David's Astronomy Pages
'VMA' Program - Variable Star Magnitude Analysis

Bullet Introduction
Bullet Screen Shot
Bullet Program Details


"Vma_Program" is a hypertext application (hta) than runs Visual Basic scripts to analyses batches of FITS images and measures the magnitude brightness of variable stars at one or more filter bands.

The program accesses a pre-prepared Reference File which lists the variable stars under analysis, together with their reference stars, and then uses 'TheSky' & 'CCDSoft' (Software Bisque) to locate the position of the Variable & Reference Stars in each image and measure magnitudes. Results are written to a tab delimited file which can be easily imported into Excel.

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Screen Shot


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Program Details 



Name : Variable Star Magnitude Analysis

;* Program : vma_Application.hta
Version : 1.2 
Build : Build A (for CCDSoft 5.00.99) &
Build : Build B (for CCDSoft 5.00.77)
Date : 2003-05-13

Language : Html/hta and Visual Basic Script
Author : David Richards, Dorset, UK (2003)
Email : 
WebSite : http://www.richweb.f9.co.uk/astro

Info : vma_readme.txt
Online : http://www.richweb.f9.co.uk/astro/vma_program.htm
Files : vma_Application.hta - Main Application (HTA)
vma_Scripts.vb - Analysis routines/Scripts (VB)
vma_Support.vb - Support routines (VB)
vma_Setup.ini - Saved Settings 
vma_Icon.bmp - Program icon
vma_Readme.txt - Readme file
vma_Log.log - Logfile file
example_reference_data.txt - Example Reference File
example_photometry_results.dat - Example Tab-delimited Results File

Calls CCDSoft & TheSky (Software Bisque)

Testing : Build A has been tested with TheSky 5.00.100, 
CCDSoft 5.00.99 & Internet Explorer 6 on a 700 MHz 
Laptop running Windows XP Home.
Build B has not been explicitly tested, but should work based on
earlier versions and the single code line change involved.

1) Open ZIPPED file and extract files to a folder of your choice
use either "vma_program_1.2_BuildA_for_CCDSoft5.00.99.zip"
or "vma_program_1.2_BuildB_for_CCDSoft5.00.77.zip" 
2) Read notes in "README" file
3) Install Windows Script Host (vn 5) if required
To install the latest version of Microsoft Windows Script Host (WSH), 
go to Microsoft Windows Script Host [http://msdn.microsoft.com/scripting/]
> Windows Scripting Host > Downloads. 
Follow the installation instructions. 
Alternatively, run ste50en.exe from the "Orchestrate" folder.
4) Copy "REFERENCE_DATA" file and edit to insert details of variables 
star targets, along with corresponding C,K Reference Stars + Mags
(* Be careful not to change format /columns positions in the Reference file)

1) Create a WORK FOLDER and place reduced FIT files into appropriate
subfolders, one BAND SUBFOLDER for each filter band (eg V Cal, R Cal)
2) Check that REFERENCE DATA file includes the Variables Stars you wish to analyse
and that Reference Star details and magnitudes are correct
3) RUN program "vma_Application.hta" 
It should run ok whether TheSky & CCDSoft are already open or not
(You might need to relax Internet Explorer Security settings)
4) EDIT the following fields as required 
Work Folder - Full pathname for Parent Folder 
(this is the folder that will contain Band Subfolders
and where results will be placed)
Reference File - Full pathname to reference file with C,K Stars, Mags etc
Image Scale - in arc sec/pixel (e.g. 3.354)
Results File - name of file for results (filepath not required)
V - Checkbox and name of V Band Subfolder
R - Checkbox and name of R Band Subfolder if used
B - Checkbox and name of B Band Subfolder if used
I - Checkbox and name of I Band Subfolder if used
U - Checkbox and name of U Band Subfolder if used

5) Click on SAVE button to save your settings ready for next time
6) Click on START ANALYSIS button
7) Check LOG file on first run and whenever problems are reported
Most likely problems relate to a mistyped name in Reference File or 
problem extracting a variable magnitude due to inaccurate catalog position 
for the variable. Insert equivalent GSC or SAO star name as V_AltName 
in the Reference File to overcome this problem (1 in 4 stars need this). 
Then rerun script
(Note that new result/logs are appended to RESULTS and LOG files.
Delete these files manually to start'clean'.
8) Locate RESULTS file"in Work Folder and import into EXCEL or other application 
(file is Tab-delimited to aid this task)
9) Compare results with those expected
Consider whether any refinements to parameter values in 
CCDSoft's Source Extraction setup are required or not

NOTES (MagVarAnalysis) 

1)The Format of the SETUP and REFERENCE DATA files should not be changed.
Doing so could cause the program to stop working correctly or crash.
2)The catalog positions of certain GCVS variable stars are inaccurate
and for these stars the script cannot directly take a magnitude reading.
This problem is easily solved by defining the star's GSC or SAO equivalent 
name in the REFERENCE DATA file. This allows the script to use more 
accurate position coordinates 
3)The script will automatically InsertWCS into analysed FITS images, 
so this could be a step that could be dropped from regular processing
4)The MagVarAnalysis PROGRAM CODE (HTA and VB) is part of a larger program
code set and most non-required subroutines have been removed from this 
code subset. Certain references to these removed routines may remain in 
the code, but testing shows that these shouldn't effect program execution. 

Similarly there are certain program variables, objects and constants 
which are defined in code headings, but are not actually used.

' ********************************************************************
NOTES (Telescope Operation) 

1)When using the full script for unattended telescope control and image 
acquisition you should be aware of potential risks to equipment and
telescope. (Please see disclainer below)
You are advised to only operate these scripts unattended when you are 
completely familiar with the working's of these scripts and
their operation with your scope / your setup / your versions TheSky/CCDSoft

2)Image acquisition and telescope control (routines within full 
script version have been developed and tested on the author's own
non-HPP LX200 Scope / ST7e camera. 


2003-05-13 Release of version 1.2 (Build B). As per Build A, but works with 
older version of (CCDSoft 5.00.77)
(uses 'Image.Scale' instead of 'Image.ScaleInArcsecondsPerPixel')

2003-05-13 Release of version 1.2 (Build A), with bug fixes and more robust 
interface and improved data validation. Works with CCDSoft 5.00.99
Enhancements : - Extraction and output of AIRMASS from Fits Header 
Updates : - Updates to make code compatible with CCDSoft 5.00.99
- Image.Scale changed to Image.ScaleInArcsecondsPerPixel
Bug fixes : - Check boxes now turn on/off the analysis of specific bands
- Analysis can now be repeated without error message

2003-02-12 Release of version 1.1 with revised inteface using HTA 
(Hypertext Application) and including support for additional
bands U, B, I) and multiple variables star analysis per CCD frame
Code tested against CCDSoft 5.00.75 beta, TheSky 5.00.40 beta
and Internet Explorer 6
2003-01-24 Release of "Variable Star magnitude analysis" code subset (1.0)
for appraisal by Dale Mais, San Diego, CA.
2003-01-23: Code review and modification to DMais routines using 
V & R FITS files supplied by D.Mais
2003-01-04 Development of Variable Star Magnitude Analysis scripts
2002-11-01 First code concepts using Visual Basic scripting of CCD and Telescope
operation using TheSky and CCDSoft


1)The Script may be freely used by fellow amateur astonomers, 
(feedback via email address listed above would be very much appreciated)
2)Script components may be modified or incorporated into your own script, 
but not distributed without express permission of this author and not 
without full acknowledgement
3)The Script must not be used for any form of commercial use or gain


1)Some of the initial insights into creating VB scripts to control
Telescope and CCD Camera, came from code examples from Software Bisque
Original code from Software Bisque has been significantly amended/extended
and is not considered to infringe Copyright.
2)Script functionality was widened through communications and discussions 
with a number of people, including Dale Mais


Telescopes do not have an unlimited range of movement. The type of 
telescope, type of mount, and size and position of accessories can 
prevent it pointing in certain directions. If the telescope is forced
past these points, the telescope, it's mounting or accessories (such as 
an attached CCD Camera) might be damaged. 
Whilst this script operates with TheSky (which includes a "limit line" 
feature to specify inaccessible positions) and has some independent safety 
features, any telescope could run past its mechanical limits through 
accident or carelessness or component failure. With unattended 
operation and the dependance on correct content and formatting of user 
supplied target data, the potential risk is higher still.

The author (David Richards) therefore cannot be responsible for any 
damage to any telescope or equipment that occurs when using this script 
or any modifed derivative.


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