Votare

Hungarian

 

 

The Application Pleione 1.0

 

Introduction

 

I have been making astronomical observations since 1984. I mainly make visual observations of variable stars.

I was a student at the University of Oradea, Computer Science department between 2007-2011. This was my second university degree. I spent almost all my free time studying besides work and family. I made less astronomical observations but it was my decision.

The last year we had to select theme of thesis. As we got a free hand in this regard I could choose what I wanted to do (of course, with the approval of tutor teacher). I decided to implement n astronomy software.

I tried to satisfy one of my old desire: an application that facilitates the (visual) observation of variable stars.

Back when the AAVSO charts could not be generated at will, it happened that some stars had only one chart (e.g. d scale chart) on which there weren’t any stars could be seen with naked eye. In that case a star chart had to be taken and find the sky area corresponding using the variable star coordinates. Afterwards the observations could be made.

So I wanted to make an application which is able to generate a finder chart for a given variable star (like a planetarium software) and is able to show the observing chart with comparision stars (e.g. AAVSO-chart -- just like an image viewer software), allows the result recording of observations and finally allows to generate reports.

The following input data are required:

- the geographical coordinates of observer’s location

- local time

- date

- the list of variable stars intended to observe (generally, the list of celestial objects).

Additionaly we need a variable star catalog and a star catalog.

In the first step the program reads the data from the variable star catalog (GCVS) for each variables included in the list identifying by their names. Then it determines which variables can be seen ( above the horizon actually) by using the geographical coordinates, date and time. These variable stars are sorted by a given criterion, and this list will be displayed on the screen. The observer selects a star from the list and the corresponding finder chart and / or observing chart will be displayed.

The finder chart is generated at first and then it is plotted on screen. To do this, the Tycho catalog and the Yale Bright Star catalog are used – for representing the stars the former, the latter for writing the Bayer and Flamsteed designation of star. The finder chart’s field of view can vary between 25, 15, 9, 5, 3, 2 and 1 degree. The orientation can have two mode/ types: the top of the chart pointing north or towards the zenith. We can choose between four projection modes: stereographic, orthographic, gnomonic and equidistant.

The observation chart is displayed. This requires that the observer must have this chart of that variable previously downloaded and correctly named.

After the observation the software can record the observation and clear the variable from the list appeared on screen – if you desire.

 

IT Characteristics Of Pleione 1.0

 

The program runs under Windows operating system.

The source code was written in C # language using Microsoft .NET Framework and Microsoft Visual Studio 2008 development system.

 

The software’s block diagram is shown in Fig.1

 

Block Diagram

 

Figure 1. The application’s block diagram

 

Installation And Directory Structure Of Pleione 1.0

 

The Pleione 1.0 installer can be downloaded from here. Run the Setup.exe.

At the beginning the .NET framework will be installed (or updated if necessary) in case it is not already installed on your PC, or it will be updated.

The setup.exe will create the required directory structure including the appropriate data files. The created subfolders (AAVSO_Charts, Catalogues, Observer, Reports) can be found below  c:\Program Files\PikeSoft\Pleione 1.0\ folder – if you did not select another path during installation.

The Pleione 1.0 folder contains the following files:

- config.ini - the Pleione 1.0 reads the configuration parameters from this file at startup.

- empty.jpg - a black image;

- list.dat – the list of the observer;

- observations.dat – the recorded observations;

- Pleione.exe - the executable program;

- Pleione.ico - the programs icon;

- Pleione_Help.chm - help;

- valnam.txt – Harvard-designation of variables.

It is important that after the installation, in the observations.dat file in the # OBSCODE = ... line, the ... should be changed to observer’s code because this code will appear in all generated Reports.

In the AAVSO_Charts directory the observation charts should be stored that have been downloaded previously from e.g. the AAVSO website (http://www.aavso.org/vsp). Once installed, here we find only seven charts, from 2 star - by way of example. The charts should be named using the following rule: [STARNAME]_[ABCDEF][NS][WE][AGN][HP]  the star’s name and the chart scale, then the orientation of the horizontal and vertical direction, the variables included in the chart, at last the resolution – obviously the parameters from the AAVSO website.

The images should be saved in png format (the default format in the AAVSO website).

For example: BU_TAU_BNWAH.png.

It means the chart of BU Tau variable star. In the star’s name and after it we have to use the _ character instead of space.

The B scale of the chart (it may be A, B , C , D , E or F ).

The N means that up is North, the vertical orientation (it can be S - South is up).

The W is the horizontal orientation, West is on the right side (it can be E - East is to the right).

A refers to the variables shown in the chart: A - all variables (GCVS, NSV, etc), G - only the variables in the GCVS, N - no other variables are shown.

The H refers to the resolution of the chart: H - html resolution for screen, P - printable resolution, for printer. The latter is a higher resolution.

The Catalogues folder  contains two catalogs initially: the GCVS catalog iii.dat and the Yale Bright Star Catalogue bsc5.dat’. I downloaded the former from the http://www.sai.msu.su/gcvs/gcvs/iii/ site, the latter from the
http://tdc-www.harvard.edu/catalogs/bsc5.html site.

Because the Tycho catalog is too large (105 MB compressed), it is not installed automatically. It need to be downloaded from the ftp://cdsac.u-strasbg.fr/pub/cats/I%2F239/ page (tyc_main.dat.gz file), extract and copy (or move) in  the Catalogues directory with ’tyc_main.datname.

The Observer directory contains two files as well: the observer.dat which contains details of the observations, and the instruments.dat, which contains data from the telescopes. After the installation, these files contain the data of observer and the data of observer’s instruments. These should be modified during the first run to the appropriate user data.

The Reports folder will contain the reports created by the users in runtime, in AAVSO format. After the installation we find an example report in this directory (CSMNOV2011.visual.aavso).

The installer creates also a Pleione 1.0 shortcut on Desktop and a Pleione 1.0 folder in the Start menu.

 

Using The Pleione 1.0

 

When the user clicks on the Pleione 1.0 icon, a message box with the number of variables found in the list.dat file will be displayed. It should be noted that the variable names must be given, as listed in the GCVS. More information can be found in the Help.

After pressing the OK button the message box will be replaced by the welcome screen. The progress bar has to run alongside at three times that indicates the program in three different states. When this is done, the welcome screen will be closed and will be displayed the main GUI window.

The main window consists of two major elements: the list of observable variable stars and a chart area (Fig. 2).

 

pleione_main1

 

Figure 2. The main graphic user interface of Pleione 1.0

 

Above the list we can read the number of variables in the list and its refreshing period. This list is refreshed automatically unless the clock is stopped. The clock takes the system time and date of user’s computer. By turning off the clock, a list for any  date and time can be created.

Some more data are displayed below the list:  geographical coordinates, time zone, local date and time for which the list was made. Around here we can see the local universal time (UT) and local sideral time, there were calculated for the same aforementioned data (location, time zone, date and time).

Additionally we can see the current moon phase, its rising transiting and setting time and the times for civil, nautical and astronomical twilights. The latter dates are approximate only as the geocentric equatorial coordinates of the centers of the Moon and the Sun are calculated for the given date and time, and these times were determined based on these coordinates.

In the list we find all of the visible variable stars from the observer’s list that altitude is greater than the Invisible horizon parameter (see below) and that are intended to observe. The list is sorted in ascending order of duration. The duration means the time interval between the current date and time (for which the list was made), and the setting time of the star. In case of circumpolar stars, the time of lower culmination is used instead of seting time. If the star is not visible (below the horizon), it is not listed.

A star is deleted from the list:

- when the user records an observation of it (and the Clear variable star from list chekbox is chekeded;

- or by double-clicking on the first coloumn of variable’s line, which is containing the word True).

If you select a star from the list, you can see it’s finder chart. To do this, you need to press one of File Of View button near Finder Chart button. The chart is generated, for which the Tycho and the Yale Bright Star Catalogue are used - this should take a few seconds - and then it will be displayed. The field of view of finder chart can be changed by pressing another Filed Of View button or by using the Zoom Out / Zoom In buttons. When you press e.g. the 15 degrees button, the 15 degrees finder chart will be generated and displayed. Then, if we decrease the field of view, the new chart will appear quickly as no new chart is generated. But if we increase the field of view (by pressing the 25 degrees or the Zoom Out button), the new chart will be generated and displayed.

The chart’s orientation can be adjusted by the N and Z keys.

The magnitude limit can be changed by the Mag. limit buttons (+ and - buttons).

On the chart the Bayer and Flamsteed designations of stars are shown  too. This can be activated/disactivated by the Flamsteed ON / OFF button.

The finder chart’s parameters (the size of field of view, orientation, projection mode, magnitude limit) can be read above the chart area.

The main window has two display modes: day and night (Fig. 3). One of these can be selected by pressing the Night View On / Off.

 

pleione_main2

 

Figure 3. The Pleione 1.0 in night mode

 

If you select a variable, a list of available AAVSO charts will appear – that are located in the AAVSO_Charts folder. If there is a chart with parameters you set with AAVSO chart radio buttons, the list will contain only this chart and it can be seen immediately in the chart area. Otherwise the list will contain all charts of the star. If you select one of them, it will be displayedit in chart area. Here the Zoom Out and Zoom In buttons can be used as well (Figure 4).

 

pleione_main3

 

Figure 4. The AAVSO chart

 

At the first usage of a chart  before appearing the night view of the chart is created. It takes a few seconds (Fig. 5).

 

pleione_main4

 

Figure 5. The night mode of AAVSO chart

 

Switching between the finder chart and the observing chart is helped by Finder Chart and AAVSO Chart buttons.

Another way to select variable is introducing its name in the text box above the chart. This is useful if the list is long and it is not necessary to find the star, or if the star was deleted from the list.

If the user observes the variable star, it is possible to record the measurements. By pressing the Observation Recording the Observation Recorder window will appear.

 

Recording The Observations

 

The Observation Recorder window is shown on the Fig. 6.

 

observation_recorder

 

Figure 6. The Observation Recorder window

 

In this window some input data are already filled, like the current date, time and the name of selected variable star. Of course everything can be changed. The magnitude value has to be inserted without decimal separator (dot ’.’ or comma ’,’). For negative ("fainter than") observations use the < sign. For marking uncertain observations the colon sign or ’Z’ AAVSO comment code can be used. The program automatically converts the former to the latter.

By pressing Add button the observation will appear on the bottom of the window. This is only temporarily stored. The observation could be modified (Modify button) or deleted (Delete button). It will be permanently stored without closing the window by pressing the Close button, or recording further observation.

The variable name can be entered either in lowercase or uppercase or mixed. By checkingthe Make UPPERCASE variable star name chekbox (the default), the variable name becomes uppercase automatically. Otherwise it remains unchanged.

Another setting is: keeping or deleting the variable’s name in the textbox. This may be useful if more observations of the same variable are entered – e.g. you introduce data from your observations diary.

In case of closing the Observation Recorder window the selected (observed) variable star will be removed from the list. If you do not want this, turn off the "Clear variable star name from list option by uncheking this chekbox.

Other kind of other observation data can be entered as well, like AAVSOs commentcodes, values of comparisions stars, chart id, notes.

The observations are stored in the observation.dat files.

 

The Configuration Options Of Pleione 1.0

 

In the File menu the paths of folders and files can be set, or you can choose other files to use (e.g. if you save catalogues with another name or a the observer’s list has a different name).

The Observer menu is used for setting the observer’s data: personal information (name, observer’s code, address, etc), geographical data of observing location, and the data of observing instruments. For the proper functioning of the program it is essential to set the latitude and longitude, time zone and daylight saving  time. Also here the Invisible horizon parameter can be set. This parameter is the minimum altitude of objects, for which we can make observations. This parameter can vary due to e.g  the transparency of atmosphere. The software filters out non-visible stars from the observing list based on the value of Invisible horizon. If an object’s altitude is less than this value, it will not be added to the list of visible stars.

The projection mode of finder charts (stereographic, orthographic, projection gnomonikus and distant representation) also can be selected in the Projection menu.

In the Display menu settings for the display can be found. Here the night mode can be turned on / off (by clicking on Night View item, just like clicking on the Night View On / Off button in the main window). In the same way displaying the Bayer and Flamsteed designation of the stars on the finder chart can be turned on/off, as already mentioned in connection with the Flamsteed ON / OFF button.

The list’s refreshing period can be set by clicking on the Refreshing Period item. This list is updated only when the clock is turned on.

The finder chart has seven different colors, but this valid only for daily display mode:

  1. sky color (black by default)
  2. stars color (white by default)
  3. stars Bayer and Flamsteed name color (yellow by default)
  4. selected variable star color (red by default)
  5. selected variable star name color (red by default)
  6. other variable stars’ color (pink by default)
  7. other variable stars name color (pink by default)

In night mode the sky is black everything else is red.

The shape of star objects can be chosen abomgst five different forms. This option is suitable only for the finder chart.

If you do not want a message for each deleting of a star from the list, you need to turn off this option clicking on the Deleting Message item.

 

Reports and More

 

Reports of observations can be created by clicking on Make Report menu item. The report can be either a monthly or a nightly report. In the report the stars are sorted by their name or by their Harvard designations. In case of monthly reports, the report will be saved in a file named cccmmmyyyy.visual.aavso located in the Reports folder, where ccc is the observers code, mmm is the month while yyyy represents the year. The nightly report is saved in a file named cccyyyymmdd.visual.aavso. Of course ccc is the observers code, yyyy is the year, mm is the month and dd means the day.

Displaying the observations also can be done by the Viewing Observations menu item - only the desired period of time need to be specified. It is possible to filter the observations of one given variable star.

’Statistics’ menu item is dedicated for displaying statistical data. By selecting a time range, the number of observations/observed stars/’Fainter than’/inner sanctum observations can be displayed within that period. An inner sanctum is a positive observation of magnitude 13.8 or fainter, or a fainter-than observation of fainter than 14.0 or fainter.

 

Acknowledgments

 

I would like to thank Sándor Hadházi, Judit Hannák, Tamás Jakabfi, István Kovács, Miklós Magyari, András Sajtz and György Soponyai for helping me creating and testing the software.

 

Closing Remarks

 

I encourage everyone to use the application. Please send your comments, bug reports to the csukas.matyas@gmail.com e-mail address.

Clear skies!

 

Mátyás Csukás