# Need Help Quickly! Finding the distance and positions of stars

1. Mar 1, 2005

### Garret

Hello,

Well let me give a pithy description of what’s going on. There are 6 fixed stars (constellation) within a building and an observatory, which is the only place measurements of distances and positions can be calculated. Now I need to find the distance to each start using parallax methods and quadrant, etc. Also, I can only use materials prior to the 1600’s, so no lasers (Sorry Dr. Evil), plastics, lenses, etc. Then I’m supposed to plot the positions of each start with right ascension and declination. Now the problem I’m having is visually seeing how I would do this with instruments in an accurate manner. A little help on how to approach this using parallax method and other instruments/methods would be greatly appreciated. Thanks.

Regards,
Garret & Colleagues

2. Mar 1, 2005

### SpaceTiger

Staff Emeritus
Astronomers from that era used sextants and cross staffs for measuring angles:

If you can find something like a metal protractor, that would probably fit the requirements. Do I understand correctly that these are fake stars on the ceiling of a building? Cause if they're real ones, you're pretty screwed. The first stellar parallaxes weren't measured until the mid 1800s.

3. Mar 2, 2005

### Garret

First, I'd like to say thanks. Second, the stars are fake and suspended/attached to the ceiling. Though, I'm still some what confused on how to use the instruments to find distance...

4. Mar 2, 2005

### SpaceTiger

Staff Emeritus
Have you ever done that little experiment where you put up a finger and then look at it with one eye at a time, alternating? See how your finger flips back and forth across your field of view? That's because each eye is looking at it from a different angle. Try moving your finger to different distances from your eyes. Does it flip more or less when it's closer?

Think about this for a bit and hopefully you'll get some ideas for how you can measure the distance to your model stars.

NOTE: I'm not suggesting you use just your eyes. That would probably be a really difficult measurement to make, for reasons you can hopefully figure out.

Last edited: Mar 2, 2005
5. Mar 2, 2005

### Chronos

I assume you know you must take your measurements 6 months apart. The diameter of the earths orbit [1000 light seconds] then becomes the base of a triangle. You then take the angular displacement vs selected background stars at each position and calculate the other legs of the triangle.

6. Mar 2, 2005

### SpaceTiger

Staff Emeritus
I don't think that's necessary with his hanging stars.

7. Mar 2, 2005

### Chronos

Hehe, ok. Just walk to the opposite side of the room and measure the distance.