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Star-hop to Perseid meteor radiant

The peak of the annual Perseid meteor shower is happening this weekend. Maybe you’ve already seen a Perseid or two streaking across the summer sky. If not, try looking late at night on August 12, hopefully before moonrise. More meteors should be flying closer to dawn on August 13, but then the moon’s light will be interfering. Do try to minimize the moon to optimize the Perseid meteor shower.

All in all, this should be a decent night to watch for meteors! Be sure to avoid city lights.

While out there peering into dark skies, try looking for the Perseid’s radiant point. You don’t need to find the radiant to enjoy the meteors, but it’s fun to find, and, in this case, relatively easy. First, look for the constellation Cassiopeia the Queen, which lords over the northeastern sky on August evenings. Draw an imaginary line from the star Navi through the star Ruchbah, then go about 3 times the Navi/Ruchbah distance to locate the famous Double Cluster in the constellation Perseus.

The Double Cluster nearly marks the radiant point of the Perseid meteor shower.

View larger. | The Double Cluster in Perseus, near the Perseid meteor shower radiant point. Photo by Fred Espenak. More details about the cluster and this photo.

The Double Cluster in Perseus, near the Perseid meteor shower radiant point. Photo via Fred Espenak.

The Double Cluster is more formally known as NGC 884 (Chi Persei) and NGC 869 (h Persei). Although the Double Cluster can be seen with the unaided eye in a dark country sky, the Double Clusters’ stars burst into view through binoculars.

The Double Cluster is thought to be over 7,000 light-years away from us, in the Perseus arm of the Milky Way galaxy. The sun, unlike the Double Cluster, resides within the Orion arm. Therefore, when we view the Double Cluster, we are gazing through our local spiral arm, and at the next spiral arm outward from the galactic center.

As a joke, the American astronaut Virgil Ivan Gus Grissom nicknamed the center star of this W or M-shape constellation “Navi.” Navi is Grissom’s middle name “Ivan” spelled backwards.

Bottom line: Tonight, as you watch the Perseid meteor shower, see if you can star-hop from the constellation Cassiopeia to the Double Cluster, which nearly coincides with the radiant point of the Perseid shower.

Top tips for 2017 Perseid meteor shower

Bruce McClure

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