Final answer:
The celestial event that lends its name to a chain of upscale gyms is the Milky Way.
Step-by-step explanation:
The celestial event that lends its name to a chain of upscale gyms is the Milky Way. The name of the chain is a reference to the band of faint white light in the sky that stretches across the horizon, known as the Milky Way. The gyms in this chain aim to provide a luxurious and high-quality fitness experience, just like the celestial beauty of the Milky Way.
For example, one of the upscale gyms in this chain could be named 'Milky Way Fitness Center' or 'Galaxy Gym'. These gyms may offer state-of-the-art facilities, personalized training programs, and other premium features to attract health-conscious individuals.