Celestia Forums

I added a Julian Date setting to the OS X version. This allows you to set Celestia's time to a Julian Date (e.g., 2755511.5000). This option was also recently added to the Windows version.

It's not in CVS yet, but you can try it out in my unofficial build: Unofficial 2007-12-17 build

To test it, hit Cmd+T to pop up the Set Time panel. Entering a date like 12/17/2007 will cause the Julian date to update and vice versa. You can easily confirm that special Julian dates like "0" get you back the correct reference date 1/1/-4712, where the minus sign means "BCE". **

**this minus format is zero-based, so "-4712" means "4713 BCE". I'm following the Unicode Standard #35 which says "0" = 1 BCE.


Also by request from ElChristou, spectral types have been added to star names in the Browser. For example, Sol now reads "Sol (G2V)". However, I personally find that after having added the spectral type to all the names... it seems to make things more confusing and cluttered. I doubt that many people will look at codes like K2V, T6V, and DZ7, and instantly know what they mean. (ElChristou? Can you tell me what "DZ7" means? )

Dirkpitt,

I tested your built, and I noticed two small "glitches" in the browser :

1- There's a star "family" (stars with planetary objects) for which the spectral class isn't shown the same way (fully black) as for the others (grayed). Do you confirm ?

2- For consistency, the Hubble class should also be shown for the galaxies.

dirkpitt wrote:However, I personally find that after having added the spectral type to all the names... it seems to make things more confusing and cluttered. I doubt that many people will look at codes like K2V, T6V, and DZ7, and instantly know what they mean

I tend to agree with this view.

I fixed a bug discovered by Cham in the Julian Date setting where BCE years were not being recognized in certain cases. Also, for consistency BCE years now follow Unicode #35 regardless of platform, so Julian Date = 0 is -4712 on both PPC and Intel Macs (although a bug remains where year 0 (1 BCE) is not working). Finally, a French translation for "Julian Date" has been added (thanks Cham)

The download link has been updated with the new build ("20071217p").

Regarding spectral type tags, I'm thinking I'll probably remove them since they're more clutter than I'd expected. Might there a way I could keep the tags, but improve the presentation? Color coding? Shorter labels?

I think that showing the spectral classes (and Hubble type) is premature. It should be part of some search and filter option, which could be added later.

I agree with Da Woon that the browser is getting a bit confused and cluttered. I suggest to remove all the spectral classes, until we get some search and filter capabilities.

And how is it on the other platforms ? Do they have the spectral classes indicated in their browser ? If not, then for consistency, we shouldn't have the spectral classes indicated in the OS X browser.

The KDE version's browser displays a lot of info.

While the effort to add spectral type tags was relatively minor, it unfortunately did not appear to offer any improvements in usability (to me at least). More substantial improvements, such as those offered by the KDE version's browser, are probably best deferred to the upcoming cross-platform UI.

Hmmm, definitely, the KDE version appears to be vastly superior.

I added a Julian Date setting to the OS X version. This allows you to set Celestia's time to a Julian Date (e.g., 2755511.5000). This option was also recently added to the Windows versi

Dirkpitt,
This is a very nice function to have, but it only works one way: entering a gregorian date will show the julian, but entering a julian will either create a wildly wrong gregorian, or just a message that no date was entered. Haven??t found out yet why sometimes the one happens and why sometimes the other, but will watch it - as i use it all the time.

- rthorvald

It should work both ways (Julian->Gregorian, Gregorian->Julian). Have you tried one of Steve Binder's builds (works for me)? Try entering the Julian as a number, e.g., 200000.

Have you tried one of Steve Binder's builds (works for me)? Try entering the Julian as a number, e.g., 200000.

Can you provide us a link to Steve Binder's builds, I’d like to see how it works.

You should search for Steve's profile to find a link to his webpage...