posted
True, I had seen it posted here, someplace, what the Galactic North Pole was in RA, but unable to find it, that adjustment will give a more proper map. What is the RA for the Galatic Core? The positions will be proper, from Sol being the 0,0,0 point, but the alignment will be off unless I come up with what the Galatic Cores RA is. Which I had not given a thought to until this thread and the other started by SIR SIG started. I am searching that out now...
------------------ Stupid bastards and religious freaks, so safe in their castle keeps...
posted
Barring the RA for the GC you could use the Galatic Long and Lat to align a few stars and align them to as close as perfect as possible, increasing accuracy.
------------------ Stupid bastards and religious freaks, so safe in their castle keeps...
posted
The page explaining how to convert to galactic coordinates. Click "next section" for the bit about adjusting from the declination plane to the galactic plane.
------------------ Teal'c: "I am a traitor to no-one." Jaffa woman: "Except your god!" Teal'c: "False god! Dead false god..." -Stargate: SG-1, "Into the Fire"
posted
Yeah, you have to use Galactic coordinates rather than celestial coordinates to have any chance of making an accurate map. This page is a good resource for galactic mapping: http://www.clark.net/pub/nyrath/starmap.html It tells how to convert celestial coords to galactic. What I actually did once was to take a clear plastic sphere and draw constellations on it I mapped out both celestial and galactic coordinates. A fun project for a rainy day.
posted
Masao: Cool. We both linked to the same site. I guess it must be good... :-)
------------------ Teal'c: "I am a traitor to no-one." Jaffa woman: "Except your god!" Teal'c: "False god! Dead false god..." -Stargate: SG-1, "Into the Fire"
posted
Well, TSN, I find your figures produce maps that look like other maps I've seen (even professionally published ones) if I just rotate 90 degrees.
Let's see: regarding only Antares, Rigel, and Deneb, use the first value for the y coordinate, the second for the x, and invert the sign on the x coordinate.
For those who are making lists, I would love to get a copy. To be most useful (to be used by my software), it should follow the following format (plain ASCII text): X,Y,Z,SYSTEM,distance,SPECTRA,Xg,Yg,Zg,distance,REMARKS and OTHER CATALOG NAMES 0,0,0,Sol,0,G2V,0.00,0.00,0.00,from Sol,"9planets,asteroids,KuiperBelt,DiaOortCloud=0.4ly;""Sun""" -7.43,2.11,0.95,Wolf 359,7.78,M5.8Ve,-1.89,-3.90,6.46,7.78,"FlareStar,dia=0.1Sol;CNLeonis,LFT750,LTT12923,Gl406,G45-20,LHS36"
To be honest, I have no idea what "Xg,Yg,Zg" means.
------------------ You're a Starfleet Officer. "Weird" is part of the job.
[This message has been edited by spyone (edited October 10, 2000).]
posted
Found some of my own help, TSN: According to www.stelar-database.com the "galactic coordinates" are: Galactic (X,Y,Z) coordinates in ly: The coordinates of this star in space, relative to our own sun, in units of light-years. The first ("x") coordinate points directly toward the center of our galaxy (which, in the Earth's night sky, is at a right ascention of 17h42m4s and a declination of -28�55'). The second ("y") coordinate points along the galactic plane in the direction of galactic rotation, at right angles to the "x" axis. The third ("z") coordinate points straight out of the plane of the galaxy, parallel to the galactic north pole, at right angles to both the "x" and "y" axes. Our sun represents the point [0, 0, 0] in this coordinate system. These coordinates are used to find the distance between any two stars, instead of just their distance from our own sun.
This means that the standard used in astronomy is to designate the x axis along what I, at least, would call the y axis. I think it makes life simpler if _I_ change (as opposed to trying to change an entire scientific community to suit my needs).
------------------ You're a Starfleet Officer. "Weird" is part of the job.
[This message has been edited by spyone (edited October 11, 2000).]
posted
The Xg, Yg, Zg is eithre the Galactic X,Y,Z or the yearly change of X, Y, Z. The yearly change of the Coords is more important than the Galactic Coords, since a star system can move in the span of say 10 years, and with the change rate you plot to go right to the system, instead of going to the old coords and then chasing after the nearest star. To get the Z,Y,Z change you would now need to figure in Galactic Radial Velocity and Parallax change, which for what I am doing is a bit much. Maybe when one of you comes up with the Warp Drive I'll work on the Navigation/Astrometrics Department.
------------------ Stupid bastards and religious freaks, so safe in their castle keeps...
posted
spyone: Yes, if you adjust those coordinates to switch the X and Y axes, as you've said, you should get approximately the values I have...
------------------ Teal'c: "I am a traitor to no-one." Jaffa woman: "Except your god!" Teal'c: "False god! Dead false god..." -Stargate: SG-1, "Into the Fire"
posted
The www.stellar-database.com site is pretty helpful. From the explanation of x that is given, that would seem to be the north on most of our galaxy maps. Sometimes though, there is some confusion of looking up at the sky or looking down at a map which causes everything to be switched right to left. For example, both Sirius and Regulus, which are southeast of Earth on maps, have negative coordinates for x and y, which would place them southwest of Earth. So maybe you have to switch x and y and change the sign of the new x?
A slight problem with galactic coordinates might be that they're based on the center of the galaxy. Since the earth is not exactly on the true equitorial plane of the galaxy, the "galactic plane" is this coordinate system is at a slight angle to the true galactic equitorial plane. By I guess that since our distance above the plane is much smaller than the distance to the galactic core that problem is too small to produce any serious errors.
Anyways, If you omit the z coordinate, you can easily produce a map looking down on the Galactic plane from the North Pole. That easier than working back from galactic longitude and latitude. (By the way, "stellar" is misspelled in the link in spyone's post and leads to nowhere).
TSN: Wendell Chung's site is pretty cool. I don't remember how I first found it. He's already made a lot of local space maps for those of us who don't want to travel too far from earth.
------------------ When you're in the Sol system, come visit the Starfleet Museum
The best way to reconcile astronomy maps with Star Trek maps, now that I understand the problem, is to take your star trek map and rotate it counter-clockwise 90 degrees. Now use the standard axes taught in geometry: The x axis runs through Earth and the center of the Galaxy, with negative numbers being towards the center of the galaxy from earth (to the left of earth), and posative numbers to the right. The y axis runs vertically on the page, positave is away from you and negative is towards you. The z axis is, of course, above and below the paper.
I can't tell what Warp9 uses the Xg,Yg,Zg for, but I kinda doubt it is Galactic Coordinates.
------------------ You're a Starfleet Officer. "Weird" is part of the job.
posted
Spyone: I don't know if only rotating counterclockwise will work. Rotating counterclockwise 90 degrees still puts stars with a negative x and y in the left lower quadrant (on standard maps). According to that site, y is in the direction of galactic rotation. Since the galaxy rotates clockwise when you look at it from above and earth is south of the core, positive y would be to the left of Earth rather than to the right. This would work and correctly put stars with -x and -y in the right lower quadrant. For example, I know that Wolf 359 is ESE of Earth on standard maps. It's x,y coords at the Stellar Database are -1.897, -3.905. Since +x is towards the core, -x is south of earth. Since +y is in the direction of galactic rotation (to the left), -y is to the right of earth. So these coordinates find a spot just where I know W359 to be: 4 to the right and 2 down. So, if you're used to having +x to the right and +y to the top, you'll have to switch x and y and change the sign of the new x (old y).
------------------ When you're in the Sol system, come visit the Starfleet Museum
[This message has been edited by Masao (edited October 12, 2000).]
posted
Actually, on the page I linked to, I think it uses a plane parellel to the real galactic plane. It even says that, to use the plane that actually runs thorugh the center of the galaxy, you can just shift the Z coordinates (add 50ly, IIRC).
------------------ Teal'c: "I am a traitor to no-one." Jaffa woman: "Except your god!" Teal'c: "False god! Dead false god..." -Stargate: SG-1, "Into the Fire"
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