On finding Polaris

[Richard5]

I recently learned of another way to find the north star. A line drawn from Procyon in the constellation Canis Minor, which passes between Pollux and Castor (the twin stars in the constellation Gemini) will extend exactly to Polaris.

Now, it is not difficult at all to find Polaris but I thought it neat that here is another way to nav around the heavens. This is also a way to find your way to various constellations which may be hard to find.

[charliehows]

have to try that, i never seem to be able to find the damn thing, lucky the southern cross is so easy to find...

[Talbot]

another way to find it is to reverse engineer the problem. Set the sextant up at the DR lattitude and look north.

This is a good way to do star sights, especially if you have a real star globe

[Richard5]

Yes, that is good method but it requires instruments beyond Mk.1 eyeball.

[Talbot]

If you have a smart phone, there is a very good app that uses the gps function for position and time, and the tilt part of the phone to show you exactly what planets and stars are visible in a particular part of the sky.

[cagney]

Originally Posted by charliehows

have to try that, i never seem to be able to find the damn thing, lucky the southern cross is so easy to find...

I have never been able to find the North Star in the Southern Hemisphere either ..... for some reason.

Thomas

[charliehows]

Originally Posted by cagney

I have never been able to find the North Star in the Southern Hemisphere either ..... for some reason.

Thomas

i climb up the mast...

[Richard5]

Originally Posted by Talbot

If you have a smart phone, there is a very good app that uses the gps function for position and time, and the tilt part of the phone to show you exactly what planets and stars are visible in a particular part of the sky.

I have seen that and I am amazed. That gets me to wondering how the whole cell phone GPS works. F'rinstance, when out of range of a cell tower does the GPS function work on a cell phone? I can hardly imagine millions of cell phones each make an inquiry to a satellite. A signal collated through a tower makes more sense to my puny mind.

[colemj]

The GPS is built into the phone - no cell tower necessary.

Mark

[Greg4cocokai]

The way I learned to find Polaris is by using my hand as a measurement. If you hold your arm straight out, a finger with is one degree, a fist is 5 degrees and if you extend your pinky and thumb its 10 degrees. Polaris is from the open end of Ursa Major 11 degrees out and 1 degree away from the handle. I think I got that right. It's been a while since I could see it.

The ap for the Iphone I use is "Night Sky". It's soo cool! You just point it anywhere, any time, and it shows whats there! No need for internet. I didn't even know what an Iphone or Ipad was til I got to Aus. a year ago. Been cruising Vanautu, Solomons and PNG for a couple years.

Cheers, Greg

[Pelagic]

Originally Posted by Talbot

If you have a smart phone, there is a very good app that uses the gps function for position and time, and the tilt part of the phone to show you exactly what planets and stars are visible in a particular part of the sky.

That’s “cool”….. but I think finding your Stars is the same as finding your women…. To be truly satisfying, you have to do it by yourself!

At the risk of opening myself to all kinds of jokes… I also have a star finding book called … ‘The Hand and the Fist’

[Cormorant]

Originally Posted by Richard5

That gets me to wondering how the whole cell phone GPS works. F'rinstance, when out of range of a cell tower does the GPS function work on a cell phone? I can hardly imagine millions of cell phones each make an inquiry to a satellite....

GPS units do not query the GPS satellites. They are passive only. Mostly they just need to do a lot of computations. Here's a good basic explanation How Does GPS Work? :

Each GPS satellite transmits data that indicates its location and the current time. All GPS satellites synchronize operations so that these repeating signals are transmitted at the same instant. The signals, moving at the speed of light, arrive at a GPS receiver at slightly different times because some satellites are farther away than others. The distance to the GPS satellites can be determined by estimating the amount of time it takes for their signals to reach the receiver. When the receiver estimates the distance to at least four GPS satellites, it can calculate its position in three dimensions.

[gpshephe]

Inever have trouble finding Polaris. But haven't tried it in the open ocean. Am I missing something. Halfway between the big dipper and cassiopeia .theonly bright star there.

[barnakiel]

My way:

I find Ursa Major up first then lead an imaginary line from its gamma towards Cassiopeia's beta. Right half way between them and most prominent is Ursa Minor alpha.

Finding any part of the above set-up, once one has memorised the image of the northern sky, leads to finding the polaris most of the time.

Why not work from Ursa Minor? Well, I find it difficult to tell this one against the other bodies.

(I hope I am not mixing up latin names here, I am not an astronomer).

b.

[gpshephe]

Hey Barnakiel, the only problem as I see it with that one is what if the big dipper is below the horizon. Not at 45 north, but can be at 20. Taking a sight to me would be more of a problem than finding the damn thing. One leg wrapped around the mast, Holding the sextant in one hand, holding on with the other while the seas are 10 feet.