Any Plans For Extrasolar Planets?

[peter_89]

This isn't really a suggestion (which is why I did not place this in the suggestion thread) but I am just wondering if there are any plans to create any of the 190 currently discovered extrasolar planets for Celestia.

[chris]

This isn't really a suggestion (which is why I did not place this in the suggestion thread) but I am just wondering if there are any plans to create any of the 190 currently discovered extrasolar planets for Celestia.

All of the currently known extrasolar planets are already included with Celestia. Some of the very recent discoveries aren't in Celestia 1.4.1, but they are checked into the CVS tree.

--Chris

[peter_89]

I've tried entering in extrasolar planetary names, from all sorts of discovery dates and statistics, and none of them even register. What am I doing wrong? Is there some sort of add-on I need?

[selden]

In order to select a planet, you first must select its star.

Here's one way to view an extra-solar planet if you're using the Windows version of Celestia:

select the menu Navigation/ Star Browser...
In the popup window, select "with planets"
select the star that interests you
select goto
select OK

select the menu Navigation/ Solar System browser

select the planet that interests you
select goto
select OK

[ajtribick]

Put a forward slash after the star name. E.g. to select 51 Peg b, use "51 Peg/b"

[peter_89]

Thanks guys!

[tizerist]

are the colours of the extra solar planets real?
i thought noone could tell colours of them just yet...

[ajtribick]

are the colours of the extra solar planets real?
i thought noone could tell colours of them just yet...

The textures of gas giant planets are based on the paper Albedo and Reflection Spectra of Extrasolar Giant Planets by Sudarsky, Burrows and Pinto. The paper models the atmospheres of giant planets and divides them into 5 different classes:

I = ammonia clouds (e.g. Jupiter)
II = water clouds
III = cloudless
IV = alkali metal absorption
V = silicate/iron clouds

The paper also includes theoretical spectra for each of these classes, which were integrated by Grant Hutchison to give RGB values used for the planet dots at large distances. The actual textures used may differ somewhat from these colours (at some point I should have a go at fixing this) - this is because of the history of implementing the five-class system in Celestia: I created the textures before I had the integration results. In the cases of classes I to III the textures are OK, but it's fairly obvious that classes IV and V have rather different colours in close-up than at large distances.

I'd be somewhat cautious about the classes as displayed: the algorithm used for assigning these classes doesn't match the results given in that paper (or the follow-up paper Theoretical Spectra and Atmospheres of Extrasolar Giant Planets by Sudarsky, Burrows and Hudeny). In part, this is because stellar temperatures in Celestia are limited to standard values for each spectral type, internal heating of the planets is not taken into account (e.g. 55 Cnc d would probably be in class II rather than class I as depicted), and also the planet's gravity plays a role (e.g. many of the planets assigned to class IV may have low enough gravity to go up to class V). Also, the algorithm relies on the planet temperature, when to do this properly you have to model the temperature/pressure profile of the planet's atmosphere and see if it intersects the condensation curves of various substances (e.g. ammonia, water, forsterite, etc).

[ajtribick]

...I should also get around to updating the textures to include simulated flow patterns. Synchronously-rotating gas giants are predicted to have very different flow patterns from rapidly rotating outer planets.

[Kolano]

That would be greatly appriciated chaos syndrome!

I was thinking about that just the other day (i.e. planet types something like galaxy types for extrasolar planets where no reasonable imaging of their will likely ever occur).