I Any Galaxy (Milky-way) based coordinate systems?

[vsrawat]

TL;DR Summary

As the Sun also moves, how to find its absolute coordinates in the galaxy?

There is an "Ecliptic coordinate system" that represents the apparent positions, orbits, and pole orientations of Solar System objects.

But, the Sun itself is NOT having a fixed immovable positon:
- It moves around the barrycenter of the solar system
- It also revolves around the central black hole of our Milky Way galaxy.

Is there any Milky-way-based coordinate system that gives the position of the Sun/ other solar system bodies at any particualr time?

Is there any site/ software showing pictorial representation of such a "Milky-way-based" movements of solar system bodies?

Thanks.

 

[Baluncore]

Welcome to PF.

Galactic coordinates.
https://en.wikipedia.org/wiki/Galactic_coordinate_system

There is software available to translate to and from GC. An old example is:
https://en.wikipedia.org/wiki/Starlink_Project

 

[berkeman]

Galactic coordinates.
https://en.wikipedia.org/wiki/Galactic_coordinate_system

That seems weird to me. Why is our Sun designated as the origin of that coordinate system? Shouldn't it be the center of the Milky Way Galaxy instead? Does the Equatorial Coordinate System also use the Sun as the origin?

 

[Baluncore]

A Sun centred galaxy makes it easier to calculate what the sky will look like above our heads. To us, our galaxy appears to be Sun centred.

 

[glappkaeft]

Also we know with pretty high precision where the sun is. The location of the center of the galaxy has very wide error bars (+- 0.8 kpc from Reid et al 2009, ApJ, 705, 1548) so it is pretty useless as the center for calculations.

 

[Baluncore]

The galactic equator (plane of the galaxy), celestial equator (plane of Earth rotation), and the ecliptic (plane of the Earth's orbit about the Sun), are not parallel.
https://en.wikipedia.org/wiki/Galactic_plane#/media/File:Femri_5_yr_with_ecliptic_equators.jpg

 

[sophiecentaur]

Why is our Sun designated as the origin of that coordinate system?

The frame has been chosen for convenience. After all, none of us (including JWST) are more than a million miles from the origin.

 

[Baluncore]

After all, none of us (including JWST) are more than a million miles from the origin.

But we are 97 million miles away.

 

[sophiecentaur]

But we are 97 million miles away.

I should have said "apart".
We orbit the Sun regularly so using the Earth would make it inconvenient to use Earth as an origin - a conversion would be needed for every observation. Using the Sun as origin must be the least worst choice, particularly for distances that can be measured in Parsecs (I think).