Finding North from unclear sky around New Year.

 

Finding North from unclear sky around New Year.

by tonytran2015 (Melbourne, Australia).

Click here for a full, up to date ORIGINAL ARTICLE and to help fighting the stealing of readers’ traffic.

(Blog No.121).

#find North, #finding North, #direction, #by stars, #Sirius, #Canopus, #Orion-Rigel, #Capella, #New Year, #unclear sky
Around New Year there are some bright stars shining the whole night. They include Sirius, Canopus, Orion-Rigel and Capella. These four stars can be used to locate the Celestial poles in the sky and subsequently the terrestrial principal directions.

1. Celestial poles and terrestrial directions.

Sun on Celestial Sphere

Figure: The Sun, the Moon and the stars are attached to a Celestial sphere which encloses the Earth like a giant rotating cage.

To an Earth bound observer, the Earth appears to be enclosed by a large rotating spherical shell called the Celestial Sphere with all stars attached to it. This shell rotates around the Earth nearly one revolution every 24 hours. This rotation leaves unmoved only 2 points on the shell. They are called the Northern and Southern Celestial poles of the Celestial Sphere.

If an observer can locate one Celestial pole then the projection to the ground of the line from him to the pole will be along his terrestrial North South direction.

2. Locating the Northern Celestial Pole.

Orion by Samsung GN2

Figure: Photo of the Orion constellation (Photo added 2018 May 09). Northern Celestial pole is from the top direction of this photo.

An Earth bound observer in Northern hemisphere or on the tropical zone can identify the Orion constellation around New Year. The front foot of the hunter represented by this constellation is the bright star Orion-Rigel. The trailing shoulder of the hunter is the bright star Betelgeuse.

The brightest star in the sky is Sirius. The great circle arc Sirius to Capella is 70 degrees long with Betelgeuse being close to its midpoint.
Extending the great circle arc Orion-Rigel to Capella to 100 degrees long bring us practically to the Celestial North pole.

star map mercatorx1p6

Figures 1a, 1b: The Mercator maps of the sky for inhabitants of Tropical Zone. North direction is on its top. 24hr of R.A. is near the center and R.A. increases towards the left (East) of the map. The map is to be read South side up in the Southern hemisphere.

3. Locating the Southern Celestial pole.

An Earth bound observer in Southern hemisphere or on the tropical zone can identify the Orion constellation around New Year. Sirius is the brightest star in the sky and it is behind the trailing foot of the hunter.
Canopus is the next brightest star within 45 degrees of Sirius. The great circle arc Sirius to Canopus is nearly 35 degrees long. Doubling this arc bring us practically to the Southern Celestial pole.

Bright Stars 20 Plus 2

Figure 2: Table of 20 brightest +2 stars in order of appearance.
4. Visibility of these four stars.
The four stars appear on the meridional line (the North South line through the zenith of the observer) near midnight of New Year.
They appear two hours earlier for each additional calendar month after that date.
Example:
In April, they appear on the meridional line at about 24 hr – (2 hr)×(4th-1st) = 18 hr. After 18 hr they slowly move to the setting (Western) side.

RELATED SURVIVAL BLOGS (Added in December 2016)

Caution in finding North by bisector line of a horizontal watch. Posted on October 28, 2015

Finding directions and time using the Sun and a divider., posted on May 6, 2015. <<<—This is my MOST USEFUL novel technique.

wpid-dividermwp3e2c2.jpg

find North by the Sun

Finding North direction and time using the hidden Sun via the Moon . Posted on July 6, 2015

image

Finding North direction and time accurately from the horn line of the Moon. Posted on August 12, 2015. This is my novel technique.

image

Finding North direction and time using the Moon surface features. Posted on July 1, 2015.

image

, posted on

Finding North and time by stars. Posted on August 28, 2015 .

Sky map Northern 3/4 sphereSky map Southern 3/4 sphere

Finding North and time with unclear sky. Posted on October 17, 2015.

imageimage

, posted July 22, 2016

DirectionTimeByStars

Click here for my other blogs on divider43.jpgSURVIVAL

Click here go to Divider63D400 Home Page (Navigation-Survival-How To-Money).

SUBSCRIPTION: [RSS – Posts], [RSS – Comments]

MENU: [Contents][Blog Image of Contents ][Archives ] [About]

 

4 thoughts on “Finding North from unclear sky around New Year.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.