Sky Charts 

Menu Commands

All the commands can be used from the main menu or the tool-bars.
It is possible to move each button group where you want and select which group to display using the View->Tool-bar option from the main menu. You can hide the main menu to free some space on the screen. Use the Space or Esc key to show the menu again.

The tool-bar icons correspond to the main menu functions.


  Save or reload a chart previously saved to a file.

  List of all objects in the active window. You have the option of searching for an object in the list, to sort the objects by Right Ascension, to print the list or to save it to a file. You can create a catalog file for use with "Astrometrica"

You can click a line in this list to show the detailed identification window.

The menu "Preference - Object list content" lets you filter the object type to show in the list:

  This menu gets you directly to the Internet resources .

- Images from different catalogs.
- Stars from GSC and USNO-A catalogs.
- Update the elements of comets and asteroids.

NOTE - You have to be connected to the Internet before you can use this function.

Bulk calculation of asteroid positions for a given date

  Azimuth position for the location and the time in the direction of the main chart center. It is possible to change the direction of observation and the limiting magnitude. This chart is automatically updated if the main chart gets changed.

The function projection types allow to use azimuthal projection for the main chart.


  Print screen contents to a selected destination. The orientation and the colours can be selected.
It is also possible to type a title and description for the chart, to change the page margin or to not print any legend.
With "Portrait" orientation it is possible to also print the list of the object in the chart to the same sheet of paper. First check with the button to ensure the list is not too long! Use the menu "Preference" to select the object you want.

  Printer resolution and printing scale in minutes/cm


It is possible to use the internal viewer or your default browser.

  Exit the program
You are asked to select whether you want to save the current options before you exit. Select Yes if you want to start the next session at the point you stopped here. If you always respond to this question in the same manner, you can check the bottom box to avoid this prompt in the future. The menu Preference allows you to reactivate this question box.


  Copy the screen content to the clipboard, to a Windows metafile (.wmf) or to a bitmap file (.bmp, .gf or .jpg). The key "p" activates this function if the menu is disabled.

  Immediately refresh the current chart.

The right mouse button on this icon selects or deselects the automatic refresh of the current chart after every operation.


Set the step by days, hours, minutes, seconds then click one of the arrows to increment or decrement the current time. It is possible to add a delay by using the cursor or to go step by step.
The position is constant right ascension and declination in the case of equatorial coordinates or constant azimuth and altitude in the case of azimuthal coordinates.
To follow the displacement of a solar system object (planet, comet or asteroid) select it by a right mouse click and select "Track ..." from the menu.
For better animation use only necessary options and a minimum number of catalogs. It is also important to activate the "use memory cache" option.

To record the animation to an AVI or GIF file, indicate the file name, the playback frame rate, the file format and check the "Record" box. Be aware this may create a very large AVI file.

  Flip the chart horizontally.

  Flip the chart vertically.


  Zoom in twice. Same function as + key.

  Zoom out twice. Same function as - key.

  Undo last zoom. 

  Select the field of view in degrees.

This scale lets you quickly select any value between 6' and 360°. To access a smaller field of view down to 2" you can use the +/- key or the Locate panel.

You can also use a wheelmouse to zoom or the middle button of a three button mouse + the Ctrl key. These both require a recent processor (>1000Mhz) to work well.

  Change the number of stars or nebulae displayed from the current catalog. The corresponding values are updated to the Star magnitude limit and Nebula size limit parameters for the actual field of view.

  Night vision (red screen).

  Switch the stars and nebulae drawing mode. 

Switch the sky background color between the fixed color (black) and the color representing sky luminosity.

  Display the magnitude scale and the legend of all used symbols.

The following information is displayed:
Var   Variable star
Dbl   Double star
b-v   Colour index
Gx    Galaxy
Oc    Open cluster
Gc    Globular cluster
Pl    Planetary nebula
Neb   Bright nebula
N+C   Nebula and cluster
Star  Cataloged nebula identified as star
Unk   Cataloged nebula unidentified


  Move the chart in the corresponding direction. You can also use the keyboard arrows or press the middle button or wheel of the mouse.

  Change the field of view to the indicated value.

  Chart rotation  +15 degree , +45 degree if you press Ctrl, +1 degree if you press Shift.

  Chart rotation  -15 degree , -45 degree if you press Ctrl, -1 degree if you press Shift.

  Switch equatorial and azimuthal projection.

  Show all the visible sky from the current location.

  Show the zenith or North, East, South, West horizon.


  Find an object.

Find an object by name in the following catalogs: Messier, NGC, IC, GCVS, WDS, Boss GC, GSC, SAO, HD, BD+SD, CD, CPD, HR. NOTE - The corresponding catalog or index must be installed. Or use an active external catalog.
Enter the catalog number in the "Cat Id" field. For the GSC, enter region number and star number separated by space. For BD id's enter sign and declination zone number, a space, then star number ( i.e.: +36  2844 ).
To search an object by another catalog identifier like UGC, MCG, PK, ... use the option SAC for the most luminous or the option NED and SIMBAD to access the full catalog via Internet. Please consult the online documentation for specific naming when using these two options.

To find a variable star you can use a name from GCVS like "Y Cas" or "V1357 Cyg" or a suspected variable number like "NSV 1205" or an extragalactic variable name like "SMC V0220" or "N4486 V0002". You can use upper case or lower case for the name. The only exception is "U Her" and "u Her".

Find the planets, comets and asteroids.
The Comets and asteroids list contains only those selected in Catalogs Selection menu

Find by constellation name, star name (common name, Bayer, Flamsteed).
For Bayer name enter the Greek letter abbreviation first, then the constellation abbreviation (i.e.: GAM AND for Gamma Andromedae). For Flamsteed numbers enter the star number and the constellation abbreviation.

It is also possible to search for an Uranometria 2000 chart number.

You can do a quick search without opening the main search window by using this box:
In this case you must type the catalog name prefix and catalog number, then press Enter to do the search.
Here are some examples of valid queries: m8, M 8, ngc7331, ic 434, SS cyg, tyc1800 1718, ugc 7517, STF2382, rho oph, 51 peg, pk 29-5.1, mars, ...

  Quick locate on the constellation chart. Click a position on the chart to locate it. Use the + - button to zoom on this chart.

  Locate by entering the coordinates and the orientation.


  Catalog selection and their visibility

  Setting time and date

  Setting the location of the observation

  Configure the colors and the appearance of the stars and objects

  Projections type

  Labels of the selected objects


- Default choice for the identification function. Short identification (in the status bar) or long in a popup window. The Alt key swaps this behaviour. 
When in Short mode a click to the label opens the detail window.
The "Center" button places this object at the center of the chart. The "Neighbor" button shows a list with all the objects in the vicinity.

- Fonts selection. Use the button on the right to change a font.

- Program language selection.

  Save the current configuration for the next session.

Two status line menu: You can use this option to use two lines to display the status information. This permits showing the full information for some objects, but also gives more information about the cursor position.

Moving the cursor:
This shows both equatorial and azimuthal coordinates for any projection setting.

After you click on two objects this shows the distance between the two objects, the position angle, and the difference in position in right ascension and in declination.


  Display the equatorial coordinates grid. Right click on grid icon to change the grid spacing.

  Display the azimuthal coordinates grid. (only when displaying azimuthal coordinates)

  Display the coordinate grid values.

  Show eyepieces or CCD camera field at chart center. It is also possible to place a circle anywhere on the chart using the right mouse button. This figure is also used to show the telescope position.
Click with the right mouse button on this icon to configure the eyepieces :

The selection "Eyepiece" lets you choose the appearance of the circle corresponding to the field of view of your eyepiece. It is possible to draw up to ten different eyepieces. Enter the size of the field of view in minutes of arc and the associate label. If you want to know the field of view of your eyepiece, divide the apparent field of view by the magnification. i.e. an eyepiece with a focal length of 20 mm and an apparent field of view of 40° used on a telescope with a focal length of 2000 mm: 
Magnification = 2000 / 20 = 100
Viewing field = 40 / 100 = 0.4°
Viewing field = 0.4 * 60 = 24 minutes
The value of 24 is the answer to the question.

  Draw the constellations figures.

  Draw the constellations boundaries.

More options available only from the main menu:
- Local Horizon : Plot the local horizon from a file containing azimuth and local horizon altitude.
- Ecliptic line.
- Galactic equator line.
- An option to draw a line to connect the position of the planets, comets, asteroids at different dates.
- Milky Way.
- Uranometria 2000 charts boundaries: Plot the chart of this atlas.


  Display an image from the Realsky® or DSS CD's on the current chart. The field of vision must be less than 7 degrees. If configured the plate list will display.

Look at exposure time and margin to help choose the best plate. The margin is positive if the chart is entirely contained in the plate or negative if a truncation occurs at the plate border.

   Sky image. It is possible to overlap an image on the corresponding sky chart. To adjust the chart and the image, you need to first identify an object on the chart (left mouse button) and then locate the corresponding position on the image (Ctrl+left mouse button). Repeat the same operation with another object. The right mouse button on this icon presents a menu to remove the image from the chart.

  Remove the image from the chart.

  Make the image and the chart blink alternately. 
The right mouse button lets you change the blinking speed.


These are the commands that control a telescope from the program. They are available from the button bar, the menu bar or with a right click of the mouse.

Menu Telescope - Select Scope Interface: Select the interface type you want to use. Only correctly installed optional plugin are displayed.
The following models are actually supported:
Plugin Encoder: encoder based on Tangent system, Ouranos, NGC-Max, etc...
Plugin Meade: Meade telescope LX200, ETX, LX90, Magellan or compatible models.
Plugin ASCOM: Any telescope supported by the ASCOM platform including most Celestron models.

 Open the interface screen to configure and connect the telescope.

 Move the chart center to the current telescope position.

 Permanently follow the telescope position.

 This button is active only after you select an object on the chart. If you use an LX200, the telescope coordinates are reset to those of the current object. If you use the encoder, the current object is added to the initialisation list, this also works for initial alignment.

 This button is active only if your telescope accepts the seek order and if you select an object on the chart. This moves the telescope to the selected object.

The right mouse click offers one more option: "Goto Cursor Position" which you can use to move the telescope to any location even if there is no object there.

Mouse functions:

  • The cursor coordinates are displayed at bottom-left corner of the screen
  • Shift + Move: Continuously identify the objects in the pointer. 
  Left button:
  • Simple click: Identification of an object and its distance from the previous pointed object
  • Alt + simple click: Swap the default identification function (popup or status bar)
  • Shift + simple click: Identification of the objects in the circular pointer.
  • Shift + Move: Move the chart, same as middle button.(*)
  • Click + movement: Definition of the zoom window.
  • Click + movement in the zoom window: Move the zoom window.
  • Simple click in the zoom window: Zoom
  • Ctrl + simple click: Mark objects position on the picture
  Right button:
  • Simple click: Display a menu with following functions:
    • The sky chart is centered where the cursor is located.
    • Identify the objects near the cursor position.
    • Place a finder circle at cursor position. You can move the circle and then use the left button to fix it.
    • Remove the last entered finder circle.
    • Remove all finder circles.
    • Add a free label.
    • Remove the last label.
    • Remove all labels.
    • Identify the planet, comet or asteroid to follow during animation.
    • Sync and Goto telescope command.

 Middle button:

  • Click + movement: Move the current window (*).
  • Ctrl + vertical movement: Zoom (*).

 Mouse wheel:

  • Click + movement: Move the current window (*).
  • Rotate: Zoom (*).

(*): This functions require a recent processor (>1000Mhz) to work well.

Keyboard shortcut:
1 10 minutes field of view
2 1 degree field of view
3 5 degree field of view
4 15 degree field of view
5 30 degree field of view
6 50 degree field of view
7 90 degree field of view
8 120 degree field of view
9 200 degree field of view
a   Show all the visible sky from the current location.
c Catalog selection and their visibility 
e Show East horizon
f Find an object 
h Azimuth position for the location and the time
l Labels of the selected objects
m   Locate by entering the coordinates and the orientation.
n Show North horizon
p Copy the screen content to the clipboard or a file 
q   Switch equatorial and azimuthal projection.
r   Chart rotation  +15 degree
R   Chart rotation  -15 degree
s Show South horizon
t Setting time and date 
w Show West horizon
z Show the zenith
+ Zoom in twice
- Zoom out twice 
Keyboard arrow  move the chart to the corresponding direction.
Enter: Hide or show the tool-bars.
Space or Esc Hide or show the main menu.
Shift Slow down the zooming and movement
Ctrl Speed up the zooming and movement

Command line parameters:

Ciel.exe command will accept the following parameters:
(always use a space between the parameters and their value)

-ar hh.hhhh Initial right ascension in decimal hour
-de dd.ddd Initial declination in decimal degree 
-w dd.dd Field of view in decimal degree
-c nnn.cdc Load the saved chart nnn.cdc 
"CAT: catid
ID: nnn"
Find object nnn in catalog catid 
then center the chart at this position
Don't use along with -ar or -de 
-o "LAT:+00d00m00.0s
OBS: nom obs"
Set the observatory location
-d yyyy-mm-ddThh:mm:ss Set date and time
-dss "CDdrive ImagePath 
ImageName reuse"
Extract a RealSky image corresponding to the initial chart
Set reuse to 1 to use an existing image file instead of reextracting the image.
-i  Run iconized.
-t Trace the execution to the file trace.txt
-p 1

Write a file ciel.pos containing the position of the currently selected object.
This file is refreshed each time it is deleted by the application that reads it. The refresh delay after the delete is indicated in parameter, the default value is 1 second. The file ciel.pos contain the following values:
line 1 = Date and time (current time + 1 second)
line 2 = RA decimal hours
line 3= DEC decimal degrees
line 4= AZ decimal degrees
line 5= ALT decimal degrees
line 6= Object name

DDE Interface:

It is possible to obtain information about the current chart or to give command to the program using a DDE interface.

Run ciel.exe then insert the following field in a MS Word document:
{DDEAUTO ciel DdeSkyChart DdeData}

The field is replaced by the value from the current chart and is automaticaly updated as the chart changes. 
The values returned by line:
line 1: Data update time
line 2: Chart center coordinates and field of vision
line 3: Status bar value, last object identification
line 4: Time of the chart
line 5: Observing place

27.11.1999 12:06:07
RA:  0h42m42.00s DEC:+41°16'00.0" FOV:+78°00'00"
  0h42m44.40s +41°16'08.0"  Gx PGC 2557   NGC   224      .SAS3.. D:190.5/61.7' mB: 4.36 b-v:0.92 mB/'2:14.37 RV:  -121
LAT:+46d13m00sLON:-06d09m00s ALT:375m OBS:Geneve

Use DDE Poke function to send command to the program. Only one command can be sent at a time.
The following commands are available:

MOVE RA: 00h00m00.00s DEC:+00°00'00.0"
chart center and field of vision
FIND CAT: catid  ID: nnnn search an object
DATE yyyy-mm-ddThh:mm:ss observation date
OBSL LAT:+00d00m00.0s LON:+00d00m00.0s
000mOBS: nom obs.
observation location
PDSS CDdrive ImagePath ImageName reuse DSS cdrom parameters
SBMP ImageName save as.bmp
SGIF ImageName save as .gif
SJPG ImageName Quality (0..100) save as .jpg
IDXY X: pixelx Y: pixely identify object at position pixelx pixely
GOXY X: pixelx Y: pixely set the chart center at position pixelx pixely
ZOM+   zoom in
ZOM-   zoom out
STA+   more stars
STA-   less stars
NEB+   more nebulae
NEB-   less nebulae
GREQ   switch equatorial grid
GRAZ   switch azimuthal grid
GRNM   switch grid values
CONL   switch constellation shape
CONB   switch constellation boundaries
EQAZ   switch equatorial - azimutal projection
LOAD .cdc file name Load the saved chart
SAVE .cdc file name Save the current chart

If you are interested in using this function from a program, I suggest you download an example with Delphi source code from the source code page.
It is the responsibility of the calling program to send coherent values, otherwise results may be unpredictable.