Matt Jones

How to add Comet Lulin to Stellarium

lulin

If you’re in the Northern Hemisphere, the best time to see Comet Lulin will be when it passes Saturn and heads towards Regulus in the constellation of Leo from the 23rd of February onwards. It should be visible to the naked eye if you have clear skies and should look pretty good through binoculars.

A good way to track its progress – and find out how to spot it – is to use Stellarium. Stellarium is a piece of open source, cross-platform Planetarium software which has a database of 600,000 stars and other astronomical objects. However, a vanilla installation doesn’t have information about comets, so you have to add Lulin yourself.

To do this, you need to edit the Stellarium configuration file called ‘ssystem.ini’. This is found in different places depending on your operating system (note: you’ll probably need an admin/root password to do this):

Linux: /usr/share/stellarium/data/ssystem.ini
Mac: /Applications/stellarium.app/data/ssystem.ini (ctrl-click on the Stellarium.app icon >’ Show package contents’)
Windows: C:Program Files\Stellarium\data\ssystem.ini

At the bottom of the ssystem.ini file, add the following:

[lulin]
name = C/2007 N3 (Lulin)
parent = Sun
radius = 100
oblateness = 0.0
halo = true
color = 1.0,1.0,1.0
tex_halo = star16x16.png
tex_map = nomap.png
coord_func = comet_orbit
orbit_TimeAtPericenter = 2454842.112213313327
orbit_PericenterDistance = 1.211815031505141
orbit_Eccentricity = 1.000243857235593
orbit_ArgOfPericenter = 136.8421983153854
orbit_AscendingNode = 338.5047481504214
orbit_Inclination = 178.3725975895116
lighting = false
albedo = 1
orbit_visualization_period = 10000000000

Credit goes to Robert9 for the posting the above to this this forum, which is in turn based on data from the JPL Horizons database.

Once you save the file and run Stellarium, you should see Comet Lulin appear. Happy Comet watching!

8 Responses to “How to add Comet Lulin to Stellarium”

  1. 3:53 pm on 23 February 2009 :::

    shoe carnival Says:

    Thanks. ^_^

  2. 7:18 pm on 23 February 2009 :::

    Cooper Strange Says:

    Thanks a lot! I had to pour over pages and pages of bad explanations of where exactly to find Lulin. I did finally find it, the hard way with non-interactive charts, but after installing Stellarium, your input here helped confirm what I thought I had figured out. Plus…what a cool program! I will love using that in the future.

  3. 9:03 am on 24 February 2009 :::

    Ewan Says:

    Brilliant, thanks for that.

  4. 8:14 am on 25 February 2009 :::

    Dominic Says:

    Thanks for the tutorial !

  5. 5:18 pm on 25 February 2009 :::

    Matt Jones » Blog Archive » @jodrellbank I’ve written up h… Says:

    [...] @jodrellbank I’ve written up how to add Lulin to Stellarium. http://mattjon.es/blog/2009/02/1817/ [...]

  6. 10:33 am on 26 February 2009 :::

    How to Track Comet Lulin with Stellarium Says:

    [...] a tweet from @mattjones yesterday pointing to a great post on his blog that shows you how to configure Stellarium to allow you to follow comet Lulin.  Comets are [...]

  7. 10:47 am on 26 February 2009 :::

    Steve Dangerfield Says:

    Thanks for this great post, just tried it in Stellarium and it works a treat! Just need some clear skies in Yorkshire to give it a try :-)

  8. 11:42 pm on 28 February 2009 :::

    PipeSmokingMan Says:

    thanks! a friend of mine asked me today “Hey, WHERE is that green comet they are talking about…???” – I fired up Stellarium – errr… – nothing.
    Your post helped me out. ;-)
    BTW – you say a vanilla install does not have any comets in it – is there any add-on catalogue that would add the usual known suspects to Stellarium?
    Cheers from Germany
    Martin

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