Constellation Data

Name: CASSIOPEIA Translation: Ethiopian Queen Abbreviation: Cas Genitive: Cassiopeiae Size: 25 Regions: Circumpolar RA: 1hour Decl: +60 degrees Season: Anytime Midnight Culmination: 9 October Pages where CASSIOPEIA is discussed in Chet Raymo's 365 Starry Nights: 169,184-188

What is the Genitive form? What is Right Ascension (RA)? Is this constellation ever visible from my latitude? What is Declination? Where should I look for a constellation on a date before or after its midnight culmination? What is Midnight Culmination?

Skylore

Wife of king Cepheus, mother of Andromeda. When Cassiopeia objected to the wedding of Perseus and Andromeda, Perseus displayed the head of Medusa, which he had concealed in his travel bag. As a result, his enemies, including Cassiopeia, were turned into stone. Neptune placed Cassiopeia in the heavens, but in order to humiliate her, he arranged it so that at certain times of the years she would appear to be hanging upside down. For the story of Andromeda and Perseus, see the film "Clash of the Titans."

Description

Trace an imaginary line from the Big Bear's pointers on past Polaris. At an equal distance on the opposite side from the Big Dipper is Cassiopeia (KASS-ee-oh-PEE-uh), an ancient Queen of Ethiopia.

As she sits on her W-shaped throne she circles round and round the pole. Like the Big Dipper, Cassiopeia is circumpolar and therefore visible no matter what the season or time of night. In the fall Cassiopeia is in the shape of a W and in the Spring she is in the shape of a M.

Legend: In the constellation chart above...
• Star colors represent their spectral types (even for double stars).
• Bright star labels are yellow; significant other stars are labelled in magenta.
• The size of each star indicates its relative magnitude.
• Constellation names are light blue.
• Grid lines represent either 10 degree intervals of declination above or below the equator, or intervals of one hour (=15 degrees) of right ascension (measured along the equator).
• Messier object numbers are pink.
• Galaxies are ovals: blue if spiral, yellow if elliptical, light blue if irregular.
• Globular clusters are gold starbursts.
• Open clusters are dotted white circles.
• Planetary nebula are green diamonds.
• Bright nebula are magenta squares.
• Dark nebula are grey rectangles.
• Green x's are x-ray sources.
• Purple O's with a diagonal slash through them are quasars.

Special Stars

In 1572 a star in Cassiopeia that previously was too faint to see flared up as bright as Venus, remaining for about a year and a half, first white and then reddish in color, before fading away. Observed by many at the time, even in daylight, it has become known as Tycho's (TEE-koze) nova, after the Danish astronomer and alchemist Tycho Brahe (BRA-hee), arguably the foremost astronomer of that generation. Tycho's Star is one of only four supernovae ever observed in the Milky Way galaxy.

Table of 25 Brightest Stars.
What is apparent stellar magnitude?

Star Clusters

M52 (Galactic cluster), mag. 8.2.

M103 (Galactic cluster), mag. 6.9.

What are Star Clusters?

Discussed in these Shows

• Stars of Our Neighborhood
• Starstruck Tonight

©1997 Welcome to the Basic Celestial Phenomena web site. To provide explanations of basic observational astronomy to students, teachers, families, and visitors to planetariums these pages have been written by an ex-OBU Planetarium Director, Kerry Magruder; the OBU Natural Sciences Coordinator, Mike Keas; and some of the students who work in the OBU planetarium.

The source for the logo is not a medieval woodcut!

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