Software Programs for Variable Star Observers
Last update : February 1st, 2013
Two software programs here presented could help the Amateur Variable Star
Observers in their activities.
LesvePhotometry is an automatic photometry tool.
PeriodVSOplanner helps you in the observation planning of periodic variable stars.
They are provided as Freeware programs and do not require any registration key.
Nevertheless in order to evaluate the success of these programs, I would be pleased
if you let me know your interest.
A discussion group has been open on Yahoo, join : http://tech.groups.yahoo.com/group/lesvephotometry/
LesvePhotometry
Description
LesvePhotometry is based on differential photometry, the more common photometry method used by amateurs.
In differential photometry, we compare the amounts of light from the
target star (variable star) and comparison stars.
The different steps to measure the magnitude of star from a CCD image are :
- detection of target and comparison stars on the CCD image
- calculation of the average pixel values in a circular apertures around the star and in annulus (to measure the sky background)
- calculate the magnitude of the target star from
- the aperture measurements
- catalog magnitudes of comparison stars
With common photometry programs, the user has to
select manually the target and comparison stars (on the first image of a series)
enter the catalog magnitudes of comparison stars.
He has to repeat these operations each time a new photometry is launched.
In LesvePhotometry, following data are provided once by the user and stored in a database:
target star
- Name
- Right Ascension, Declination
- Names of comparison stars
- an other parameters
comparison stars
- Name
- Right Ascension, Declination
- Catalog star magnitudes for B, V, R and I filters
- an other parameters
Each time a photometry is launched, the program automatically :
- retrieves the needed data from the database
- solves the image by astrometry
- locates stars and positions the aperture circles
- calculates the magnitude of the target star
The results are provided in three reports: AAVSO format, CBA format and Excel file with a chart.
The program provides an easy human interface for the star database maintenance.
Installation information
The database engine (SQLite.Net) is integrated in the program and all the needed files are included in the setup program.
An example of database is included in the setup program.
The locations of target and comparison stars on each image plates are obtained with PinPoint astrometry engine.
To use PinPoint astrometry engine, you need the appropriate license from dc3.com
See http://pinpoint.dc3.com
Note for MaximDL users
The PinPoint "Light Edition" included in Diffraction Limited's MaximDL does not support scripts and will not work with LesvePhotometry. If you have MaximDL you have to upgrade to the "full" PinPoint license. Additional capabilities are available with the full version of PinPoint, which is also compatible with MaximDL.
The ASCOM platform (version 5.5 or higher) is required by PinPoint and LesvePhotometry,
free download at http://ascom-standards.org/
The .NET Framework 4 must be installed, free download from Microsoft website.
The photometry results are also presented in an Excel file, Office Excel version 2003 or later is required.
LesvePhotometry program has been tested on WindowsXP and Windows7 operating systems.
Two directories are used for installation
C:\Program Files\Common Files\DPP Lesve\ (for XP)
or
C:\Program Files(x86)\Common Files\DPP Lesve\ (for Win7)
contains the program and needed files (don't modify them)
C:\Documents and Settings\yourUserAccount\DPP Lesve\ (for XP)
or
C:\Users\yourUserAccount\Documents\DPP Lesve (for Win7)
contains a working copy of the database (VS_Database.db3)
If you are curious, the user parameters are stored in a General Driver of ASCOM Profile (use the ASCOM Profile Explorer to inspect the parameters)
C:\Documents and Settings\All Users\Application Data\ASCOM (for XP)
or
C:\ProgramData\ASCOM\ (for Win7)
Known issues
For an unknown reason, the DPP_AstroFunctions.dll is not always registered correctly.
You will find in the directory
C:\Program Files\Common Files\DPP Lesve\Utilities
or
C:\Program Files(x86)\Common Files\DPP Lesve\Utilities
two batch files to register the dll file in both OS (XP or Win7):
Add2GACwin7.bat
Add2GACxp.bat
Run the appropriate .bat file. Under Win7 you have to run this file as Administrator.
Documentation
The next link is not a real user guide but provides the basic information to use the program : LesvePhotometry User guide
You will also find interesting information in the FAQ page : FAQ
Download
Click the following links to download the LesvePhotometry setup program :
LesvePhotometry 1.2.0.32 Setup.exe
dated February 1st , 2013
- Pointing error is reported on main window, Excel and csv reports. Pointing error is the difference
between the center image coordinates given in the FITS header and the same coordinates calculted by PinPoint.
LesvePhotometry 1.2.0.31 Setup.exe
dated January 30th , 2013
- Bug correction in previous Reinsh version
LesvePhotometry 1.2.0.30 Setup.exe
dated January 27th , 2013
- Bug correction in Reinsh program : no more problems when running more
than one instance of Reinsch program at the same time
LesvePhotometry 1.2.0.29 Setup.exe
dated January 17th , 2013
If you are upgrading from version 1.2.0.15 (April 17th, 2012)
- SAVE YOUR VARIABLE AND COMPARISON STAR DATABASE before running this version.
New fields will be added automatically to your database. This process should be done smoothly
but save your database to prevent problems.
New feature :
FullWidthHalfMaximum (arcsec) is given in Excel and Csv reports. This value is derived from PinPoint engine.
The FWHM is measured by doing individual Gaussian PSF fits to the 20 brightest unsaturated stars in the plate.
LesvePhotometry 1.2.0.28 Setup.exe
dated January 12th , 2013
If you are upgrading from version 1.2.0.15 (April 17th, 2012)
- SAVE YOUR VARIABLE AND COMPARISON STAR DATABASE before running this version.
New fields will be added automatically to your database. This process should be done smoothly
but save your database to prevent problems.
New features for batch processing:
- delimiter character in file name is either "#" ,"-" or "%", user selectable in
"General Settings" tab
- if you select more than one star for the batch, separate CBA, aavso, excel and
csv reports will be created for each star and also the ReinschSpline windows.
A new option to cope with very faint Variable star (see FAQ)
The FAQ page include new topics.
New ReinschSpline.exe version 1.2.0.6
LesvePhotometry 1.2.0.22 Setup.exe
dated December 9th , 2012
If you are upgrading from version 1.2.0.15 (April 17th, 2012)
- SAVE YOUR VARIABLE AND COMPARISON STAR DATABASE before running this version.
New fields will be added automatically to your database. This process should be done smoothly
but save your database to prevent problems.
- Sloan filters are now supported.
- The name of the last loaded configuration file is displayed in the "Online results" tab.
- ReinschSpline.exe version 1.2.0.6
The Maximum/Minimum uncertainties are shown with a box on the plotting form
New with this version
- Another algorithm is used to calculate the Background annulus median. Now the program
is running 5 to 10 times faster!!
- Correction for small annulus. With previous versions, small annulus generated errors because
no pixels remained for the background calculations
- In "Photometry parameters" tab, you can choose the way the background level is calculated :
Median (recommended), Mean, (MeanMedian not yet implemented).
Detected stars in the Background Annulus are normally discarded during the background
level calculations, but you have the option to disable this function.
- The statistics of the Background Annulus are displayed in real time, including the histogram.
- The sky image is displayed with the Variable and comparison stars apertures.
The apertures are drawn with different colors, see the legend above the sky image.
Two sliders are available to control the image brightness and contrast.
To disable the sky image generation use the check box "Display sky image", it is located just above the "Go" button
- A csv report can be generated instead of an Excel file (useful for OpenOffice users).
- Sanity checks on RA, Dec, Magnitudes and "Usage" fields are performed before saving new data in the database.
- Checks are performed before deleting a comparison star in the database
LesvePhotometry 1.2.0.19 Setup.exe
dated November 25th, 2012
- Save your Variable and Comparison Star database before running this version. New fields will be added automatically to your database.
- Sloan filters are now supported.
- The name of the last loaded configuration file is displayed in the "Online results" tab.
- ReinschSpline.exe version 1.2.0.6
The Maximum/Minimum uncertainties are shown with a box on the plotting form
LesvePhotometry 1.2.0.15 Setup.exe
dated April 17th, 2012
- AAVSO report has been modified to be conform to the AAVSO Extended Format.
Now the magnitudes of C and K stars are instrumental values. The explanations are provided in this message:
http://tech.groups.yahoo.com/group/lesvephotometry/message/26
- AAVSO report field "NOTES" provides the Standard magnitudes used for the C and K stars
- The other reports are unchanged.
- ReinschSpline.exe version 1.2.0.5
When ReinschSpline.exe is used as a standalone program, the button "Save File" opens a Directory selection window and creates a file named Extremum.txt
LesvePhotometry 1.2.0.14 Setup.exe
dated March 21th, 2012
- Cosmetic updates to improve the user interface.
- Execution time for Excel report has been reduced.
- Color transformation and calculation of transformation coefficients.
- Save and load configuration. This feature is useful when you work on images created with different telescopes or cameras.
- In File menu, the "Export (entire database)" and "Settings" options have been disabled.
In the past I had introduced them to import / export data from an Access
database used in a preliminary version.
This old version has no more users.
The new features are described in the LesvePhotometry User guide
LesvePhotometry 1.2.0.12 Setup.exe
dated March 10th, 2012
- A bug in the Exposure Time has been fixed, the deprecated EXPTIME keyword in Fits header was not taken into account.
LesvePhotometry 1.2.0.10 Setup.exe
dated December 18th, 2011
- A bug in the Flatness calculation has been fixed. The algorithm failed with some star profiles.
The flatness is calculated at a threshold. It was set at 1/4 of the maximum pixel value.
Now the threshold is set to 1/3, the flatness will be less sensitive to star profile skirt.
- A tool named FitsUpdater is now available, with this tool you can modify or delete some keywords included in FITS header of star image series
The program is located in the installation directory (see above).
LesvePhotometry 1.2.0.9 Setup.exe
dated December 2d, 2011
- A bug in version 1.2.0.8 has been fixed, 1.2.0.8 is removed.
- The "Limiting Magnitude" is now calculated.
If a star is so faint that the astrometry program does not detect it,
the program will not evaluate its magnitude. The program will calculate the Limiting Magnitude and
you could report that the star is "Fainter than" this limiting magnitude.
The Limiting Magnitude of a sky image is the magnitude of a star with a SNR = 3.
The AAVSO has provided (http://www.aavso.org/ccd-views-315) a formula to calculate the Limiting Magnitude:
M_limiting = M + 2.5 * log10 (SNR/3).
where M = Magnitude of a faint star and SNR is the SNR of the same faint star.
If PinPoint (astrometry) doesn't solve the plate or if the reference star or the first check star is not detected,
the program will not generate a data result.
The error file will contains the name of the sky image and the name of the undetected Variable star.
But if the plate is solved and reference star and the first check star are detected,
the program is able to calculate the Limiting Magnitude.
The LesvePhotometry program will not report directly that the variable star is "Fainter than",
it will give the Limiting Magnitude.
In Excel report, an undetected variable star will generate a magnitude = "NaN" (Not a Number).
This report will not say that the variable star is "fainter than".
There are multiple sources for the non detection of a star : PinPoint detection parameters, cosmic ray, satellite trail, wrong coordinates, a.s.o.
The observer has to decide himself in a post-processing decision, if he reports the "Fainter than" observation or not.
The AAVSO and CBA reports will provide no data of an undetected variable star.
Notice that AAVSO and CBA reports don't already include result data if they are suspect : the SNR is too weak, a star is saturating, a.s.o.
LesvePhotometry 1.2.0.7 Setup.exe
dated November 20th, 2011
- The astrometry engine can also use USNO-B-1 (80G)
and UCAC3 (8G)
catalogs. The dc3.com PinPoint version 5.1 is needed to work with the UCAC3 catalog
- A bug in Airmass calculation has been fixed
LesvePhotometry 1.2.0.6 Setup.exe
dated November 2d, 2011
- The flux calculations are performed only with integers, the photometry execution time has been reduced by 20%
- In previous versions, you had only the option to export or to import the entire database. Now it is possible to
export (import) data of selected Variable star and its comparison stars to (from) a text file,
for details see paragraph "Database maintenance" in LesvePhotometry Tips
An example of the exported text file is given here StarExport example.txt
- Extrema results (Magnitude at extremum, associated error, Time of extremum and associated error)
are save either to the Clipboard or to a file. "Reinsch Spline" window has two new buttons to select the saving option.
Clipboard content can be pasted directly in an Excel file. When Reinsch Spline algorithm is called
from Lesve photometry, the extremum data are saved in a file located in the same directory
as the images and other reports.
- In the "General Settings" panel, you can select the output reports (Excel, CBA, AAVSO and Reinsch)
LesvePhotometry 1.2.0.5 Setup.exe
dated March 20th 2011
-The program has been corrected to take account of check box Saturation
-BZERO, BSCALE and PEDESTAL keywords has been added in the "Default settings" tab.
Indeed a user had problems with Nebulosity program which does not provide needed information in the FITS header
-The program verifies that the generated file names for reports are correct.
These names are based on the AAVSOVarName field, for details see LesvePhotometry Tips
LesvePhotometry 1.2.0.4 Setup.exe
dated March 7th 2011
The "Saturation level" is now saved in profile.
The program has been corrected to take account of Saturation level
EGAIN keyword has been added in the "Default settings"
LesvePhotometry 1.2.0.3 Setup.exe
dated December 20th 2010
In ReinschSpline, it's now possible to work only on the light curve comprised
between the Left and Right limits. Click on the new button "Keep only center data"
To get again the full light curve, click on "ReadClipboard".
LesvePhotometry 1.2.0.2 Setup.exe
dated December 8th 2010
PeriodicVSOplanner
This program help you in the observation planning of your periodic variable stars,
it calculates on night basis the stars having their maxima or minima.
In an Excel file you specify the list of your stars (name, maximum/minimum epoch, period,
Right Ascension and Declination).
For each nights, it selects the stars having a maximum and provides the Time of Maximum,
Azimuth, Elevation, Sun and Moon Distances, a.s.o
The planning results are presented in another Sheet of the same Excel file.
At a glance, you have the selection of interesting stars for a night and the needed information
to plan your observation night.
PeriodicVSOplanner.xls
which contains two sheets
StarList
--------
contains examples of RR Lyrae stars. For each star you have to introduce
Maxima/Minima epoch (in Julian Days),
Period (in days),
RightAcension (Ra in hours)
and Declination (De in degrees).
You have also to update the "Site coordinates" for you location.
You must preserve the column layout inside the green box,
but you can add rows and columns outside the this box.
You can also insert new lines in the green box for additional stars.
The program will search for the cell containing the word "VariableName"
to locate the box. So don't use the word "VariableName" in other cells.
The program stops when it reach a blank star field.
Planning
--------
will contain the results of the observation planner.
Horizon.xls
Horizon.xls file contains definition of your horizon.
Column A contains 360 cells with horizon elevation. One cell per Azimuth degree (1 to 360).
Don't forget to update this Horizon.xls file to your environment. My horizon has been used as
the default horizon.
These two files, saved in, "My Documents\DPP Lesve" will not be modified when
you reinstall the program or install a new version. They will not be erased
during program uninstallation.
Download
PeriodicVSOplanner 1.2.0.4 Setup.exe
dated December 1st 2011
- In previous versions, the "Star rise UT" and "Star set UT" were calculated for an altitude defined in the main form.
Now these values are calculated from your local horizon
(defined in the "Horizon.xls" file) and the "Minimum Star Altitude (Rise/Set)".
This minimum star altitude is very convenient if you have a very low local horizon and nevertheless you don't intend
to observe a star below this minimum altitude.
PeriodicVSOplanner 1.2.0.3 Setup.exe
dated November 2d 2011
- You have to observe a minimum of time (e.g. 1 hour) before and after the Maximum to cover correctly the Maximum.
Now you can define this time in the main form. The program will calculate the Start and Stop
observation times in JD and the corresponding Altitude and Azimuth at those times.
If at the Start or Stop observation times, the star is below your custom horizon
the Start of Stop observation times will be displayed in red.
PeriodicVSOplanner 1.2.0.2 Setup.exe
dated December 8th 2010