North Star Pointer Constellation Cassiopeia Is Opposite the Big Dipper

Summary: North Star pointer constellation Cassiopeia circles Polaris oppositely from the Big Dipper all year for stargazers northward from 35 degrees north latitude.

Cassiopeia the Seated Queen's brightest star, Schedar (Alpha Cassipeiae) points to Polaris: Learn to Skywatch @Learntoskywatch, via Twitter July 22, 2016

The distinctive M/W-shaped asterism, or pattern of stars, in North Star pointer constellation Cassiopeia is a directional aid year-round as a circumpolar constellatory fixture in the Northern Hemisphere for latitudes northward from the 35th parallel.

An imaginary line extended from the peak of the acute angle formed by the asterism’s deeply notched V segment leads directly to Polaris, known popularly as the North Star. Designation as the current northern pole star recognizes the multiple star’s extreme closeness to the north celestial pole. The trio of yellow supergiant with two smaller companions marks not only the tip of the tail of Ursa Minor (Latin: “Little Bear”) but also the tip of the handle for the constellation’s seven-star asterism, the Little Dipper.

The constellation’s brightest star, Alpha Cassiopeiae (α Cassiopeiae; Alpha Cas, α Cas), marks the vertex, or endpoint where the angle’s sloping rays, or lines, meet. Alpha Cassiopeiae has the traditional name of Schedar (Arabic: şadr, “breast").

The constellation’s second brightest star, Beta Cassiopeiae (ß Cassiopeiae; Beta Cas, ß Cas), is placeholder for the open end of the outer ray. Beta Cassiopeiae is known traditionally as Caph (Arabic: kaf, “palm.

Third-brightest star Gamma Cassiopeiae (γ Cassiopeiae; Gamma Cas, γ Cas) marks the limit of the angle’s inner flank as well as the asterism’s center.

Cassiopeia’s chair circles the North Star on the opposite side from the Big Dipper. They each complete a full circle of Polaris every 23 hours 56 minutes.

The Big Dipper is an asterism composed of the seven brightest stars in the northern constellation of Ursa Major. Known popularly as the Great Bear, Ursa Major is credited with 93 stars.

Alpha Ursae Majoris (α Ursae Majoris; Alpha UMa, α UMa) and Beta Ursae Majoris (ß Ursae Majoris; Beta UMa, ß UMa) respectively mark the top and bottom of the front side of the dipper’s bowl. The two stars are known as pointer, or guard, stars because an imaginary line extended beyond Alpha UMa leads to Polaris. Known popularly as Dubhe (Arabic: dub, “bear”), Alpha UMa is the second brightest star in the Great Bear constellation. Known popularly as Merak (Arabic: al-maraqq, “loins of the bear”), Beta UMa is the constellation’s brightest star.

An imaginary clock face for their relative positions places Polaris at the center, from which the short, thick hour hand and the long, thin minute hand radiate. During their westward, or counter-clockwise, passage around Polaris, Alpha Cassiopeiae in Cassiopeia’s chair and Dubhe and Merak in the dipper’s bowl successively move through opposite points on the clock face’s periphery, where the clock’s numbers tell hours and minutes.

Cassiopeia’s chair helps to pinpoint not only north for wayfarers but also Andromeda Galaxy for stargazers. An imaginary arrow shot straight outward from a bow formed by the trio of Alpha, Beta and Gamma Cassiopeiae lands at Andromeda Galaxy.

Cassiopeia’s noticeable asterism of the constellation’s five brightest stars marks the chair in which Greek mythology’s vainglorious Ethiopian queen is doomed to sit for eternity. The asterism perches variably as an M or a W, according to season and time of day. As an M, Cassiopeia’s chair frightens the seated queen with the prospect of falling from a perch that is secure as a W.

The takeaway for Cassiopeia the Seated Queen constellation is the easy, fun and practical visibility of its five-star, M/W shaped asterism. The simple beauty of the queen’s chair is enhanced by its practical application as a finding aid for true north.

Cassiopeia the Seated Queen and Ursa Major the Great Bear circle around the Little Dipper asterism's Polaris: Alexander Korf @FarikoBrainiac, via Twitter July 31, 2014

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Cassiopeia the Seated Queen's brightest star, Schedar (Alpha Cassipeiae) points to Polaris: Learn to Skywatch (@Learntoskywatch), via Twitter July 22, 2016, @ https://twitter.com/Learntoskywatch/status/756549778654257153

Cassiopeia the Seated Queen and Ursa Major the Great Bear circle around the Little Dipper asterism's Polaris: Alexander Korf @FarikoBrainiac, via Twitter July 31, 2014, @ https://twitter.com/FarikoBrainiac/status/494908917265481728

For further information:

Alexander Korf @FarikoBrainiac. "Cassiopeia Dances with Ursus Major, Hugging Polaris." Twitter. July 31, 2014.
Available @ https://twitter.com/FarikoBrainiac/status/494908917265481728

AlfieAesthetics. “Find North with the Stars - Cassiopeia - Celestial Navigation (Northern Hemisphere).” YouTube. Aug. 30, 2014.
Available @ https://www.youtube.com/watch?v=eSRAZrrMRQI

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Available @ http://kids.britannica.com/comptons/article-9341172/Cassiopeia

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Available @ http://www.solarsystemquick.com/universe/cassiopeia-constellation.htm

EarthSky Team. “Cassiopeia and Big Dipper circle Polaris.” EarthSky Tonight. Jan. 1, 2016.
Available @ http://earthsky.org/tonight/cassiopeia-and-big-dipper

Learn to Skywatch @Learntoskywatch. "Tonight's Target: Look North. Can you find the Big Dipper, Polaris, Cepheus, and Cassiopeia?" Twitter. July 22, 2016.
Available @ https://twitter.com/Learntoskywatch/status/756549778654257153

Marriner, Derdriu. “Cassiopeia the Queen Constellation Is True Arrow to Andromeda Galaxy.” Earth and Space News. Wednesday, Aug. 24, 2016.
Available @ https://earth-and-space-news.blogspot.com/2016/08/cassiopeia-queen-constellation-true.html

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Available @ http://earthsky.org/favorite-star-patterns/big-and-little-dippers-highlight-northern-sky

McClure, Bruce. “More meteors? Plus Cassiopeia in the north.” EarthSky Tonight. Dec. 14, 2015.
Available @ http://earthsky.org/tonight/cassiopeia-high-in-the-north-on-winter-evenings

Stern, Dr. David P. “Finding the Pole Star.” NASA Goddard Space Flight Center (GSFC) International Solar Terrestrial Physics (ISTP) > Stargaze. Last updated April 23, 2008.
Available @ http://www-istp.gsfc.nasa.gov/stargaze/Spolaris.htm