An overview of the North Star.

1. POLARIS

2. Introduction
Polaris. For centuries, it has been
used by navigators and explorers to find
their way as an astrological compass.
For millennia, it has been the subject of
ancient and significant mythology.
For decades, it has been studied and
researched by astronomers.
So what is it, really? In this virtual tour
of outer space, we will attempt to
answer this question, and unveil the
secrets of one of the most famous and
brightest stars in the night sky.

3. Where?
Polaris can be found in the distant Ursa Minor
constellation, and is located 434 light years
from our own solar system. To put it in
more comprehensible terms; it is more than
four quadrillion kilometers away. The reason
Polaris is of such important note is because
it is located only 0.7 degrees off our North
Pole. Although there are stars closer than that
to our North Pole, Polaris is the brightest.
Because of this vast difference in distances,
Polaris is not gravitationally tied with our
own solar system. In fact, if Polaris was closer,
it’s much more likely that we would be the ones
orbiting it; a study in 2000 showed that Polaris
was 46 times the size of our sun. It should,
however, be noted that Polaris is what is known
as a Cepheid Variable star – this means that
its luminosity can fluctuate over time.

4. What?
Polaris is a yellow-white supergiant, Compared to our own sun, Polaris is
while our own sun is considered a 1500 kelvins warmer, at around 7200K,
yellow dwarf. It’s composed almost 7.5 times heavier, and is 2200 times
entirely of hydrogen and helium, more luminous.
like all stars.
Polaris compared to many other stars, including our sun.

5. What else?
Although Polaris is incredibly brilliant and overshadowing, it isn’t the only
thing up there. Polaris A, the largest and most famous star in the Polaris solar
system, is orbited by two other stars, the closer one being Polaris AB and the farther
one being Polaris B. Polaris AB, the smallest, is a mere 18 AU away from Polaris – this
means that the closest star from Polaris is only as far as Uranus is
from our sun!
Polaris B is about 2000 AU from Polaris A. It’s larger than Polaris AB, but still not
nearly as large as A. There are no identified planets in the Polaris solar system; only
stars.

6. History of Human Study
Polaris has been used as a navigational Ursa Minor, the constellation
tool since at least the time of the ancient Greeks. where Polaris is located, has also been the
Before that, however, Polaris was not always the subject of many myths. The Greeks
North Star. believed that it was formed when a
mother and her son, who had both been
During the time of the ancient Egyptians, transformed into bears, were banished
Thuban was a more accurate representation into the sky. Ursa Minor is one of those
of the North than Polaris was – this is because bears, while Ursa Major is the other.
the axis of the Earth shifts in 26,000 year cycles,
causing the poles to realign. In another 12,000
years, Vega will become the new North Star, and
Polaris will have lost its place. 26,000 years from
now, Polaris will have re-taken its place as the
North Star.

7. Fun Facts
If you’re looking at Polaris, point one arm at it and point the other arm at the horizon. The
degrees that the angle of your arms make is close to the latitude of your current location on
Earth.
Polaris is the brightest star in the Little Dipper.
Earth isn’t the only planet with a pole star; Mars has one, as well, but it isn’t bright enough to
be useful.
Contrary to popular belief, Polaris isn’t the brightest star in the night sky, it’s just the brightest
star in the Ursa Minor constellation. Out of all the stars we can see, Polaris is the 40th
brightest.