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How to Find the Big Dipper

Thứ sáu - 26/04/2024 23:11

The Big Dipper is perhaps the most famous grouping of stars in the sky. It is part of a bigger constellation of stars called Ursa Major or the Big Bear, and it features in the legends of many cultures. It can help you with navigation and...

Table of contents

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Part 1

Part 1 of 4:

Getting in the Right Position

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Find the right spot. Position yourself in a location where there is not bright lighting. You will have a better chance of spotting the Big Dipper in an area not polluted with light.
- You also should position yourself in a spot where the northern horizon is clear.^{[1] X Research source}
- Wait until darkness falls. You aren't going to find the Big Dipper during the daytime. The best viewing time is between March and June and around 10 p.m.^{[2] X Research source}

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To find the Big Dipper, you need to look into the northern sky. Determine which direction is north using a magnetic compass or a map. Tilt your head back so that you are looking up at the sky at about a 60-degree angle.

During midsummer and autumn, the Big Dipper will be closer to the horizon, so don't look up quite so high.

If you are located north of Little Rock, Arkansas, you should be able to see the Big Dipper all night at any hour and any day of the year.^{[3] X Research source}

If you live as far north as New York or further north, the Big Dipper should never sink below the horizon. In southern locations, it can be more difficult to see the full Big Dipper in the fall, when some of its stars may be obscured.

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The season matters here. If it's spring or summer, the Big Dipper will be higher in the sky. If it's fall or winter, the Big Dipper will be closer to the horizon.^{[4] X Research source}

The saying “spring up and fall down” will help you remember where to look for the Big Dipper.

In the fall, the Big Dipper will rest on the horizon in evening. In the winter, the handle can appear to be dangling from the bowl. You will find the Big Dipper upside down in the spring and, in the summer, the bowl will lean toward the ground.

Part 2

Part 2 of 4:

Locating the Big Dipper

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The Big Dipper is shaped like a bowl and a handle. There are three stars in the Big Dipper's handle organized in a line. There are 4 stars that make up the Big Dipper's bowl (it looks like an irregular square). The entire Big Dipper looks somewhat like a kite, with the string being the handle and the bowl being the kite itself.^{[5] X Research source}

The last two stars of the Big Dipper's handle are called the pointers. They are called Dubhe and Merak. The brightest star is Alioth, which is the third star on the handle, closest to the bowl.^{[6] X Research source}

The tip of the Big Dipper's handle is called Alkaid. It is a hot star that means “the leader.” It is the third brightest star in Ursa Major and six times bigger than the sun. Mizar is next on the handle after Alkaid. It actually consists of two double stars.

Megrez is the star that connects the tail to the base of the bowl. It is the dimmest of the seven stars of the Big Dipper. Phecda is known as the “thigh of the bear.” It is located to the South of Megrez and makes up part of the bow.

Find the North Star. If you can find the North Star, you should be able to find the Big Dipper, and vice versa. The North Star is usually bright. To find it, look into the north sky up about one third of the way from the horizon to the top of the sky (which is called the zenith). The North Star is also called Polaris.^{[7] X Research source}

The Big Dipper rotates around the North Star through all of the seasons and through the night. The stars of the Big Dipper are as bright as those of the North Star. The North Star is often used for navigation because it points “true north.”
The North Star is the brightest star in the Little Dipper and the end of its handle. Trace an imaginary line from the North Star downward, and you should be able to find the two stars in the end of the Big Dipper's handle, which are called pointer stars because they point toward the Big Dipper. Polaris is about five stars farther away from the distance between the pointer stars themselves.

The Big Dipper is what is called circumpolar. This means it doesn't rise or set like the sun. Instead, it rotates around the north celestial pole.^{[8] X Research source}

Throughout the night, it rotates around the pole, counter-clockwise, bowl first. It makes a complete revolution around the pole once per sidereal day. A sidereal day is defined as four minutes shorter than the standard 24-hour day.
Thus, you can use the Big Dipper's rotations to keep track of time.

Part 3

Part 3 of 4:

Learning the Legends of the Big Dipper

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Some Native Americans saw the bowl of the Big Dipper as a bear. The stars of the handle were three warriors chasing it.^{[9] X Research source}

Other Native Americans saw the Big Dipper's bowl as the bear's flank and its handle as the bear's tail. In the United Kingdom and Ireland, the Big Dipper is called “Plough,” which derives from Nordic stargazing in which the Big Dipper was believed to be the chief god, Odin's, wagon or chariot. In Danish, they call it “Karlsvogna” or Charles wagon.

Various cultures see the Big Dipper as something different. In China, Japan, and Korea, it's a ladle. In northern England, a cleaver, in Germany and Hungary, a cart, and in the Netherlands, a saucepan. It's a salmon net in Finland and a coffin in Saudi Arabia.

Escaped American slaves found their way to freedom in the north along the Underground Railroad by being told to “follow the drinking Gourd.” Thus, the Big Dipper was used as a navigational method. The Micmacs of Canada saw the Big Dipper bowl as being a celestial bear, with the three stars of its handle being hunters chasing the bear.

Step 2 Learn the Big Dipper stars' distances from earth.

The stars that make up the Big Dipper are part of the Ursa Major Moving Cluster. The furthest star from earth, Alkaid, makes up the handle and is 210 light years from earth.^{[10] X Research source}

The other stars are Dubhe (105 light-years from earth); Phecda (90 light-years); Mizar (88 light-years); Merak (78 light-years); Alioth (68 light-years); and Megrez (63 light-years).
These starts are in motion. Thus, in about 50,000 years, the Big Dipper will no longer retain the same shape.

Part 4

Part 4 of 4:

Finding the Little Dipper and Ursa Major

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Use the North Star to find the Little Dipper. Once you've found the Big Dipper, you should be able to easily spot the little Dipper.^{[11] X Research source}

Remember that the two farthest most stars in the Big Dipper's handle point to the North Star. The North Star is the first star in the handle of the Little Dipper.

The Little Dipper is not as bright as the Big Dipper. It looks similar to the Big Dipper, though. It has a handle made up of three stars that connects to a four-star bowl. It is harder to find the Little Dipper because the stars are not as bright in it, especially if you are in a city.

Step 2 Use the Big Dipper to find Ursa Major.

The Big Dipper is what is called an asterism. That means it is a pattern of stars that is not a constellation. It is part of the constellation Ursa Major, the Big Bear.^{[12] X Research source}

The Big Dipper stars are the bear's tail and hindquarters. The Ursa Major constellation can be best seen in April at around 9 p.m. Using a drawing for reference (there are many online) should help you sketch out the rest of the stars that form the Big Bear once you find the Big Dipper.^{[13] X Research source}
Ursa Major is the third largest constellation and one of 88 official constellations.^{[14] X Research source}