Pi Ursae Majoris
Encyclopedia
The Bayer designation
Bayer designation
A Bayer designation is a stellar designation in which a specific star is identified by a Greek letter, followed by the genitive form of its parent constellation's Latin name...

 Pi Ursae Majoris (π UMa, π Ursae Majoris) is shared by two star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...

s in the constellation
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

 Ursa Major
Ursa Major
Ursa Major , also known as the Great Bear, is a constellation visible throughout the year in most of the northern hemisphere. It can best be seen in April...

:
  • Pi¹ Ursae Majoris (3 Ursae Majoris)
  • Pi² Ursae Majoris (4 Ursae Majoris)


They are separated by 0.70° in the sky. They are sometimes given the name Muscida, which can also refer to ο Ursae Majoris
Omicron Ursae Majoris
Omicron Ursae Majoris is a star system in the constellation Ursa Major. It is approximately 184 light years from Earth. It has the traditional name Muscida, which it shares with the optical double star Pi Ursae Majoris....

.

The two stars, Pi¹ and Pi² together, are considered an optical double star
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...

. They are not a binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...

, in that they are not gravitationally linked, but they are close to each other as seen in the sky, and so are optically associated.
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