Sector Orientation

How would I go about rotating a sector so it aligns with the plane of the galaxy and one axis (I presume X) points to the galactic center?

If I understand it correctly, currently sector orientation defaults to aligning with Earth's poles and Equator, and I'm not sure where the 3rd axis aligns.


  • There's no inherent alignment of the x/y/z coordinates. So they point in any direction you define. If you have existing star maps aligned to Earth's orientation, you'd need to convert the x/y/z positions from Earth-based coordinates to the Galactic plane.

    Project Rho has a page on this that might be helpful:

  • That was what I was trying to say. I'm using the Hipparcos 5000ly dataset, and I'm fairly certain that it's aligned to Earth's orientation.

    Anyway, thank you.

  • I'm not having any luck. I can find any number of tools to convert RA/DEC to galactic coordinates, but only for single objects. What I'm trying to find out is how much and in what directions IceAceTom had to rotate his spherical grid on his "Space 100 ly AstroSyn v3 Sector File" to get it to reference "Coreward", "Rimward", "Spinward" and "Antispin." If I had to do it for individual objects over an entire sector, it would quickly get overwhelming.

  • I got hold of the author of that sector map, so maybe I'll get a comparatively easy answer. If I do, I'll post it here for anybody else who wants to be able to convert datasets from RA/DEC orientation to galactic coordinates.

  • Sounds good. I know I've seen spreadsheets in the past that do the calcs.

  • Well I haven't found one.

    I did some guesswork that gave me a pretty flat disc across the entire Orion Spur, the 0,0 mark at the edge of the spherical sector points toward Sagitarrius A*and the "North Pole" points at Coma Berenices, but I can't promise that it's more than half-ass accurate.

    That's X axis +78 degrees, Y axis -3 degrees, Z axis -55.5 degrees.

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