Catalogs

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 catalog is the New General Catalog (“NGC”) including the Index Catalog (“IC”) and the Messier Catalog.

Le catalogue NGC inclut environ 7 840 objets du ciel profond.

Le catalogue IC complète le catalogue NGC avec quelques 5 386 objets supplémentaires.

You can install new catalogs using KStars “Add-On Installer”. You can open it via the Data → Download New Data... menu item. You can choose from a list of catalogs, including (but not limited to):

• Le catalogue NGC/IC de Steinicke qui est un catalogue plus complet que le NGC/IC.

• Le catalogue des nébuleuses planétaires de Abell contenant 86 nébuleuses planétaires. La magnitude maximale est atteinte par le 47 ième objet dont la valeur est 19,5.

• Le catalogue « Sharpless » de la région « HII » (Sh2) contient les régions des nébuleuses diffuses.

• Les groupes compacts de Hickson forment un catalogue contenant un groupe compact de 99 galaxies.

• Le catalogue Tycho-2 Star contient plus de 2,5 millions d'étoiles les plus brillantes. Il contient des étoiles de magnitude allant de 8,0 à 12,5.

• Le catalogue NOMAD USNO contient plus de 100 millions d'étoiles de magnitude 12,5 à 16.5. Veuillez noter que le catalogue Tycho-2 doit être préalablement installé.

The following is a summary of catalogs in KStars:

Table 3.1. Stars Catalogs

Nom	Abréviation	Nombre d'objets	Magnitude
Catalogue par défaut	Défaut	~300 000	Jusqu'à la magnitude 8
Tycho-2	Tycho2	plus de 2,5 millions	8,0 - 12,5
Ensemble de données NOMAD	USNO NOMAD	100 millions	12,5 - 16,5

Table 3.2. Deep-sky objects Catalogs

Nom	Abréviation	Nombre d'objets	Magnitude
Nouveau catalogue général (NGC) des nébuleuses et des amas d'étoiles (OpenNGC)	NGC	7,840
Steinicke NGC/IC
Catalogue Abell des nébuleuses planétaires		86	Jusqu'à la magnitude 19,5
Catalogue Sharpless des régions HII	Sh2
Groupes compacts de Hickson		99

Note

A potentially more up-to-date listing can be found in the catalog repository documentation.

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... menu item where you can download catalogs provided by KStars team and the community through the catalog packaging repository. The DSO minimal zoom: slider controls the minimal zoom level for which the DSOs are shown. Increasing the minimal zoom level can lead to performance improvements when panning the skymap zoomed-out. The DSO cache percentage: slider regulates how much of the DSO master catalog is being kept in memory. If you experience memory issues with large catalogs, try lowering the percentage. The Label density: slider controls the perceived density of labels for the DSOs. If labels start to overlap and the skymap begins to look too crowded, try tuning this option. The Faint limit zoomed in/out: regulates up to which magnitude objects are shown on the skymap (higher magnitude is fainter). If Show objects of unknown magnitude is ticked, objects of unknown magnitude are always shown.

The following sections will detail how DSO catalogs work in KStars and how they're managed.

La base de données du catalogue du ciel profond (CP)

Note

This section aims at introducing the catalog database of KStars in simple but technical terms. It can be skipped without missing anything essential but helps understanding how to deal with and create (custom) catalogs.

DSO catalogs in KStars are just SQL (sqlite3) database tables. Each catalog is represented by its own table which contains all its objects and an entry in a catalog metadata table. Additionally, catalogs may be imported or exported from and into stand-alone database files.

Chaque objet possède les propriétés usuelles telles que nom et coordonnées mais aussi deux identités. La première est l'identifiant unique de l'objet en question et est calculé par un hachage de tous les champs de l'objet et de l'identifiant du catalogue. Comme des objets peuvent appartenir à plusieurs catalogues, chaque objet possède un identifiant additionnel (OID) qui identifie l'objet physique et peut être partagé par plusieurs objets de différents catalogues.

To speed up object lookup all enabled catalogs are merged into a master table. Each catalog has a priority number and if several objects with the same OID occur the one from the catalog with the highest priority is loaded. The objects from the master catalog are then drawn on the sky and generally available in KStars.

Currently, deduplication (the assignment of OIDs) is only supported by the tooling of the catalog packaging repository. The aim of this tool-chain is to reproducibly build catalogs in a homogeneous environment. Every catalog is implemented as a python module and provides standard methods to acquire data, parse it and find duplicates in other catalogs. All downloadable catalogs are implemented this way. If you'd like to make a catalog of your own available for KStars, it is recommended that you implement it as a package in the repository. The tooling provided there is so flexible, that it should work for you. For more information on how to do that see the catalog repository documentation. If you are not familiar with python programming you can request the addition of a catalog by opening a ticket in the repository or contacting the maintainers. KStars provides also provides means to create custom catalogs by manually entering data or importing CSV tables, but those are less flexible and offer no deduplication.

The Catalog Management GUI

The catalog management GUI is reached via the Data → Manage DSO Catalogs... menu item and is displayed below.

The DSO catalog management interface.

On the left, a list of catalogs is displayed. In this list, you can read off key catalog properties, including whether a catalog is enabled, what its ID is and what its name is. The Mutable column signifies whether the catalog can be edited or not. Catalogs which have been downloaded from the catalog repository via the Data → Download New Data... menu item are usually immutable whereas user-created catalogs aren't. You can always Clone a catalog to make it mutable.

Les boutons dans le coin gauche du haut vous permettent d'ajouter des catalogues à la base de données.

Import Catalog...

Import a catalog in the .kscat format from a file.

Cela est généralement utilisé pour essayer des nouvelles versions de catalogues qui ne sont pas encore sur les serveurs de téléchargement.

Les boutons dans le coin inférieur droite permettent d'ajouter, modifier et explorer les catalogues. Leurs actions se réfèrent toujours au catalogue courant (la rangée en surbrillance sur la gauche).

Create Catalog...

Create a new catalog. See the section called “Creating a new Catalog”.

Enable / Disable

Activer ou désactiver un catalogue.

This is reflected in the skymap upon closing the catalog management GUI.

Remove

Supprimer un catalogue de la base de données des catalogues.

This is reflected in the skymap upon closing the catalog management GUI.

Export...

Export a catalog into a .kscat file.

The resulting file can be imported with Import Catalog... button.

Clone...

Faire une copie exacte du catalogue et l'insérer dans la base de données.

Cela est utile si vous souhaitez apporter des modifications à un catalogue immuable.

Note

Note however that this is not the recommended way to alter catalogs that are provided by the catalog packaging repository i.e. the catalogs downloaded via the Data → Download New Data... menu item.

Colors

Open the catalog color editor (See the section called “Catalog Color Editor”.).

Cela ouvrira une boite de dialogue où seront affichées les couleurs dans lesquelles les objets seront affichés, et cela pour chaque thème de couleurs.

More...

Open the catalog details dialog. (See the section called “Catalog Details Dialog”.)

Là vous pouvez voir le contenu du catalogue ainsi que des métadonnées. Outre cela, vous pouvez aussi modifier son contenu (s'il est modifiable bien sûr).

Créer un nouveau catalogue

This dialog reached through the catalog management GUI (see the section called “The Catalog Management GUI”). The ID: field will be automatically chosen but can be changed. The Color: field configures in which color the objects of the catalog will be displayed. All the other values are optional or have sensible defaults. You can, of course, change these values at a later point.

Upon clicking Ok an empty catalog with the meta data entered into the dialog will be added to the database and can then be filled with objects. (See the section called “Catalog Details Dialog” and the section called “Importing CSV (and similar formats)”.)

Catalog Color Editor

This dialog reached through the catalog management GUI (see the section called “The Catalog Management GUI”). Each button represents the color that objects will be drawn in for a specific color scheme. Clicking on a button will allow you to choose a color with a color picker. The button colors are initialized with the default colors from the catalog specification. The color "default" is the color which will be chosen for the catalog if there is no color set for a color scheme.

Catalog Details Dialog

This dialog reached through the catalog management GUI (see the section called “The Catalog Management GUI”). In the top left corner, the catalog metadata is being displayed. On the right, a table of all objects in the catalog is being shown. The search line above the table filters objects by name. Double-clicking a row opens the object details dialog (see the section called “Object Details Window”).

Selecting a row enables the Object menu on the left. Selecting multiple rows performs the single-object action for each selected object.

Edit...

Edit the catalog object. (See the section called “Adding/Editing Objects”).

Remove

Supprimer l'objet du catalogue.

Below the Object section, the general catalog options are situated.

Edit Catalog Meta...

Edit the catalog metadata displayed in the top left. This opens the dialog described in the section called “Creating a new Catalog”.

Add Object...

Add an object to the catalog. (See the section called “Adding/Editing Objects”.)

Import CSV...

Import objects from a tabular text format (csv, tsv, etc.) into the catalog. (See the section called “Importing CSV (and similar formats)”.)

Adding/Editing Objects

This dialog allows to create or edit a deep sky object (DSO). The Basics section contains fields that have to be filled in.

Name:

Le nom de l'objet qui sera affiché dans le ciel.

Type:

Le type de l'objet.

RA / Dec (°, J2000):

Les coordonnées de l'objet en degrés et par rapport à l'époque J2000.

Apparent magnitude:

La magnitude apparente de l'objet.

The Optional section contains data fields that are optional, is divided into two subsections. They are set to and can be left at their defaults.

The Size Info in Arcminutes subsection. The object is modeled as an ellipse which is described by its major and minor axis.

The Misc subsection.

Long name:

Un nom plus long, plus descriptif.

Usually, the long name is something like “Andromeda Galaxy” for the object M31. It can contain alternative designations and names in other catalogs as well.

Catalog identifier:

Un identifiant interne du catalogue.

For example the screenshot above, the object originates from the OpenNGC catalog where each row is identified by “NGCXXXX”.

Flux:

Le flux de l'objet. Ne s'applique qu'aux sources radio.

Position angle (°):

Si un objet est étendu, il doit avoir une certaine orientation dans le ciel. L'angle de position est défini comme l'angle de son grand axe et une ligne droite vers le pôle Nord.

Importation CSV (et formats similaires)

The screenshot above shows the CSV import dialog in its default state. In the Input section, you can configure the csv parser. The Comment prefix: is the character that signals commented-out lines in the input. The Separator: should be adjusted to fit your input. Usually, it is “,” or “;” but other separators can occur. Finally, you can choose to skip a number of lines at the beginning of the file. Select/Read button lets you choose a csv file to read with the above configuration. After that, the dialog will look as in the screenshot below.

In the top right you can choose whether coordinates are being expressed in degrees or hours/minutes/seconds. The Mapping section lets you map columns in the CSV file to data fields in KStars. Selecting Ignore assigns the default value for this field. Entering your own text will use this as the value for every object being read. The Type Mapping section maps strings to object types. You can add and remove mappings by clicking + or -. When you're done mapping, you can test your settings by clicking Preview to read the first few objects from the csv. If you are satisfied you can click OK to import the whole catalog or adjust your settings and preview again. As a reference, a mapping for the OpenNGC catalog is shown in the below screenshot.