# Configuring &kstars;

## Setting the Geographic Location

Here is a screenshot of the Set Geographic Location window: Changing the Geographic Location Set Location Window

There is a list of over 3400 predefined cities available to choose from. You set your location by highlighting a city from this list. Each city is represented in the world map as a small dot, and when a city is highlighted in the list, a red crosshairs appears on its location in the map.

It is not practical to scroll through the full list of 3400 locations, looking for a specific city. To make searches easier, the list can be filtered by entering text in the boxes below the map. For example, in the screenshot, the text `A` appears in the City Filter box, while `Te` has been entered in the Province Filter box, and `USA` is in the Country Filter box. Note that all of the cities displayed in the list have city, province, and country names that begin with the entered filter strings, and that the message below the filter boxes indicates that 6 cities are matched by the filters. Also notice that the dots representing these six cities in the map have been colored white, while the unmatched cities remain gray.

The list can also be filtered by location in the map. Clicking anywhere in the world map will show only those cities within two degrees of the clicked location. At this time, you can search by name, or by location, but not both at once. In other words, when you click on the map, the name filters are ignored, and vice versa.

The longitude, latitude and time zone information for the currently-selected location are displayed in the boxes at the bottom of the window. If you feel that any of these values are inaccurate, you can modify them and press the + (Add City) button to record your custom version of the location. You can also define a completely new location by pressing the Clear Fields button, and entering the data for the new location. Note that all fields except the optional State/Province must be filled before the new location can be added to the list. &kstars; will automatically load your custom locations for all future sessions. Please note, at this point, the only way to remove a custom location is to remove the appropriate line from the file `kstars/mycities.dat` in your folder ``qtpaths` `--paths GenericDataLocation``.

If you add custom locations (or modify existing ones), please send us your `mycities.dat` file so that we can add your locations to the master list.

## Setting the Time

When &kstars; starts up, the time is set to your computer's system clock, and the &kstars; clock is running to keep up with the real time. If you want to stop the clock, select Stop Clock from the Time menu, or simply click on the Stop Clock icon in the toolbar. You can make the clock run slower or faster than normal, or even make it run backward, using the time-step spinbox in the toolbar. This spinbox has two sets of up/down buttons. The first one will step through all 83 available time steps, one by one. The second one will skip to the next higher (or lower) unit of time, which allows you to make large timestep changes more quickly.

You can set the time and date by selecting Set Time... from the Time menu, or by pressing the time icon in the toolbar. The Set Time window uses a standard &kde; Date Picker widget, coupled with a spinbox for setting the hours and minutes. If you want to re-synchronize the simulation clock back to the current CPU time, just select Set Time to Now from the Time menu.

&kstars; can accept very remote dates beyond the usual limits imposed by QDate. Currently, you can set the date between the years -100000 and +100000. We may extend this range even further in future releases. However, please be aware that the accuracy of the simulation becomes more and more degraded as more remote dates are examined. This is especially true for the positions of solar system bodies.

## The Configure &kstars; Window

The Configure &kstars; window allows you to modify a wide range of display options. You can access the window with the configure toolbar icon, or by selecting Configure &kstars;... from the Settings menu. The window is depicted below: Configure &kstars; Window Configure &kstars; Window

The Configure &kstars; window is divided into eleven pages: Catalogs, Solar System, Satellites, Supernovae, Guides, Colors, FITS, INDI, Ekos, Xplanet and Advanced.

In the Catalogs page, you determine which object catalogs are displayed in the map along with several properties.

In the Solar System page, you can specify whether the Sun, Moon, planets, comets and asteroids are displayed.

The Satellites page allows you to set the satellites view options.

The Supernovae page allows you to manage how supernovae are displayed by &kstars;.

The Guides page lets you toggle whether non-objects are displayed (&ie;, constellation lines, constellation names, the Milky Way contour).

The Colors page allows you to set the color scheme, and to define new custom color schemes.

For detailed explanation of the options on the FITS page see the Configure FITS section.

For detailed explanation of the options on the INDI page see the Configure INDI section.

For detailed explanation of Ekos astrophotography suite, see the official Ekos page.

The Xplanet page provides fine-grained control over Solar system planet surface renderer Xplanet (should be installed separately).

The Advanced page provides fine-grained control over the more subtle behaviors of &kstars;.

## Catalogs

Catalogs Window Catalogs Window

In the Catalogs page, you can configure which object catalogs are displayed by &kstars;, as well as how much information you would like to be included on the Sky Map. By default, &kstars; includes ~300,000 named and unnamed stars up to magnitude 8. For Deep Sky Objects, the included catalogs are New General Catalog (NGC), Index Catalog (IC), and Messier Catalog.

New General Catalogue of Nebulae and Clusters of Stars (abbreviated as NGC) is a catalogue of 7,840 deep-sky objects.

Index Catalogue of Nebulae and Clusters of Stars (abbreviated as IC) serves as a supplement to the NGC, and contains an additional 5,386 objects, collectively known as the IC objects.

Messier Catalogue is a catalogue of 110 deep-sky objects, including diffuse nebulae, planetary nebulae, open clusters, globular clusters and galaxies. Messier objects have names like M1, M2, up to M110. The maximum apparent visual magnitude of Messier Catalogue is represented by M91's value of 10.2.

You can install new catalogues using &kstars; Add-On Installer. You can open it by opening the Data Download New Data... submenu. You can choose from a list of catalogues, including:

- Steinicke NGC/IC Catalog: is a more complete NGC/IC catalog.

- Abell Planetary Nebulae Catalog: is a catalog of 86 planetary nebulae. The maximum magnitude is represented by Abell 47's value of 19.5.

- Sharpless HII region Catalog: is the Sharpless (Sh2) catalog of HII regions (diffuse nebulae).

- Hickson Compact Groups: is a catalog consisting of 99 compact groups of galaxies.

- Tycho-2 Star Catalog: is a catalog of more than 2.5 million of the brightest stars. It contains stars with a magnitude value from 8.0 to 12.5.

- USNO NOMAD Catalog: is a catalog of about 100 million stars with magnitude from 12.5 to 16.5. Note that is requires Tycho-2 to be installed.

The following is a summary of catalogs in KStars:

## Stars Catalogues

Name | Abbreviation | Number of objects | Magnitude | Add-On | Default
Default Catalog | Default | ~300,000 | Up to 8 magnitude | No | Yes
Tycho-2 | Tycho2 | more than 2.5 million | 8.0-12.5 | Yes | No
Naval Observatory Merged Astronomic Dataset | USNO NOMAD | 100 million | 12.5-16.5 | Yes | No

## Deep-sky objects Catalogues

Name | Abbreviation | Number of objects | Magnitude | Add-On | Default
Index Catalogue of Nebulae and Clusters of Stars | IC | 5,386 | Up to 18.3 magnitude | No | Yes
New General Catalogue of Nebulae and Clusters of Stars | NGC | 7,840 | - | No | Yes
Messier Catalogue | - | 110 | Up to 10.2 magnitude | No | Yes
Steinicke NGC/IC | - | - | - | Yes | No
Abell Planetary Nebulae Catalog | - | 86 | Up to 19.5 magnitude | Yes | No
Sharpless HII region Catalog | Sh2 | - | - | Yes | No
Hickson Compact Groups | - | 99 | - | Yes | No

The Stars section allows you to manage how stars are displayed in &kstars;. You can choose to see the stars or not by checking the Star Catalogs checkbox. If you check it, then multiple options will be enabled. Thus, you can set how many stars are drawn on the map using the Star Density slider. You can also customize &kstars; to toggle star name and magnitudes. Star names are drawn next to bright stars. To display labels of fainter stars, increase the Label density slider.

Below the stars section, the Deep-Sky Objects section controls the display of several non-stellar object catalogs. You can toggle the display of Deep Sky Objects and control the display of their names and magnitudes. By default, the list of deep-sky objects includes the Messier, NGC and IC catalogs. Addons catalogs are available via the Data Download New Data... submenu where you can download catalogs provided by &kstars; team and the community. Furthermore, &kstars; supports import of custom catalogs. To import a raw ASCII catalog data file into &kstars;, press the Import Catalog and follow the instructions. To import a custom catalog already in &kstars; catalog format, press the Load Catalog button. Each line in the custom catalog file should contain the following space-separated fields:

For stars: type(0 for stars), RA, Dec, mag, SpType, name(optional)

For other types: type(3-8), RA, Dec, mag (optional), flux(optional), name(optional)

The types are:

- 0: star

- 1: star (in object catalog...probably don't want to use this)

- 2: planet (don't use this in custom catalog)

- 3: open cluster

- 4: globular cluster

- 5: gaseous nebula

- 6: planetary nebula

- 7: supernova remnant

- 8: galaxy

- 18: radio source

The SpType is a short string for the spectral type. For example, B5 or G2. The coordinates should be given as floating-point values, in the J2000.0 epoch. The name can be anything you wish. If the name is more than one word, it must be enclosed in quotation marks.

Once you have constructed a custom data file, open the &kstars; configuration window to the Catalogs tab, and press the Import Catalog... button. A popup window appears in which you can specify a name for the catalog, and the name of the file (including the path):

Import Catalog Window Import Catalog Window

When you press Ok button, &kstars; will attempt to read the lines of your data file. It will report any problems, and if any lines at all were successfully parsed, you are given a choice to accept the data file (ignoring any unparsed lines), or to cancel the operation to attempt to resolve the problems first.

You can load a new catalog using the Load Catalog... button. A new window will appear, asking you to specify the file that contains the catalog.

Load Catalog Window Load Catalog Window

Once the data file has been accepted, your custom catalog will be loaded on startup along with the standard catalogs. In the Catalogs window is a checkbox for each catalog which toggles the display of catalog objects.

Add Catalog Add Catalog

Note that, if you want to load a catalog that is already loaded, a warning dialog will pop-up.

Overwrite Catalog Overwrite Catalog

You can remove custom catalogs by highlighting its checkbox in the Catalogs window, and pressing the Remove Catalog... button (this button is active only if a custom catalog is highlighted in the list of checkboxes). Note that it can not be used for removing &kstars; default catalogs.

Delete Catalog Delete Catalog

For radio sources catalogs, you must include the flux frequency and units. For example:

    # Flux Frequency: 1420 Mhz
    # Flux Unit: mJy

The following is a simple catalog file:

    # Name: my_catalog
    # Prefix: et_radio
    # Color: #00ff00
    # Epoch: 2000
    # Flux Frequency: 1420 Mhz
    # Flux Unit: mJy
    # ID  RA  Dc  Tp  Mj  Mn  PA  Nm  Flux
    J0001 12:31:23.1 +11:29:34 18 180.60 360.30   45  my_radio_source   70

Using the Catalogs window, you can define faint limits for sky objects for zoomed in and zoomed out states of the rendering. When the Show objects of unknown magnitude item is enabled, objects whose magnitudes are unknown, or not available to &kstars;, are drawn irrespective of the faint limits set.

The following is a brief tutorial on adding new catalogues to &kstars;. To import a new catalog, download a raw catalog data file where the data columns are space delimited. Any lines starting with # shall be ignored. For this example, we shall use the Lynds Catalog of Dark Nebulae.

- Download / write the raw catalog data file (the raw file is the file containing catalog's objects described by a set of parameters, like: ID Number, Right Ascension, Declination and so on).

  In order to successfully load a custom catalog into &kstars;, you need to use the following syntax: (otherwise your catalog will be entirely ignored or maybe some objects from your catalog will be wrongly drawn)

  - Every object should be written on a separate row.

  - The fields of each line should be separated by white space.

  - The catalog header may contain comment lines beginning with the # symbol.

  - ID number: integer value.

  - Right Ascension: colon-delimited hh:mm:ss.s or floating-point value.

  - Declination: colon-delimited dd:mm:ss.s or floating-point value.

  - Object type: integer value, one of [ 0,1,2,3,4,5,6,7,8 ].

  - Common name: string value (if it contains a space, it *must* be enclosed in quotes!).

  - Magnitude: floating-point value.

  - Major axis: floating-point value (length of major axis in arcmin).

  - Minor axis: floating-point value (length of minor axis in arcmin).

  - Position angle: floating-point value (position angle, in degrees).

  The following is a subset of the original raw data file:

         1 16 26.0   -16  0    .18 +21.82    .054 3  49    8  452
         2 18  4.0   -31 30    .13 -05.32   1.240 2   0    4  837
         3 18  0.0   -31  0    .15 -04.33   5.600 2   0    6  817
         4 16 59.5   -22  8    .18 +11.82    .004 5  27    7  533
         5 17 13.2   -24 22    .20 +07.96    .012 4   0    9  595

  The raw file contains some extra information, unusable for &kstars;. It also contains extra white spaces and values are not meeting &kstars; expectations (&ie; for Right Ascension: colon-delimited hh:mm:ss.s or floating-point value). Thus, it need to be modified in order to match &kstars; format. For a better understanding on what each column means, you can take a look at the original source of the catalog. It contains the raw data file and, in addition, it contains an useful readme, which will help you understand what you should keep and furthermore, what you need to remove from the raw data file. Minimally, the raw data file should contain the following fields:

  - ID Number

  - Object Type

  - Right Ascension

  - Declination

  The raw Dark Nebulae by Lynds contains only three usable fields for &kstars;: Right Ascension, Declination and Area (square degrees). Therefore, in order to properly import the catalog into &kstars;, the ID and Object Type fields need to be added. You can insert these values manually using your favorite text editor. However, it is recommended to use any spreadsheet application to import the raw data file and add the necessary columns. This is especially convenient for large data sets. Since the original raw data contains an area field which is not supported by &kstars;, we need to approximate it to a usable value which is the Major Axis. Therefore, we use the following formula in the spreadsheet to convert area to major axis in arcminutes: `Major Axis = sqrt(Area) * 60`

  After importing the raw data file into &kstars; and selecting the appropriate columns, &kstars; shall generate the final catalog file suitable for loading directly into &kstars;. For example, this is a small subset of the content (header + first five objects) of the Dark Nebulae by Lynds catalog which was created by &kstars; after importing the raw data file which only contains the data columns:

      # Delimiter:
      # Name: LyndsCatalog
      # Prefix: Lynds
      # Color: #ff7600
      # Epoch: 2000
      # ID  RA  Dc  Mj  Tp
      1 16:26:0 -16:0:0.1 13.943 5
      2 18:4:0 -31:30:0.1 66.813 5
      3 18:0:0 -31:0:0.1 141.986 5
      4 16:59:5 -22:8:0.1 3.795 5
      5 17:13:2 -24:22:0.2 6.573 5

  As seen above, each column was assigned a &kstars; designated header such as the ID, Right Ascension, Declination, Major axis and Object Type fields. Note that the Catalog Prefix (Lynds) and the ID field are used together for identifying objects in the Sky Map (&ie; objects from this catalog will have names like: Lynds 1, Lynds 2, Lynds 617 up to the last object, Lynds 1791).

- Open the Settings Configure &kstars;... menu and choose Catalogs tab.

- In the Deep-Sky objects section, press the Import Catalog... button. If the button is not available, check the Deep-Sky Catalogs checkbox. This will enable you to configure &kstars; deep-sky objects catalogs.

- After you press the Import Catalog... button, Import Catalog window will pop up. At first, click on Open file dialog button in order to select the raw data file. Import catalog Import new catalog

- In the dialog window, find your raw file, select it and then press Open button. Open catalog Open Dark Nebulae catalog

- Now, you need to specify the correct order of the catalog fields within the raw data file. The fields must be added inside Catalog fields list. Note that you can drag fields in order to build the right order or you can use additional fields from Available fields fields. For example, if your raw data file contains a magnitude column, then you need to add Magnitude field to the Catalog fields list. Complete info for new catalog Complete info for new catalog

- After you set the fields so that they match to your catalog raw file, you can move to the next step: completing the remaining input fields: Coordinate epoch, Catalog name prefix, Catalog name and Save catalog as. You can also choose the Symbol color used for your catalog. There you can specify how the fields are split within the raw data file: CSV (Comma-separated values) or Space Delimited.

- You can preview the output by pressing the Preview Output button. Pay attention to the header fields to have the same order as your catalog fields (&ie; ID RA Dec Major Axis and Object Type).

- Press OK button to close the Catalog Preview window. Then press OK button again to create and save your catalog.

- After you successfully imported your catalog, it will be displayed in the catalogs list. You can choose to be displayed or not, by pressing on its checkbox. Added Dark Nebulae by Lynds catalog Dark Nebulae by Lynds catalog

## Solar System

Solar System Window Solar System Window

In the Solar System page, you can specify whether the Sun, Moon, planets, comets and asteroids are displayed, and whether the major bodies are drawn as colored circles or actual images. You can also toggle whether solar system bodies have name labels attached, and control how many of the comets and asteroids get name labels. There is an option to automatically attach a temporary orbit trail whenever a solar system body is tracked, and another to toggle whether the color of the orbit trail fades into the background sky color.

## Satellites

Satellites Window Satellites Window

The Satellites page allows you to set the satellites view options. Firstly, you can see or hide the satellites on the skymap using Show satellites checkbox from the top View options section. By default, satellites are drawn as small light red filled circles with an optional dark red name label next to them. You can enable or disable these labels by checking or not the Show labels checkbox. It is located below the Show satellites checkbox, within the View options section.

The colors of the dots representing satellites and their name labels can be easily customized using the Colors page from the same Configure &kstars; window. In addition, satellites can be drawn just like regular stars by checking the Draw satellites like stars checkbox. To display only the visible satellites from your current geographic location and time, select Show only visible satellites.

&kstars; can draw artificial satellites from many predefined groups. Thus, you can select to display a particular group, multiple groups or partially select subgroups. Under each group, a list of individual satellites is presented. To select all satellites from a group, you need to check the group checkbox. You can also select only the satellites of interest in each group. The satellites orbital elements can be updated via the internet by pressing the Update TLEs button. Another way for updating the satellites orbital elements is to use the Updates Update satellites orbital elements in the Data menu. If you know the name of a desired satellite then you can use the search satellites method that &kstars; provides. You need to enter the name of satellite in the Search satellites text box and the list will be reduced only to its best matches.

You can add new satellites to &kstars; default satellites set by editing the `kstars/data/satellites.dat` file. As each line of this file is a group of satellites, you need to add a new entry for your desired satellites group. An entry should have the following format: `Group Name;local_filename;url`. For example: `Iridium;iridium.tle;http://celestrak.com/NORAD/elements/iridium.txt`.

## Supernovae

Supernovae Window Supernovae Window

The Supernovae page allows you to decide if the supernovae are displayed or not by checking the Show supernovae checkbox. By default, supernovae are drawn as small light orange + mark. As for satellites, the color of supernovae can be easily customized using the Colors page.

You can configure &kstars; to check for newly discovered supernovae on startup by checking the Check for Recent Supernovae on Startup checkbox. This way, &kstars; will be always up-to-date with the most recent supernovae. You can enable supernova alerts using the Enable Supernova alerts checkbox. Thus, &kstars; will automatically alert you every time it learns of a new supernova in the sky. You can set the magnitude limit for showing a supernova as well as magnitude limit for supernova alerts using the spin boxes control. The limiting magnitude is the faintest apparent magnitude of an skyobject that is visible with the naked-eye or a telescope.

The list of recent supernovae can be updated via the internet by pressing the Update List of Recent Supernovae button. Another way for updating the supernovae list is to use the Updates Update Recent Supernovae data item in the Data menu.

## Guides

Guides Window Guides Window

The Guides page lets you toggle whether non-objects are displayed (&ie;, constellation lines, constellation names, the Milky Way contour, the celestial equator, the ecliptic, the horizon line, and the opaque ground). You can also choose whether you would like to see Latin constellation names, IAU-standard three-letter abbreviations, or constellation names using your local language.

## Colors

Colors Window Colors Window

The Colors page allows you to set the color scheme, and to define custom color schemes. The tab is split into two panels:

The left panel shows a list of all display items with adjustable colors. Click on any item to bring up a color selection window to adjust its color. Below the list is the Star Color Mode selection box. By default, &kstars; draws stars with a realistic color tint according to the spectral type of the star. However, you may also choose to draw the stars as solid white, black or red circles. If you are using the realistic star colors, you can set the saturation level of the star colors with the Star Color Intensity spinbox.

The right panel lists the defined color schemes. There are four predefined schemes: the Default Colors scheme, Star Chart, which uses black stars on a white background, Night Vision, which uses only shades of red in order to protect dark-adapted vision, and Moonless Night, a more realistic, dark theme. Additionally, you can save the current color settings as a custom scheme by clicking the Save Current Colors button. It will prompt you for a name for the new scheme, and then your scheme will appear in the list in all future &kstars; sessions. To remove a custom scheme, simply highlight it in the list, and press the Remove Color Scheme button.

## FITS

FITS (Flexible Image Transport System) is a popular open standard for storage, transmission and processing of digital data. For the details, one is referred to the corresponding Wikipedia article. This page allows you to configure presentation and processing of FITS data in &kstars;.

The left panel is for configuring FITS viewer itself.

Check the Use FITS Viewer item if you want automatically display received images in the FITS Viewer.

The Single Preview Tab item is to display all captured FITS images in a single tab instead of multiple tabs per image. The Single Window Capture item is to display captured FITS images from all cameras in a single FITS Viewer window instead of a dedicated window to each camera. The Single Window Open item is to display opened FITS images in a single FITS Viewer window instead of a dedicated window to each file and the Independent Window item is to make FITS Viewer window independent from &kstars;.

The right panel lists processing options. The Auto Stretch item is to always apply auto stretch to images in FITS Viewer, Limited Resources Mode is to enable limited resource mode to turn off any resource-intensive operations, namely: Auto Debayer (bayered images will not be debayered; only grayscale images are shown), Auto WCS (World Coordinate System data will not be processed; WCS maps sky coordinates to image coordinates; equatorial grid lines, object identification, and telescope slew within an image are disabled), and 3D Cube (RGB images will not be processed; only grayscale images are shown). You can switch off some of these resource-greedy operations separately as well.

## INDI

INDI Window INDI Window

For detailed explanation of the options on the INDI page see the Configure INDI section.

## Ekos

Ekos Window Ekos Window

Ekos is an astrophotography suite, a complete astrophotography solution that can control all INDI devices including numerous telescopes, CCDs, DSLRs, focusers, filters, and a lot more. Ekos supports highly accurate tracking using online and offline astrometry solver, autofocus and autoguiding capabilities, and capture of single or multiple images using the powerful built in sequence manager. For detailed explanation of Ekos, see the official Ekos page.

## Advanced

Advanced Window Advanced Window

The Advanced page provides fine-grained control over the more subtle behaviors of &kstars;.

The Correct for atmospheric refraction checkbox controls whether the positions of objects are corrected for the effects of the atmosphere. Because the atmosphere is a spherical shell, light from outer space is bent as it passes through the atmosphere to our telescopes or eyes on the Earth's surface. The effect is largest for objects near the horizon, and actually changes the predicted rise or set times of objects by a few minutes. In fact, when you see a sunset, the Sun's actual position is already well below the horizon; atmospheric refraction makes it seem as if the Sun is still in the sky. Note that atmospheric refraction is never applied if you are using Equatorial coordinates.

The Use animated slewing checkbox controls how the display changes when a new focus position is selected in the map. By default, you will see the sky drift or slew to the new position; if you uncheck this option, then the display will instead snap immediately to the new focus position.

If the Attach label to centered object checkbox is selected, then a name label will automatically be attached to an object when it is being tracked by the program. The label will be removed when the object is no longer being tracked. Note that you can also manually attach a persistent name label to any object with its popup menu.

There are three situations when &kstars; must redraw the sky display very rapidly: when a new focus position is selected (and Use animated slewing is checked), when the sky is dragged with the mouse, and when the time step is large. In these situations, the positions of all objects must be recomputed as rapidly as possible, which can put a large load on the CPU. If the CPU cannot keep up with the demand, then the display will seem sluggish or jerky. To mitigate this, &kstars; will hide certain objects during these rapid-redraw situations, as long as the Hide objects while moving checkbox is selected. The timestep threshold above which objects will be hidden is determined by the Also hide if time step larger than: timestep-spinbox. You can specify the objects that should be hidden in the Configure Hidden Objects group box.

## Customizing the Display

There are several ways to modify the display to your liking.

- Select a different color scheme in the Settings Color Schemes menu. There are four predefined color schemes, and you can define your own in the Configure &kstars; window.

- Toggle whether the Toolbars are drawn in the Settings Toolbars Shown menu. Like most KDE toolbars, they can also be dragged around and anchored on any window edge, or even detached from the window completely if they are unlocked.

- Toggle whether the Info Boxes are drawn in the Settings Info Boxes menu. In addition, you can manipulate the three Info Boxes with the mouse. Each box has additional lines of data that are hidden by default. You can toggle whether these additional lines are visible by double-clicking a box to shade it. Also, you can reposition a box by dragging it with the mouse. When a box hits a window edge, it will stick to the edge when the window is resized.

- Choose an FOV Symbol using the Settings FOV Symbols menu. FOV is an acronym for field-of-view. An FOV symbol is drawn at the center of the window to indicate where the display is pointing. Different symbols have different angular sizes; you can use a symbol to show what the view through a particular telescope would look like. For example, if you choose the 7x35 Binoculars FOV symbol, then a circle is drawn on the display that is 9.2 degrees in diameter; this is the field-of-view for 7x35 binoculars.

  You can define your own FOV symbols (or modify the existing symbols) using the Edit FOV Symbols... menu item, which launches the FOV Editor:

  Field-of-View Symbols Editor FOV Symbol Editor

  The list of defined FOV symbols is displayed on the left. On the right are buttons for adding a new symbol, editing the highlighted symbol's properties, and removing the highlighted symbol from the list. Note that you can even modify or remove the four predefined symbols (if you remove all symbols, the four defaults will be restored the next time you start &kstars;). Below these three buttons is a graphical preview display showing the highlighted symbol from the list. When the New... or Edit... button is pressed, the New FOV Indicator window is opened:

  New Field-of-View Symbol New FOV Symbol

  This window lets you modify the four properties that define a FOV symbol: name, size, shape, and color. The angular size for the symbol can either be entered directly in the Field of View edit box, or you can use the Eyepiece/Camera Tabs to calculate the field-of-view angle, given parameters of your telescope/eyepiece or telescope/camera setup. The five available shapes are: Square, Circle, Crosshairs, Bullseye and Semitransparent circle. Once you have specified all four parameters, press Ok, and the symbol will appear in the list of defined symbols. It will also be available from the Settings FOV Symbols menu.

&hips;