Variable Stars Observer

VarObs version 3.0 beta

June 22 2008
by Patrick Chevalley
http://www.ap-i.net/skychart

This program help you to plan and log variable stars observations.

The main windows show for each star in the current input file the time of next minima and maxima and the estimated actual magnitude.
Each column can be sorted by clicking the corresponding heading.
A mouse right click on a line show you a menu to enter a new observation, to show the estimated light curve and your observation point or to plot a chart.

Options :

Use the File - Options menu to define :

1- The data file used by the program to plot the light curve. The default option is to work with file in AAVSO Visual format but you can also read VSNET, AFOEV or other old AAVSO files or define your own file format to plot observation.
It is possible to plot data from the AAVSO Quick Look or AFOEV Archive without checking this option here, look forward at the Light Curve plot.

2- Select to use either the internal data entry or the AAVSO PCObs program to record your observation. Using PCObs is recommended if you submit your observation to the AAVSO.
If using the internal tool specify the observation file where you store the data you enter from the program. This file can only be in AAVSO Visual or in VSNET format.
The normal way to use this program is to use the same file to plot light curve and to log observation, this can be the cumulative file generated by PCObs.

3- The default observer name initials.

4- The default saved chart used to initialize "Cartes du Ciel / Sky Charts". This allow you to use different chart default when running ciel.exe from varobs (typically use a smaller window and activate the GCVS catalogue).

5- The source of the additional observational data to plot. You have the choice between the AAVSO Quick Look and the AFOEV Archive data. This data are plotted in addition to the one specified at point 1-.
QuickLook is good to display recent observation over a short period, on the other hand AFOEV Archive give data for a long period.

6- The path the the AAVSO charts directory, this can be a local directory or Internet access. Press “...” to select the local directory or press the “Internet Online Access” button to access from the AAVSO web page, or enter ftp://ftp.aavso.org/charts/standard for FTP access.
The chart is displayed using the default application in your system, this is the default browser in the case of Internet access or the image software assigned to .gif or .jpg files.

Planning :

The initial display show observing condition for variable stars in the ephemeris file, the actual magnitude estimate is rounded to the nearest integer to avoid subliminal influence to your estimate.
Select the date format you want and press "Compute".
You can search for a star name or sort the column by a click to the heading.
A mouse right click on a line show you a menu to enter a new observation, to show the light curve, display the AAVSO chart or to plot a chart using "Cartes du Ciel / Sky Charts".
Beware to use up to date ephemeris file to obtain a good precision, specially for short period variables.
This version of the program came with data for long period variables updated with the data from the AAVSO bulletin. This is the aavsoxxx.txt files.

The Tools Menu let you refresh this data each year with the files published on the AAVSO web page.
You can also copy the stars of your observation plan from the file aavsoval.txt which contain data for the entire validation file.

You can change the active file using the File - Open menu. This allow you to use different observation list.

The file format is : star name , var. type , mag. max. , mag. min. , initial epoch , period , rise time or eclipse time, aavso designation
Each field is separated by a coma. See file sample.txt for more explanation and examples.
For the magnitude the program assume that a value without dot is given in tenth of magnitude. (15 is magnitude 1.5 but 15. is magnitude 15.0)

The files in the \const directory are ephemeris input files by constellation for 16'000 stars from the GCVS.
Beware that the origin date for this ephemeris is far from now and the precision may suffer of that. Then this files must be considered as examples only.

Light curve :

This screen show you a predicted symbolic light curve as well as observation data point. For irregular variables or if insufficient parameters are given only the observation are plotted. If the period is missing the data are show from 100 days before the actual date.
Click on the graph to view the magnitude and date. A check box give you the choice to stay on the curve or not.
You can change the colour as you want (click the colour box) or copy the graph to the clipboard or to a bitmap file.
If you are connected to the Internet it is possible to get additional data form the source specified in the Options. This can be data from the AAVSO Quick Look , VSNET data browser or AFOEV Archive. Use the "Get QuickLook" or "VSNET browser" button for that.
This data are stored in the quicklook\ , vsnetdata\ or afoevdata\ directory to use them offline later and the display is controlled by the "Plot QuickLook" or "Plot VSNET data" checkbox.

If you check "Group observation to current phase" all observation data in file are reduced to the current phase. This require a very regular and well know period value. The goal is to find the observation date favourable to complete a light curve with missing data at some phase.

Enter new observation :

If you use the internal tool :

Complete all necessary field then press the "Add" button to put the line in the list and you may enter a second observation or modify entry in the list.
Then press "Save to File" to record all observation in the list to the observation file.
Other option are to clear all the list or edit the observation file. To do that you must have a program associated with the observation file type. (if you use the default .txt this will use notepad.exe or another text editor).
If you record your observations in VSNET format the program try to automatically convert the star name between gcvs and vsnet notation ( R And -> ANDR, omi Cet -> CETomicron).
If you use the AAVSO PCObs program :

I suggest you always use this program if you intend to submit your observations to the AAVSO. It is available from http://www.aavso.org .
PCObs is started the first time you need it. The star designation if available or the star name is copied to the clipboard, you can use Shift+Insert to copy the value to PCObs.
Refer to the PCObs documentation for more information.

AAVSO Charts :

After a click to this menu a list of the available charts for the current star is presented. To display a chart just click the line with the chart you want.
You have generally the choice for an image format (GIF, JPG, PNG) or a Postscript file compressed to a ZIP file.
Refer to the AAVSO web page for more information on the different charts.
The program use the AAVSO chart database to find the available charts for a star. You may need to updated this file regularly to take advantage of new or updated charts. Download the file united.txt from http://www.aavso.org/observing/charts/chartdatabase.shtml and replace it in the installation directory.

Plot Chart :

It is necessary to install "Cartes du Ciel / Sky Charts" first. This program is freely available from http://www.astrosurf.org/astropc
The program version must be at least 2.44 for DDE server support.
Install the base package along with the variable star package. The Sky2000 Master Catalog or Tycho Catalog package is also recommended for good reference stars magnitude.
Run ciel.exe a first time to initialize default value for the program. After that the program can be started automatically from varobs the first time you select "Show Chart".
It is possible to use specific default when starting ciel.exe from varobs.
First: run ciel.exe and select all the option you want (window size and position, field of vision, catalogue used, labels or grid, ...) then use "File" -> "Save chart" and give a name to your default file.
Second: run varobs.exe and put your file name including full path in the "Setup" panel.
Use this charts only as finder charts, always use the charts from AAVSO or VSNET for reference stars magnitude.
"Cartes du Ciel / Sky Charts" can only find variables stars name in standard format (i.e. R And) but not in VSNET notation (i.e. ANDR) then use the standard format name in your ephemeris file. This is not a problem as the name is automatically converted to VSNET format in the observation file.
This option is not available if the program is started from Deepsky 2000. Run the chart from Deepsky 2000 in this case.

Command line parameter :

-c filename Specify the name of the ephemeris file to use.
-n Disable the chart menu.

License :

Copyright (C) 2008 Patrick Chevalley
pch@ap-i.net

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.