable guide stars for these targets. You would usually use NAOS at your home institution prior to travelling to La Palma to observe with NAOMI.
Show the observability of a star through the year from a given geographical location.
It generates a plot that shows, for a complete year the:
List the components, in a given direction, of the observer’s velocity on a given date.
This allows an observed radial velocity to be referred to an appropriate standard of rest. It also computes light time components to the Sun, allowing the times of phenomena observed from a terrestrial observatory to be referred to a heliocentric frame of reference.
The accuracies, of better than and , are adequate for most classes of work, the notable exception being some pulsar observations.
The input/output arrangements are flexible to allow a variety of operating styles: interactive, input from a file, batch, etc. All input is free-format. The normal operating style is interactive: prompts appear on a terminal, data are entered specifying the report required, and a listing is sent to disk for later printing.
Almanac and calculator – interactive.
This consists of two programs:
Both programs have several preset Observatory locations to choose from. You can also specify your own.
Search Starlink document and keyword indexes for a specified keyword.
You can display or print any document that is found. Unfortunately, it will not print LATEX documents in a satisfactory form. Thus, its main use is to find documents, not print them. Stocks of Starlink Notes and Papers are kept at every Starlink site, so you can get a paper copy.
It has been superseded by the more powerful showme and findme commands provided by the HTX
utility.
Look up information needed to send e-mail.
The program searches the Starlink user database and the on-line World E-mail Guide for usernames and sitenames.
Starlink’s conferencing software.
It is based on the World Wide Web and provides similar capabilities under Unix to those provided by the DEC product VAXnotes under VMS. Its main features are that it:
Users can both read existing notes and submit new ones. One difference to VAXnotes is that while VAXnotes could maintain an index of all Conferences, even when they were located on separate systems at several Starlink sites, FORUM maintains an index only for each instance of FORUM.
Java Runtime Environment.
JRE is a copy of the standard Java Runtime Environment which has been wrapped to allow installation in the Starlink software. The JRE is included to provide a standard stable base on which to base Starlink Java tools.
Starlink’s News service.
Just type news and follow the instructions.
A language for manipulating text, files, and processes easily.
It provides a more concise and readable way to do many jobs that were formerly accomplished (with difficulty) by programming in the C language or one of the shells. There are several O’Reilly books on Perl that will help you understand and use it. Learning Perl and Programming perl are two of these books. Chapter 39 of Unix Power Tools gives an introduction to Perl.
Additional CPAN modules for the Perl package
PERLMODS is a package of additional modules from CPAN (Comprehensive Perl Archive Network) which are added to the standard PERL installation to provide extra facilities needed by the STARPERL modules and by the SURF package.
Read e-mail.
Just type pine to start it. A lot of on-line help is available.
Build and maintain a database of Starlink users.
Used by Starlink Site Managers to manage their user lists.
Additional modules for the Perl package
STARPERL is a package of additional Starlink modules which are added to the standard PERL installation to provide facilities such as NDF access (NDFPERL).
Get output from an X-client to display on the screen of your X-terminal.
In other words, it provides an easy way to use remote X windows.
Convert Ascii format files to PostScript format for printing on PostScript printers.
This gives a nicer looking output.
A powerful text editor with many advanced customizable features.
It is fairly easy to make it emulate EDT and EVE. This makes it convenient for users familiar with these VAX/VMS editors.
PostScript interpreter.
This provides:
Hypertext cross-reference utilities.
These are used to maintain large sets of documents which use HTML, the Hypertext Markup Language. They can also form the basis for hypertext help systems for other software. There are three components:
Check spelling.
A screen-oriented spell-checker that shows spelling errors in the context of the original file, and suggests possible corrections when it can figure them out.
Edit text.
A text editor which provides a reasonably good emulation of EDT, together with a few extra facilities such as cut-and-paste of rectangular regions, unlimited undo, horizontal scroll, and display of two or more windows.
Convert LATEX to HTML.
LATEX2HTML is now included in the STAR2HTML package.
Processes LATEX source files into a set of Hypertext Markup Language (HTML) files, suitable for browsing with hypertext viewers and web browsers.
Process text.
A fully programmable text processing utility. It can build new text processors and batch-oriented text manipulation routines. Its main value for Starlink users is its close emulation of EDT.
Merge PostScript files.
Merges one or more EPSFs into a single PostScript file. An EPSF (Encapsulated PostScript File) is a PostScript file structured so that it can be incorporated or included into another PostScript file (so that, for example, a diagram created with a graphics application can be inserted into a text document created with a word processor).
Input files can be individually rotated, scaled, and shifted. Output files can be either EPSF or ‘normal’ PostScript suitable for a printer. This allows:
Convert Starlink documents to Hypertext.
Processes Starlink document LATEX source files into a set of Hypertext Markup Language (HTML) files, suitable for browsing with hypertext viewers and web browsers.
This is a major component of Starlink’s system for producing hypertext documents, which also includes TEX,
HTX, GHOSTSCRIPT, the dvips processor, and PERL.
The processing to hypertext is performed by LATEX2HTML which is bundled with STAR2HTML.
LATEX2HTML is not used directly becuase Starlink documents use a series of additional macros to allow
inter-document cross referencing within the Starlink document collection.
Produce high quality text and diagrams by type-setting.
LATEX is a document preparation system based on TEX, but easier to use. The current versions are TEX v3.1415 and LATEX2e (Dec 1994). The final output is usually produced by a laser printer.
Starlink recommends that you create your documents using LATEX2e with formats based on skeleton files
such as /star/docs/sun.tex.
SUN/12 is a cookbook showing how to generate common kinds of format using LATEX; this is a quick way to learn how to use it. SGP/28 and SGP/50 give advice on how to produce documents in a suitable style for Starlink.
Detect errors in Fortran 77 source code, especially mistakes that tend to be missed by compilers and linkers.
Probably its most valuable feature is the careful checks it performs on subprogram interfaces. It
examines the actual arguments in each CALL statement (or FUNCTION call) and compares them with the
corresponding formal arguments of the SUBROUTINE (or FUNCTION) subprogram. It warns of mismatches in
the number of arguments, and incompatibilities in the data type and dimensions of each one. It
also checks that arguments used before being set in a subprogram have defined values on entry,
and correspondingly that arguments are set on exit when their values are used later in the calling
program.
The GNU C compiler.
Support generic subroutines.
Preprocesses a generic Fortran subroutine – one written to cover several different data types – into one routine per data type, and concatenates these routines into a file. The file is then compiled by the Fortran compiler to produce an object module.
Associate error messages with status values returned by Starlink infrastructure routines.
This works in conjunction with the Starlink Error Message Service (EMS). It enables more informative error messages to be sent to the user.
Improve the structure of the source code of a poorly organised Fortran program.
SPAG is commercial software and is not distributed on Starlink CDs. Access is available to registered Starlink users on the
central service machine at RAL – contact Hiten Patel (hiten@star.rl.ac.uk) for access.
‘SPAG’ stands for ‘Spaghetti Unscrambler.’ It re-orders blocks of statements in such a way that the structure of the code is improved, while remaining logically equivalent to the original program. The result improves the readability and maintainability of badly-written Fortran code. It is marketed by Polyhedron Software.
Software porting tools.
A set of tools to convert code between operating systems (principally between VMS and Unix, and between different flavours of Unix). They:
INCLUDE statements and ‘escape’ backslash characters.
The output file on VMS is in Stream_lf format so it can be read on Unix systems using NFS.
INCLUDE files, thereby providing a machine-independent way of writing INCLUDE
statements.Link X libraries.
A Starlink environment package that provides a system-independent method of linking with X libraries. This relieves other libraries and applications from having to worry about the various complications involved. It allows the X library linking strategy to be changed easily, without changing any of the other Starlink environment components.