Freeze ecliptic horizontally for constellation changes

[Christoph Kovacs]

I am trying to observe changes in the Orion constellation over a period of several thousand years. I could animate the changes, but the wobble of the ecliptic makes the star movements difficult to spot. Is there a way to freeze the ecliptic horizontally when focusing a particular constellation? Thx!

[Georg Zotti]

There is currently no option to use ecliptic frame. But you can use a scripting function

core.clear("galactic");

This does:

* use galactic coordinate frame (not available by other means)

* switch off zodiacal light

* switch off constellations

* some more defaults.

Create a mini script with your favourite settings to prepare your demos.

[Christoph Kovacs]

Hi Georg, may I ask something related. I've noticed that the Galactic Coordinate System, as implemented by Stellarium, ranges from -180° to +180° in longitude. This seems weird and contrary to its original definition (Galactic Coordinate System II, IAU 1958). Is there a switch somewhere to use the intended 0° - 360° definition? I've stumbled across this during my calculations which require fixing the coordinates first. Thank you!

[Alexander Wolf]

Hi!

сб, 29 янв. 2022 г. в 18:33, Christoph Kovacs <christop...@gmail.com>:

Hi Georg, may I ask something related. I've noticed that the Galactic Coordinate System, as implemented by Stellarium, ranges from -180° to +180° in longitude. This seems weird and contrary to its original definition (Galactic Coordinate System II, IAU 1958). Is there a switch somewhere to use the intended 0° - 360° definition? I've stumbled across this during my calculations which require fixing the coordinates first. Thank you!

Oops... You are right - it should be 0-360 degrees: https://academic.oup.com/mnras/article/121/2/123/2604025

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With best regards, Alexander