Alphecca

Alphecca, also known as Alpha Coronae Borealis, is the brightest star in the constellation Corona Borealis, the Northern Crown. It is a binary star system located approximately 75 light-years away from Earth. The primary star, Alphecca A, is a white main-sequence star of spectral type A0V, with an apparent magnitude of 2.23. It is about 2.7 times more massive and 2.4 times larger than the Sun.

The secondary star, Alphecca B, is a magnitude 13.5 star that orbits Alphecca A with a period of about 17.4 days. Alphecca B is a red dwarf of spectral type M4V, which is significantly cooler and less massive than Alphecca A. The system is relatively young, with an estimated age of around 300 million years.

Alphecca is notable for its position in the sky, as it marks the tip of the Northern Crown constellation. It is also known for its rapid rotation, with a projected rotational velocity of about 240 kilometers per second at the equator. This rapid rotation causes the star to be oblate, meaning it is slightly flattened at the poles and slightly bulging at the equator.

The name Alphecca is derived from the Arabic phrase "al-fakhkhat," which means "the broken ring." This name reflects the star's position in the constellation, which resembles a broken ring or crown. The star has been known by this name since ancient times, and it continues to be a popular target for amateur astronomers and stargazers.