Looking for inverted planisphere

[AstroGary]

I'm looking for a planisphere (I'm at 30 N lat.) that correctly shows the sky above when lying flat on my table. The ones I have require you to hold them over your head to obtain the correct orientation for stars. For example, I want to be able to look down at the planisphere on the table, see that Polaris is 30 degrees above the horizon, and geographically North from me, and then look in the sky to the North, up 30 degrees, and find it. In other words, if I punched holes for all the stars on the planisphere, and put a light underneath it, it would project the correct location for stars on my ceiling. Is there such a thing? Thanks, --Gary

[Dragan]

Hey Gary,

Welcome to DSF.

Can't say I completely understand what it is you're looking for. Couldn't a standard planisphere give you what you're looking for? Even lying on a table?

[nicoscy]

Hi Gary,

This should do: http://www.amazon.com/Night-20%C2%B0-30%C2%B0N-Large-Star-Finder/dp/0961320761

A Planisphere will show you the sky exactly as you describe it, except than when you want to view South, you need to turn the Planisphere and turn your table -let's say- to face South.

But a Planisphere tries to represent a sphere (the night sky) on a 2 dimensional piece of paper.

If you want to literally have the exact views you describe, you need something like this: http://www.365astronomy.com/deep-space%C3%A2%C2%84%C2%A2-home-planetarium-projector-p-3239.html or any other home planetarium projector and there is no need to punch any holes ;-)

[AstroGary]

I realize I didn't explain it clearly :-). I have David Levy's "Guide to the Stars" planisphere, which is excellent. However, in order to match what's on the planisphere with what's in the sky, you have to hold it up over your head (with the correct N-S orientation). If I lay it on the table and look down on it, though, there is no way to get both the N-S and E-W orientations correct. I think what I want is Levy's planisphere with East and West inverted. Does this help explain my dilemma?

[nicoscy]

Explains the dilemma pretty well now. The problem being, that nobody caters to the orientation requirements that you want, although what you ask is reasonable.

Apparently lots of people have this issue (as a quick google search indicated). I was unable to find an inverted Planisphere but I am sure you already did your research on the internet as well...

Any chance you can sacrifice your Planisphere, make a mirror copy of it, have it laminated and then "assemble" it back?

[AstroGary]

Good idea. How would I go about making the mirror copy?

[Don Pensack]

The constellations on a planisphere, like the David Chandler ones, are correct in their star orientations and arrangements.
A mirror image will reverse the constellations from what you see.
If I am looking north, east is on my right, as it is on my planisphere.
If I am looking south, west is on my right, as it is on both sides of the planisphere. (Chandler's has a south-looking side without distortion).
On a one-sided planisphere, if you look south, the east on the planisphere will be on the left, which is also correct.
I see the issue if it is lying flat on a table, though, because the view extends past the zenith to the other side.

But that's all a needless complication, it seems to me, because you can simply turn the planisphere around to match the direction you're looking.
On mine, if I have N at the bottom when facing north, S at the bottom when facing south, and the same with east or west, then I can lay the planisphere down on a table and see the stars exactly as I see them looking up. You don't hold it above your head unless looking directly at the zenith. Though, if I put my finger on the zenith on the planisphere and look up, the stars are in their correct orientations so long as the planisphere direction marking corresponds to the direction my body is faced.

I think I see the issue, here. The direction markings on a planisphere are supposed to be at the bottom, not the top. They're supposed to indicate the direction you face your body, not the direction you point the planisphere. It is a use problem, here, not a problem with planispheres. To wit, N on a planisphere goes at the bottom of the planisphere when you face north--you don't lay it down on the table with the N designation on the north end of the planisphere. If you put it down on a table and make the direction markings along the edge correspond to where your body is pointed, all the stars line up, the contellations appear in their proper orientations. A mirror image wouldn't work because all the constellations would be reversed from how you see them. Another way to put it is, place the planisphere on the table with S on the north end, and N on the south end and walk around the table as you look particular directions and you will see all the stars correctly oriented as you look up to the sky.

[rmollise]

Most planetarium programs will allow you to print an all-sky chart with east and west reversed. But it's going to be a mirror image. Not sure why you'd want to do this...but you can. :lol: