Final answer:
Pegasus is the flying horse in myths that ascended to the heavens and was immortalized as a constellation by Zeus after aiding the hero Bellerophon.
Step-by-step explanation:
The flying horse that flew up into the heavens in myths is named Pegasus. Pegasus is a figure from classical mythology that has been depicted in various works of art, including the tenth-century Veroli Casket. This mythical creature is often associated with heroes, such as Bellerophon, whom Pegasus aided in his quest to defeat the Chimera. Not only was Pegasus known for his partnership with heroes, but also for his place among the stars, as Zeus honoured him with a constellation in the night sky after his death.