Hale and Bopp, who separately discovered Comet Hale-Bopp in 1995 before it became visible to the naked eye, each died at 68 years old, 8 years apart.

Alan Hale: Best known for co-discovering Comet Hale-Bopp in 1995, he passed away in 2026 at age 68. His cause of death may be linked to complications from a recent surgery.

https://en.wikipedia.org/wiki/Alan_Hale_(astronomer)

Thomas Bopp: The co-discoverer of Comet Hale-Bopp alongside Alan Hale. He died in 2018 at the age of 68 due to liver cancer.

https://ui.adsabs.harvard.edu/abs/2018JALPO..60c..23H/abstract

Alan Hale and Thomas Bopp discovered Comet Hale–Bopp separately on July 23, 1995, before it became visible to the naked eye. It is difficult to predict the maximum brightness of new comets with any degree of certainty, but Hale–Bopp exceeded most predictions when it passed perihelion on April 1, 1997, reaching about magnitude −1.8. Its massive nucleus size made it visible to the naked eye for a record 18 months. This is twice as long as the Great Comet of 1811, the previous record holder. Accordingly, Hale–Bopp was dubbed the Great Comet of 1997.

https://en.wikipedia.org/wiki/Comet_Hale%E2%80%93Bopp