Quasars plugin

Revision as of 13:21, 10 June 2012

Description

The Quasars plugin provides visualization of some quasars brighter than 16 visual magnitude. A catalogue of quasars compiled from "Quasars and Active Galactic Nuclei" (13th Ed.) (Veron+ 2010).

Example (3C 249.1, also known as LEDA 2821945 or 4C 77.09):

Using the Quasars plugin

1. Enable the tool by clicking the tool-bar button "Load at startup"
2. Find the quasar by their designation (3C 249.1 as example)

Catalog of quasars

You can modify the catalog.json file manually using a text editor. If you are using Windows, it is strongly recommended to use an advanced text editor such as Notepad++ to avoid problems with end-of-line characters. (It will also color the JSON code and make it easier to read.)

Warning: Before editing your catalog.json, make a backup copy. Leaving out the smallest detail (such as a comma or forgetting to close a curly bracket) will prevent Stellarium from starting.

The path to the directory which contains catalog.json is something like:

• C:\Users\UserName\AppData\Roaming\Stellarium\modules\Quasars (Windows Vista, Windows 7)
• C:\Documents and Settings\UserName\Application Data\Stellarium\modules\Quasars (Windows XP)
• HomeDirectory/Library/Preferences/Stellarium/modules/Quasars (Mac OS X)
• ~/.stellarium/modules/Quasars (Linux)

(Note that this is a hidden folder, so in order to find it you may need to change your computer's settings to display hidden files and folders.)

Format of catalog

To add a new quasar, open a new line after line 5 and paste the following, note commas and brackets, they are important:

             "Quasar designation":
             {
                   "RA": "Right ascension (J2000)",
                   "DE": "Declination (J2000)",
                   "Amag": value of absolute magnitude,
                   "Vmag": value of visual magnitude,
                   "z": value of Z (redshift),
                   "bV": value of B-V colour
             },

For example, record for 3C 249.1:

             "3C 249.1":
             {
                   "RA": "11h04m13.8s",
                   "DE": "+76d58m58s",
                   "Amag": -25.1,
                   "Vmag": 15.72,
                   "z": 0.313,
                   "bV": -0.02
             },

Version history

How you can help

We are welcome bug reports, feature requests and feedback through the usual channels (trackers, forums and so on).