Ideas for AstroCalc

[Atque]

A few ideas of interesting calculations that could be added to the AstroCalc module:

• [ ] Extreme declination of planet
• [ ] Closest approach/furthest from Earth
• [x] Perihelion/aphelion
• [ ] Perigee/apogee
• [x] Closest approach between two objects of choice, e.g. Venus and Regulus, Jupiter and Aldebaran, Mercury and Pluto. For planets, this could be extended to also include closest true distance. Possibly add lunar occultations.

The calculations today are sometimes awkward and take too long to compute over long periods of time.

[github-actions[bot]]

Hello @Atque!

Thank you for this suggestion.

[alex-w]

Perihelion/aphelion implemented already

[alex-w]

The latest one item of list by the fact implemented too - please use the "Latest selected object" in dropdown menu, select some star and run computation.

[Atque]

Ah neat!

[gzotti]

re "awkward, takes long time". Yes, some are ill-suited to expect to be fast when there is only iterative search (bisection of possible intervals or such) possible. Sometimes there is better-suited software already available. (e.g., Occult for occultations.) Code inspection & working improvements more than welcome. I am sure some repetitive code can be avoided.

[Atque]

re "awkward, takes long time". Yes, some are ill-suited to expect to be fast when there is only iterative search (bisection of possible intervals or such) possible. Sometimes there is better-suited software already available. (e.g., Occult for occultations.) Code inspection & working improvements more than welcome. I am sure some repetitive code can be avoided.

I tried SkyMap by Chris Marriott (sadly discontinued and closed-source), and it makes some really fast calculations, e.g. extreme declination of Venus over one millennium in about 2 minutes with 8% CPU load (although the program is unresponsive while doing this). So yes, it should be possible to do this more efficiently.

[gzotti]

8% CPU load most likely means one core busy. Now, I think it's not meaningful to wait for 2 minutes while the program appears frozen. When you have other programs that do the job, please use them. Stellarium can then illustrate what has been found.

A fully new concept would be triggering "background jobs" which return some permanent data file after a while, while the user can do something else in the foreground. And of course some reader/data inspector module would then be able to deal with the contents of that data file. I know e.g. GIS applications have that. But who has time and is willing to implement such feature on his weekends or vacations when there is already software for such rarely used tasks? Feel invited to contribute in code, we all add what we need ourselves. Seriously, https://github.com/Stellarium/stellarium/wiki/FAQ#why-dont-you-implement. First, we should get some bugs fixed.