Final answer:
Supernova remnants, such as the Vela Supernova, are examples of remnants in the observable universe that eventually become undetectable as they dissipate over time.
Step-by-step explanation:
In the context of astrophysics and the study of the observable universe, a kind of remnant that disappears from view is one associated with stellar events, such as supernova remnants. For example, the Vela Supernova Remnant, which exploded roughly 11,000 years ago, is an example of such a remnant. As the edges of this remnant collide with the interstellar medium, they heat the surrounding gas to incredibly high temperatures, detectable in various wavelengths, including X-ray. However, as the universe expands, these remnants dissipate over time and will eventually become undetectable. Moreover, the observable universe is also impacted by phenomena like dark matter, which influences the light we receive from distant objects, and cosmic background radiation, which is the afterglow of the Big Bang and offers insights into the early universe.