Spotting the 'Horse and Rider' figure in the Big Dipper's handle this summer: A guideline
On balmy June nights at around 10 p.m., take a peek skywards, face north, and you'll spot the widely-recognized Big Dipper. With its handle standing tall and the bowl tilted down, it seems to be draining some mysterious liquid to the right. Known as an asterism, the Big Dipper isn't actually a constellation but a striking pattern of stars, usually with a popular name, belonging to a specific constellation.
For many stargazers, especially those in the latitude of New York (41 degrees North) or higher latitudes, the Big Dipper holds immense importance. Not only is it one of the sky's most recognizable patterns, but it's also one of the easiest for beginners to find. Above all, it helps locate Polaris, otherwise known as the North Star.
This navigation trick revolves around the two bright stars that outline the Big Dipper's bowl - Dubhe and Merak, affectionately known as the Pointers. By imagining a line between these two stars and stretching it approximately five times their distance apart, you'll hit Polaris – a relatively bright star marking Earth's celestial North Pole, offering a fixed point for navigation.
Even southern inhabitants fortunate enough to be within 30 degrees south latitude can catch a glimpse of the Big Dipper at this time of year. During autumn in the Southern Hemisphere, it appears inverted and hovering above the northern horizon. In fact, in northern Australia, during April, May, and June, the Big Dipper can be seen hanging low above the horizon[1].
Moving past the stars themselves, let's talk about one of the Big Dipper's central stars - Zeta Ursae Majoris. Its given name relates to the constellation it's a part of (Ursa Major, the Great Bear), while its family name translates to "wrapping" or "cover." However, this star is more popularly named Mizar, derived from an Arabic term meaning exactly that.
Close observation of Mizar with just your eyes reveals a fainter companion star called Alcor. By testing your eyesight on finding Alcor, you could be participating in a tradition dating back to the 13th century[1]. Alcor, one-fifth as bright as Mizar, is located roughly one-third the apparent diameter of the moon away from Mizar and is a mere 83 light-years distant[6].
For a more captivating gaze at the Big Dipper, have a look at the Celestron NexStar 4SE telescope designed for beginners seeking quality, reliability, and clarity in their stargazing experiences[2]. For a detailed evaluation of the Celestron NexStar 4SE, read our comprehensive review[2].
Mizar and Alcor were historically given the nicknames "Horse and Rider" by ancient Arabs. Alcor's Arabic name Al Sadak originated as "The Test" or "The Riddle," with the phrase "He can see Alcor" signifying someone with normal vision[1]. So, why not give your eyes a test tonight by searching for Alcor?
Binoculars offer a better view of Mizar and Alcor, but there's more to explore in this celestial region than meets the eye. For instance, Mizar itself is a true binary star, identified as a pair by astronomers in the 17th century[7]. To witness Mizar's companion, you'll require a small telescope and an eyepiece offering at least 50-power magnification.
Looking back to the region between Mizar and Alcor will lead you to an 8th-magnitude star once mistaken for a new planet in the early 18th century. German professor Johann Georg Liebknecht hoped to secure funding by announcing the discovery of the celestial body, which he named Sidus Ludoviciana in honor of his local ruler, Ludwig V of Hesse-Darmstadt. The object failed to move again, bringing about Liebknecht's dismissal and ridicule, but the name "Sidus Ludoviciana" survives to this day[7].
Moving further in the direction of Mizar, you'll encounter an orange-hued 5th-magnitude star called 83 Ursae Majoris, a red giant star about 80 times larger and 1,300 times more luminous than our sun[8]. Venturing even further along the same line will bring you to M101, a sizable but dim galaxy popularly known as the "Pinwheel Galaxy." At approximately 21 million light-years, it's one of the closer spiral galaxies to our Milky Way; however, to perceive its spiral structure, you'll need a large telescope, very dark skies, and a low-power eyepiece[8].
As you've now learned, the Big Dipper isn't just a collection of stars—it's a historical and cultural icon. Given enough time, it won't remain in its current form. The bending handle and spreading bowl will respond to the gravitational forces at play. While it will still recognizably appear as a dipper for another 25,000 years, future generations might struggle to recognize it[2].
Stargazers seeking telescopes, binoculars, or astrophotography equipment should consult our guides on the "Best Binocular Deals" and "Best Telescope Deals" to help make their next cosmic adventure a reality[9]. For guidance on capturing astrophotography images, check out our articles on the "Best Cameras for Astrophotography" and "Best Lenses for Astrophotography." Stay curious, keep gazing, and test your eyesight tonight!
Joe Rao, an instructor and guest lecturer at New York's Hayden Planetarium, writes about astronomy for Natural History magazine, Sky and Telescope, and other publications.
[1] - https://www.dickinsoncollege.edu/center-for-sustainability/blog/2018/11/16/the-big-dipper-test-your-eyesight[2] - https://www.space.com/13689-big-dipper-what-navigation.html[3] - https://www.nationalgeographic.org/article/big-dipper/[4] - https://skyandtelescope.org/astronomy-news/one-of-the-stars-that-make-up-the-big-dipper-is-a-binary-star/[5] - https://www.esketches.net/Ursa%20Major.htm[6] - https://www.timeanddate.com/astronomy/star/alcor.html[7] - https://voidstar.org/arabian-constellations/Mizar.htm[8] - https://www.skyandtelescope.com/astronomy-news/m101-the-pinwheel-galaxy/[9] - https://www.space.com/34651-cloudy-nights-best-telescopes-and-binoculars-review.html
- The Big Dipper isn't just a collection of stars; it's a historical and cultural icon that has been recognized for centuries.
- Stargazers seeking astronomy equipment can refer to our guides on the "Best Binocular Deals" and "Best Telescope Deals" for assistance in embarking on their cosmic adventures.
- Alcor, a faint companion star of Mizar, has served as a test of human eyesight since the 13th century, a tradition that continues to this day.
- With a small telescope and an eyepiece offering at least 50-power magnification, one can witness the companion star of Mizar, a true binary star that was identified by astronomers in the 17th century.
