Astronomy question: How do I find North by the position of the Sun or Polaris? (Or any other celestial body)?

I'm studying Land Surveying but I am having trouble understanding some of the astronomy used, such as finding my astronomical north by the position of a celestial body. Could somebody explain this to me in laymans terms? I know you have to look up the stars positions in an ephemeris, but what are all the steps you have to do?

Astronomy question: How do I find North by the position of the Sun or Polaris? (Or any other celestial body)?
If you can find Polaris, it's always due north.





As for the Sun, it always rises in the east and sets in the west. So if you can see the Sun and know what time of day it is, you can roughly determine north that way.





For surveying purposes, though, you will mostly want *exact* geographical north. To do that, there are two methods:


1. Transit method. If you can identify a bright star and have an ephemeris of its transit times, you can follow that star until the moment of transit, then fix the direction. Since stars always transit on the meridian, that direction will be either north or south (or, in the worst case, at the zenith). Polaris works best for this, since its movement during the night is so small. This method also requires that you know your geographic location.


2. Equal altitudes method. Find any bright star in the mid-southeast, an hour or two before culmination, and allow it to cross directly in the cross-hairs of your theodolite. Mark the altitude and instrumental azimuth (and instrumental azimuth will be arbitrary at this point, since you don't know true north; that's ok). Lock the theodolite in altitude. Allow the star to culminate and begin descending, which will take several hours. As the star descends, it will eventually reach the same altitude as it was when you made your first observation. When that happens, again mark the instrumental azimuth. The mean of the two marked azimuths is geographic south. All other directions can be determined from that.





EIther method can also work with the Sun instead of a star, although the Sun does change slightly in declination, which must be corrected for in the equal altitudes method.
Reply:At night, find Polaris (use the Big Dipper's bowl stars as pointers) - it is within and you are within 42 minutes of arc of the North celestial pole.





During the day, if you are in the northern hemisphere and have a watch with hands, hold the watch horizontal and point the hour hand at the sun. Bisect the angle between the hour hand and the 12 o'clock mark to get the north-south line.





There are probably a lot of other ways, but these are the easiest and don't need any charts or equipment.
Reply:You find it by Polaris the NORTH STAR
Reply:Find Polaris and look in that direction, you will be looking almost exactly north.
Reply:At night you can use the North Star (assuming you are in North America). The North Star's name is Polaris. If you are elsewhere in the world, to find North, you will have to do a little adjusting. In order to find the North Star, first find the Big Dipper (constellation Ursa Major), use the "pointer stars" in its cup, draw a line through them and the line will intersect with the North Star. The North Star is the end of the handle of the Little Dipper (constellation Ursa Minor). Here is a link to a picture:





http://www.astropix.com/HTML/C_SPRING/UR...
Reply:Find the big dipper. Looks like a pot.


On the outside edge of the pot, 2 stars (not the side touching the handle), draw a line from the bottom to the top. The bright start that line hits is polaris.





Look there...that's north. The angle that you make with it and the horizon is your latitude.





The sun...rises in the east, sets in the west. Hold your arms straight out to your side. point to the sun during the morning with your right hand before noon, and you are facing north. Point to the sun with your left hand after noon and you are facing north.
Reply:Polaris is within about 1/2 degree of true North. If you have to be super accurate, a program like "Polar Finder" will show you the position of Polaris in relation to true north for any hour of the day.


To determine true North by a solar method is very simple, absolutely accurate and requires no tool other than a stick.


We are talking stone age technology here. (If I hear one more guy with a PHD expound on TV how amazing it is that the ancient egyptians could orient the Pyramids with such accuracy in relation to true North, I am going to be sick)


Here is how it's done.:


No matter where you are located on earth, at local Noon the sun is located directly south of your location and is at it's highest point in the sky for that day!!


Put a straight stick in the ground where the sun can hit it and mark the tip of the shadow at regular intervals. The marks will get closer and closer to the stick as noon approaches and will get farther away from the stick once Noon has passed. Draw a line from the mark closest to the stick back to the stick. Bingo !! A true North-South line.


Why not just use an accurate watch and draw the line at 12:00 Noon and be done with it?


Because your watch is set for the time which is the reference line for your local time zone, it could be as much as 1/2 hour off. That's 71/2 degrees! ( 1 Hour in longitude =15 degrees, the size of a normal time zone)


The ancients were very aware of this and could locate a North-South line just as accurate as we can today.


Ancient people may not have had our modern technology, but they were not stupid !.





Adolph
Reply:sun raises in the north sets in the south .mold grow on the north side on trees.look for the north star the brightest star in the sky