The “Navigator’s Triangle”, seen from the northern hemisphere, from Wikimedia, HERE.
A
couple of weeks ago, I was reading a “Could You Survive” article written by one
of the Air Force Survival experts and he talked about using the “Navigator’s
Triangle” in the night sky to find north.
Have
you ever heard of the “Navigator’s Triangle”? I never had, and I thought, “Cool, another
way to use the stars to find north”!
So, I did what I always do, and did some research, and I found that it
wasn’t just that simple.
An excerpt from The Stars and Their Stories, 1913, by Alice Mary Matlock Griffith, page 41.
The
“Navigator’s Triangle” is also called the “Summer Triangle” and
it is an asterism, or a pattern of stars smaller than a constellation, made by
drawing lines between three of brightest stars in the night sky, each of which
are part of other constellations. Altair,
in the constellation of Aquila; Deneb, in the constellation of Cygnus (also
known as the “Northern Cross”) ; and Vega in the constellation of Lyra. The “Navigators Triangle” is an
imaginary, nearly isosceles triangle, which lies across the Milky Way.
An excerpt from The Stars and Their Stories, 1913, by Alice Mary Matlock Griffith, page 42, red lines added by the Author.
The
“Navigator’s Triangle” is visible for most of the year in north of the
equator, During the spring it is visible
in the eastern sky, early in the mornings; and on fall and winter evenings
until January, it can be seen in the west.
But during the summer, it rises in the east at sunset, is directly
overhead around midnight and sets at sunrise in the west, and this visibility
is why it is also known as the “Summer Triangle”.
This
asterism can also be seen in the mid-southern latitudes, below the equator,
where it will appear in the northern sky, above the horizon, upside down from
how it would appear in the northern hemisphere.
In the southern hemisphere it is called the “Northern Triangle”
or the “Winter Triangle”1.
From “Measuring The Sky”, by Brian Ventrudo, April 19, 2009, HERE. When fulling extending your arm, your fingers can measure degrees of distance.
To
find the “Navigator’s Triangle”, during the summer, after sunset2,
look east and locate Altair, which is to your right as you face east. Then, to the left of Altair, and up in
altitude, as you continue looking east, by about a two hand-spans (which
measure the distance from the tip of your little finger to the tip of your
thumb, when your arm is fully extended), or about 50o, you will find
Vega. Once you have found Vega, look
down and a little further to your left, about a hand-span, or 25o,
and you will find Deneb. To complete the
“Navigators Triangle”, look to your right as you continue looking east,
by about two hand-spans to return to Altair.
The “Navigator’s Triangle”, seen from the northern hemisphere, modified by the Author, the original, from Wikimedia, HERE.
Now,
before we go any further, a quick note on star maps is in order, since they can
look confusing as they are not drawn in the normal manner, with west on the
left side and with east on the right side of the map. They are drawn so that they show the sky as
it would appear if you were lying down, looking upwards, with your legs
pointing south. In that position as you
looked at the night sky, east would be to your left and west on your right.
Now
unfortunately, the “Navigator’s Triangle” cannot directly tell you where
north is, however, it can help you find the “Northern Cross” and once you
have found that, then you can find the North Star. And the good news is, that the stars of the “Navigators
Triangle” are so bright that they can be seen even in a sky polluted with
the lights of a city.
An excerpt from Earth and Sky Every Child Should Know, by J. E. Rogers, 1910, page 221.
The
“Northern Cross” is drawn by connecting Deneb, which is the tail of
Cygnus the Swan, to Sadr and then to the star Albiero to make the long pole of
the cross. Then draw a line from Gienah on
the left of the cross piece, through the star Sadr, and on to Rukh on the right,
to complete the cross piece.
The “Navigators Triangle” and the “Northern Cross”, the colored lines have been added by the Author, the original, from Wikimedia, HERE.
 |
An excerpt from Earth and Sky Every Child Should
Know, by J. E. Rogers, 1910, page 248, showing the “Navigators Triangle”
and the “Northern Cross”, the Author has added the colored lines. |
Now
that, you have found the “Northern Cross”, trace an imaginary line
through the sky from Gienah, on the left of the cross piece of the “Northern
Cross”, through Deneb, which is located at the top of the “Northern
Cross”, for about one hand-span, plus one fist or palm, or about 35o,
to find the North Star.
The “Navigators Triangle”, the “Northern Cross” and the line through Deneb to the North Star, the colored lines have been added by the Author, the original, from Wikimedia, HERE.
An excerpt from Earth and Sky Every Child Should Know, by J. E. Rogers, 1910, page 248, showing the “Navigators Triangle”, the “Northern Cross” and the line through Deneb to the North Star, the Author has added the colored lines.
So
now you know the how to use the “Navigators Triangle”, to find the “Northern
Cross” and then the North Star.
Don’t forget to come back next week and read “Could you survive? The Moon, the Stars, and the Navigators
Triangle ©”, where we will discuss what the United States Air Force survival
experts had to say about using the night sky to find your directions.
I
hope that you continue to enjoy The Woodsman’s Journal Online and look for me
on YouTube at BandanaMan Productions for other related videos, HERE. Don’t forget to follow me on both The
Woodsman’s Journal Online, HERE,
and subscribe to BandanaMan Productions on YouTube. If you have questions, as always, feel free
to leave a comment on either site. I
announce new articles on Facebook at Eric Reynolds, on Instagram at
bandanamanaproductions, and on VK at Eric Reynolds, so watch for me.
That
is all for now, and as always, until next time, Happy Trails!
Notes
1
From “Touring the Summer Triangle”, by Brian Ventrudo, July 3, 2015
2 Remember,
during the spring the “Navigator’s Triangle” is visible in the eastern
sky, early in the morning, and in the western sky on fall and winter evenings
until January. During the summer, it
rises in the east at sunset, will be directly overhead around midnight and it
will set at sunrise in the west.
Sources
“Calculating Sunset Time
With Your Fingers”, http://awesci.com/calculating-sunset-time-with-your-fingers/,
(accessed 11/27/18)
Matlock Griffith, Alice
Mary; The Stars and Their
Stories, [Henry Holt and
Company, New York, 1913], pages 11 to 13, 41 to 42 and 258,
Newquist, Susan; “Let
Your Fingers Tell Time”, July 31, 2000, https://www.backpacker.com/skills/let-your-fingers-tell-time,
(accessed 11/27/18)
Rogers, Julia Ellen; Earth
and Sky Every Child Should Know, [Doubleday, Page & Company, Garden
City, New York, 1910], page 221, https://books.google.com/books?id=0TsIAAAAIAAJ&pg=PA240&dq=stars+of+the+northern+cross&hl=en&newbks=1&newbks_redir=0&sa=X&ved=2ahUKEwi-99rj4_34AhVZD1kFHTuTDNE4FBDoAXoECAQQAg#v=onepage&q=stars%20of%20the%20northern%20cross&f=false,
accessed July 16, 2022
Ventrudo,
Brian; “Measuring The Sky”, April 19, 2009, https://oneminuteastronomer.com/860/measuring-sky/,
(accessed 11/27/18)
Ventrudo, Brian; “Touring
the Summer Triangle”, July 3, 2015, [© 2022 Mintaka Publishing Inc.], https://cosmicpursuits.com/245/touring-the-summer-triangle/,
accessed July 14, 2022
Wikimedia, " Wide-field_view_of_the_Summer_Triangle
", by NASA, ESA; https://commons.wikimedia.org/wiki/File:Wide-field_view_of_the_Summer_Triangle.jpg,
accessed July 7, 2022
Wikimedia, " Wide-field_view_of_the_Summer_Triangle
modifié", by NASA, ESA; https://commons.wikimedia.org/wiki/File:Wide-field_view_of_the_Summer_Triangle_modifi%C3%A9.jpg,
accessed July 7, 2022
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