Stellarium

Geocentric Coordinates?

Asked by Jon Seamans

I haven't yet found a definitive answer regarding a few questions about viewing geocentric coordinates. I've just noticed that for closer objects (e.g. Moon and Sun), the coordinates change when I change locations. The test is a simple one: Select the Sun or Moon, click arbitrary locations on the location map. You'll see these coordinates change.

Questions have also arose in the past regarding Vernal Equinox timing accuracy. To asses this, the geocentric coordinates for the Sun must be used.

For the Vernal Equinox example, I believe I can simulate the geocentric case by setting the location to 0° Long and 0° Lat, but I'm not aware of a "Geocentric" setting within Stellarium

Is there a way to view geocentric coordinates without simulating the condition?

Edit: The Vernal Equinox occurs when the Sun crosses the Earth's equator, but not necessarily 0° Long. So setting the location to 0° Long is not a valid simulation.

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Jon Seamans (silvy5) said : 		#1

Alexander,
I discovered the interesting discussion thread about the 2014 AE timing. I think an AE / VE timing error has come up at least once before.
http://ehc.ac/p/stellarium/discussion/278769/thread/4ee10fea/#82bc/9843

Anyway, you suggested implementing a toggle for Geocentric or Topocentric Coordinates. I think that's a great idea, although for precise timing data, I typically go to other ephemerides. I don't know why, but there are certain areas, e.g. equinox timings, where Stellarium is a bit off from . But don't get me wrong, Stellarium where I spend most my time, and is my number one go-to software for >90% of all the information I want.

Respectfully,
Jon

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