Extended time interval

[Atque]

Description

Extends time interval from ±100,000 to ±200,000 years. This corresponds to the given validity of Vondrák's precession model. Possibly, the interval might be extended even further, if the model doesn't break.

Fixes #4500.

Screenshots:

Night sky almost 170,000 years ago.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• This change requires a documentation update
• Housekeeping

Test Configuration:

• Operating system: Windows 11, 64-bit, Qt 6.9.1.
• Graphics Card: irrelevant

Checklist:

• My code follows the code style of this project.
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation (header file)
• I have updated the respective chapter in the Stellarium User Guide
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules

[github-actions]

Great PR! Please pay attention to the following items before merging:

Files matching src/**/*.cpp:

• Are possibly unused includes removed?

This is an automatically generated QA checklist based on modified files.

[gzotti]

Time panel seems to stop at ±100000. Time proceeds further. Not sure how you display -167785.

[Atque]

Time panel seems to stop at ±100000. Time proceeds further. Not sure how you display -167785.

Hm, really? For me it works well until the limit of 200,000. Did you build the latest commit, with the .ui file included?

[gzotti]

Ah, probably not. I just checked out once the PR appeared, and compiled. So maybe I was too early.

However, I'd like to get @henrysky 's opinion on how accurate we may think proper motion runs over ±200ka.

EDIT: See #4500 (comment)
Looks pretty good to me. That means, precession and proper motion are probably OK, planetary positions are bogus.

And you may also want to contribute a 1/2 -1 page section for Appendix F about the dangers of excessive extrapolation, and what and what not to trust in the simulation if you set the time to e.g. 170ka BP. E.g., the ELP-82b Moon has vanished into deep space, which is obvious nonsense. If you know of a planetary model to use before -13.000, please send a link.

[Atque]

Yes this is to visualize precession and proper motion. If we're almost within human visual acuity in 200,000 years for such a fast moving stars as Barnard's star, I'd say we're more than fine.

We're already clear about planetary motions being invalid past +/- 15,000 years and that the lunar motion completely breaks around 70k years into the future.

[github-actions]

Hello @Atque!

Please check the fresh version (development snapshot) of Stellarium:
https://github.com/Stellarium/stellarium-data/releases/tag/weekly-snapshot

[github-actions]

Hello @Atque!

Please check the latest stable version of Stellarium:
https://github.com/Stellarium/stellarium/releases/latest