Celestia Forums

... under osX.

This is not a bug but I'm wondering if the situation is the same under Windows and Linux...

First the Solar System Barycenter appear listed in "Brightest stars" and "Nearest stars"; as the SSB is not a star I find this is not making much sense...

Next, in "Stars with planets" we can find Sol; of course Sol is a star with planets, but we have a special item call "Home (Sol)" for this special case... IMHO it would be better to call "Stars with planets" "Others stars with planets" and remove Sol from this listing.

Now in "Home (Sol)" we can find "Pluto" and "Pluto-Charon".
Here again several things to say: as "Pluto-Charon" is a barycenter I wonder if we could not have a new Item next to Spacecrafts, Asteroids and Comets called "Barycenters" in which we could find the SSB and Pluto-Charon.
In all case, something strange: under Pluto we have Charon and under "Pluto-Charon" we have Nix and Hydra. As Pluto and Charon are orbiting "Pluto-Charon" couldn't we simplify and have all those 4 body under "Pluto-Charon"?
But, BTW, Pluto is still a planet?

No, the August 24th 2006 the IAU defined officially only 8 major planets :
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
and 4 minor planets :
Ceres, Pluto, Charon and "2003 UB313" (First called Xena and finally Eris ?)

Quid of Sedna, "2005FY9", Orcus, Quaoar etc...?

ElChristou wrote:First the Solar System Barycenter appear listed in "Brightest stars" and "Nearest stars"; as the SSB is not a star I find this is not making much sense...

I'm not seeing this. It lists Sol in both situations for me.

ElChristou wrote:Next, in "Stars with planets" we can find Sol; of course Sol is a star with planets, but we have a special item call "Home (Sol)" for this special case... IMHO it would be better to call "Stars with planets" "Others stars with planets" and remove Sol from this listing.

I disagree here. Sol is a star with planets. I feel that it needs to stay in that list for consistency. Besides, it may be the star we live near, but it's still just a random star in the universe, nothing special.

ElChristou wrote:Now in "Home (Sol)" we can find "Pluto" and "Pluto-Charon".
Here again several things to say: as "Pluto-Charon" is a barycenter I wonder if we could not have a new Item next to Spacecrafts, Asteroids and Comets called "Barycenters" in which we could find the SSB and Pluto-Charon.

I agree. And Pluto needs to be removed from the list of planets when you right-click on Sol.

ElChristou wrote:In all case, something strange: under Pluto we have Charon and under "Pluto-Charon" we have Nix and Hydra. As Pluto and Charon are orbiting "Pluto-Charon" couldn't we simplify and have all those 4 body under "Pluto-Charon"?

In the Windows version of 1.5.0, Nix and Hydra aren't even there.

Johaen wrote:I disagree here. Sol is a star with planets. I feel that it needs to stay in that list for consistency. Besides, it may be the star we live near, but it's still just a random star in the universe, nothing special.

Of course it is, but on osX we have the "Home(Sol)" where you can also browse the Solar System; if Sol stay in "Stars with planets", IMO this item should be removed (double use)...

ElChristou wrote:In all case, something strange: under Pluto we have Charon and under "Pluto-Charon" we have Nix and Hydra. As Pluto and Charon are orbiting "Pluto-Charon"

Sorry if I'm restating the obvious.. so Charon isn't really orbiting Pluto, it's orbiting the Pluto-Charon barycenter? And so are Nix and Hydra?

As a side note, it's my understanding that barycenters are invisible and thus not right-clickable. That's why it's no longer possible to right click and see all moons of Pluto, since Nix and Hydra are no longer moons of any visible object. One ought to be able to right click the visible planet of Pluto and see Nix and Hydra - if you can't, it's probably a bug.

dirkpitt wrote:

ElChristou wrote:In all case, something strange: under Pluto we have Charon and under "Pluto-Charon" we have Nix and Hydra. As Pluto and Charon are orbiting "Pluto-Charon"

Sorry if I'm restating the obvious.. so Charon isn't really orbiting Pluto, it's orbiting the Pluto-Charon barycenter? And so are Nix and Hydra?

In numberedmoons.ssc, Hydra and Nix are declared orbiting Puto-Charon, but in the solarsys.ssc Pluto is declared orbiting Sol but use as reference frame Pluto-Charon, and Charon is declared orbiting Pluton but also use as reference frame Pluto-Charon... I suppose the browser is unable to use reference frame to correctly sort the bodies... ...or Pluto and Charon should be declared orbiting Pluto-Charon?

In Celestia v1.5.0, paths used for selection do not have to be the same as paths used for orbital mechanics (Frames). Frame paths can be long and complex, but selection paths should be kept short.

Unfortunately, I have the impression that not all of the display code takes this into account.

ElChristou wrote:In numberedmoons.ssc, Hydra and Nix are declared orbiting Puto-Charon, but in the solarsys.ssc Pluto is declared orbiting Sol but use as reference frame Pluto-Charon, and Charon is declared orbiting Pluton but also use as reference frame Pluto-Charon

Now I understand. Pluto should have as moons Charon, Nix, Hydra. The invisible object "Pluto-Charon" should be listed separately in a category called "Reference Frames", and should show as "children" all the objects that refer to it (which in this case is Pluto, Charon, Nix, and Hydra).

dirkpitt wrote:

ElChristou wrote:In numberedmoons.ssc, Hydra and Nix are declared orbiting Puto-Charon, but in the solarsys.ssc Pluto is declared orbiting Sol but use as reference frame Pluto-Charon, and Charon is declared orbiting Pluton but also use as reference frame Pluto-Charon

Now I understand. Pluto should have as moons Charon, Nix, Hydra. The invisible object "Pluto-Charon" should be listed separately in a category called "Reference Frames", and should show as "children" all the objects that refer to it (which in this case is Pluto, Charon, Nix, and Hydra).

Actually I suppose we should have in the category "Home" (if Pluto is still considered a planet within Celestia):



Note I have add a (Barycenter) that could be in grey (like for the galaxies) for better understanding...

There was an inconsistency in the way that Nix and Hydra were defined in numberedmoons.ssc. I changed the definitions so that their parent object is Pluto, but their orbits are still defined with respect to the Pluto-Charon barycenter. Charon, Nix, and Hydra now all appear as children of Pluto in the solar system browser.

I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

--Chris

chris wrote:I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

--Chris

I think the browser should show everything.
Perhaps an alternative could be to ignore objects preceded by a special character such as an underscore, and this would leave it up to addon creators as to which objects are displayed in the browser.

Chuft-Captain wrote:

chris wrote:I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

--Chris

I think the browser should show everything.
Perhaps an alternative could be to ignore objects preceded by a special character such as an underscore, and this would leave it up to addon creators as to which objects are displayed in the browser.

That's a sensible proposal . . . Any one else care to offer an opinion?

--Chris

chris wrote:...I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

IMO Barycenter should be present, it's a way to call the attention of the public on a not so known element of planetary mechanic... (after all selecting Pluto-Charon is cool to see how bodies rotate around it...)

ElChristou wrote:

chris wrote:...I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

IMO Barycenter should be present, it's a way to call the attention of the public on a not so known element of planetary mechanic... (after all selecting Pluto-Charon is cool to see how bodies rotate around it...)

I suppose that a better way to resolve the problem is to show every solar system object, but group them into categories: planets, minor planets, spacecraft, and reference points.

--Chris

chris wrote:

ElChristou wrote:

chris wrote:...I also changed the Windows solar system browser to ignore invisible objects (like reference points.) This prevents Pluto and Pluto-Charon from both appearing in the solar system browser. Do people agree that this is a good idea?

IMO Barycenter should be present, it's a way to call the attention of the public on a not so known element of planetary mechanic... (after all selecting Pluto-Charon is cool to see how bodies rotate around it...)

I suppose that a better way to resolve the problem is to show every solar system object, but group them into categories: planets, minor planets, spacecraft, and reference points.

--Chris

You mean whithout the parent/children classification?