Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 16-05-2013, 23:57   #1
Registered User

Join Date: Aug 2012
Posts: 959
On finding Polaris

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.
__________________

__________________
Richard5 is offline   Reply With Quote
Old 17-05-2013, 03:04   #2
Registered User

Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,021
Images: 3
Re: On finding Polaris

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

__________________
charliehows is offline   Reply With Quote
Old 17-05-2013, 05:25   #3
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
Re: On finding Polaris

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


__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 18-05-2013, 00:40   #4
Registered User

Join Date: Aug 2012
Posts: 959
Re: On finding Polaris

Yes, that is good method but it requires instruments beyond Mk.1 eyeball.
__________________
Richard5 is offline   Reply With Quote
Old 18-05-2013, 02:12   #5
Senior Cruiser
 
Talbot's Avatar

Cruisers Forum Supporter

Join Date: Jun 2004
Location: Brighton, UK
Boat: Privilege 37
Posts: 3,579
Images: 32
Re: On finding Polaris

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.
__________________
"Be wary of strong drink. It can make you shoot at tax collectors - and miss."
Robert A Heinlein
Talbot is offline   Reply With Quote
Old 18-05-2013, 02:25   #6
Registered User

Join Date: Dec 2005
Location: WNA
Boat: Dufour 35
Posts: 3,247
Re: On finding Polaris

Quote:
Originally Posted by charliehows View Post
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
__________________
cagney is offline   Reply With Quote
Old 18-05-2013, 02:50   #7
Registered User

Join Date: Aug 2010
Location: sydney, australia
Boat: 38 roberts ketch
Posts: 1,021
Images: 3
Re: On finding Polaris

Quote:
Originally Posted by cagney View Post
I have never been able to find the North Star in the Southern Hemisphere either ..... for some reason.

Thomas
i climb up the mast...
__________________
charliehows is offline   Reply With Quote
Old 18-05-2013, 03:30   #8
Registered User

Join Date: Aug 2012
Posts: 959
Re: On finding Polaris

Quote:
Originally Posted by Talbot View Post
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.
__________________
Richard5 is offline   Reply With Quote
Old 18-05-2013, 06:56   #9
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
Re: On finding Polaris

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

Mark
__________________
www.svreach.com

You do not need a parachute to skydive. You only need a parachute to skydive twice.
colemj is offline   Reply With Quote
Old 18-05-2013, 07:55   #10
Registered User
 
Greg4cocokai's Avatar

Join Date: Jun 2011
Location: Long Beach, Ca. USA
Boat: Norseman 447
Posts: 294
Re: On finding Polaris

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
__________________
GREG, s/v Sirena
currently, Long Beach, Ca.
Greg4cocokai is online now   Reply With Quote
Old 18-05-2013, 08:09   #11
CF Adviser
 
Pelagic's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Boat: Van Helleman Schooner 65ft StarGazer
Posts: 6,880
Re: On finding Polaris

Quote:
Originally Posted by Talbot View Post
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’
__________________
Pelagic is offline   Reply With Quote
Old 18-05-2013, 08:28   #12
Registered User
 
Cormorant's Avatar

Join Date: Jan 2009
Location: Catskill Mountains when not cruising
Boat: 31' homebuilt Michalak-designed Cormorant "Sea Fever"
Posts: 2,072
Re: On finding Polaris

Quote:
Originally Posted by Richard5 View Post
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.
__________________
Cormorant is offline   Reply With Quote
Old 26-05-2013, 07:38   #13
Registered User

Join Date: Nov 2010
Location: San Francisco Bay
Boat: Hunter Legend 40
Posts: 291
Re: On finding Polaris

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.
__________________
Gary

I'm wet nurse to a last place dead to the neck up ball club and I'm choking to death.
gpshephe is offline   Reply With Quote
Old 26-05-2013, 07:56   #14
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,314
Re: On finding Polaris

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.
__________________
barnakiel is offline   Reply With Quote
Old 26-05-2013, 09:43   #15
Registered User

Join Date: Nov 2010
Location: San Francisco Bay
Boat: Hunter Legend 40
Posts: 291
Re: On finding Polaris

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.
__________________

__________________
Gary

I'm wet nurse to a last place dead to the neck up ball club and I'm choking to death.
gpshephe is offline   Reply With Quote
Reply

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 13:01.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.