Corona Borealis, the "Northern Crown," is a small yet distinct constellation in the Northern Hemisphere. It forms a semi-circular arc of stars that resembles a crown or tiara. This constellation is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations recognized today.
Key Features
- Shape: Corona Borealis is notable for its arc-shaped pattern of stars, which is easily identifiable against the night sky.
- Size: It is relatively small, ranked 73rd in size among the constellations, covering an area of about 179 square degrees.
- Brightness: The constellation is not very bright, but its distinctive shape makes it recognizable.
Mythology
In Greek mythology, Corona Borealis is associated with the story of Ariadne, the daughter of King Minos of Crete. According to the myth, Ariadne helped Theseus defeat the Minotaur and was later abandoned by him on the island of Naxos. The god Dionysus found her and, in love, placed her wedding crown in the sky as a constellation, which became Corona Borealis.
Notable Stars
- Alphecca (Alpha Coronae Borealis): The brightest star in the constellation, Alphecca is a white main-sequence star located approximately 75 light-years from Earth. It is also known as Gemma, meaning "jewel," and has a magnitude of about 2.23.
- Nusakan (Beta Coronae Borealis): The second-brightest star, Nusakan is a binary star system about 114 light-years away. Its magnitude is around 3.68.
- Theta Coronae Borealis: A third notable star, Theta Coronae Borealis, is also a binary system, with a magnitude of about 4.13.
Visibility
- Best Viewed: Corona Borealis is best seen during late spring and summer, especially in the Northern Hemisphere. The constellation reaches its highest point in the sky around midnight in June.
- Location: It lies between the constellations of Boötes to the west and Hercules to the east, and its arc of stars is quite easy to spot due to its unique shape.
Tips for Observing
- Dark Skies: Although the constellation's stars are not very bright, Corona Borealis is relatively easy to identify in areas with low light pollution.
- Use a Star Chart: A star chart can help locate Corona Borealis in relation to the nearby, brighter constellations of Boötes and Hercules.
- Binoculars or Telescope: While the main stars of Corona Borealis can be seen with the naked eye, a small telescope or binoculars can enhance the view, particularly of the binary systems like Nusakan.