Sun (Friendship is Magic)

The Sun is a large star located in the Solar System somewhere in the galaxy.

History
The sun is controlled by Princess Celestia, though in ancient history, it was moved by a Council of Unicorns with the help of Starswirl the Bearded. The sun is a powerful symbol, through Celestia, the sun is almost seen as a mythological entity rather than just a celestial body. A few holidays revolve around the sun, such as the Summer Sun Celebration and likewise, many traditions and legends revolve around the sun, such as the Legend of the Rainbow Crow

Symbolism
While the symbolism of the moon has often swayed from dreamlike qualities to more strict and orderly rulership, the sun has usually come to represent gentleness, playfulness, kindness and motherly love. No doubt due to Celestia showing off all these qualities in her daily life. To some, however, the sun has been received as a darker symbol of authoritarianism and ruthlessness, such as Discord who believed Celestia was a cruel monarch who banished any she did not care, such as she did with him and Luna.

Fan theories
Some fans have went the extra mile and assume the ponies of Equestria perform some level of "sun worship".