Astronomers have long been intrigued by Polaris. In 1911, Danish astronomer Ejnar Hertzsprung discovered that Polaris’ primary star was variable. Then, in 1913, Hertzsprung determined distances to several variable stars using parallax. His research relied on Henrietta Leavitt’s discovery of the period-luminosity relation in 1908.
In the night sky, you can easily see the North Star, or Polaris. It is also called the North Star, as it sits more or less directly over the Earth’s north pole. To find it, look for the constellation Ursa Minor. The constellation is named for the fact that it is almost directly over the North Pole, which is 430 light years from Earth. While it’s not the brightest star in the night sky, it is easy to see, even in a city.
Ancient Greeks and Romans used Polaris as a star to navigate, but it’s not as prominent in mythology. Rather, the Pole Star is often discussed in terms of its location on the ecliptic plane. It is the peg that holds the world together. But humanity’s interest in the Pole Star is more practical. For centuries, sailors used it to guide their ships. Those interested in traveling by land could use it as their guide, and the northern limit of their positions could be determined by its position in Polaris.
Another star that’s worth observing is Polaris. This star is relatively bright compared to its neighbors, the Pointers Dubhe and Merak. It takes 23 hours and 56 minutes for the Big Dipper to complete its circle around Polaris. In addition, it’s the first star in that direction. Hence, it’s a popular destination for tourists who are unfamiliar with the night sky. However, the Pole Star may not be visible from urban areas.
During the last 3,500 years, voyaging cultures of the Pacific have relied on the stars in the sky to guide them. In fact, the stars like Polaris guided Polynesian canoes from Canada to Japan. Today, this star is still used by the Polynesian Voyaging Society to navigate the Pacific. Christopher Columbus and the Apollo astronauts also use the star to guide them to the moon. All these cultures have benefited from the star Polaris.
Because Polaris lies directly over the North Pole, it’s most visible from the northern horizon. This star is closest to the northern horizon when the observer is at the North Pole, and the latitude of New York corresponds to 41 degrees. From an observer’s perspective, this star is visible from a distance of 71 degrees. If the observer is farther south, however, the star will appear close to the northern horizon.
If you want to find Polaris with a telescope, you need to look for the constellation Ursa Minor, also known as the Little Dipper. The stars of Ursa Minor are much fainter than Polaris, and it will be easiest to find it by finding the seven stars that form the Big Dipper. The stars at the bottom of the Little Dipper point toward Polaris. So, if you’re looking for the North Star, then you’ve found the perfect place to find it.
The star Polaris is located close to the north celestial pole, which is the location of the Earth’s rotational axis. Since it’s so close to the axis of the Earth, stars near the pole appear to rotate around the night sky, while those farther away travel in larger circles. Some stars travel great distances to get to this point. For that reason, the star Polaris is a good reference for astronomers.
While most stars in the night sky aren’t exceptionally bright, Polaris is easily visible to the unaided eye. In fact, Polaris is the 48th brightest star in the sky. The star is actually a triple star system: the yellow supergiant Polaris Aa is the brightest star in the constellation, and two white main sequence stars called Alpha Ursae Minoris. Although Polaris is not the brightest star in the sky, it has been used as a reference point for navigation by early astronomers.