This obituary is part of a series about people who have died in the coronavirus pandemic. Read about others here.
Only the hottest stars shine with the searing but invisible blue-beyond-blue light called ultraviolet. When Stuart Bowyer arrived as a rangy and voluble young professor at the University of California, Berkeley, in 1968, no telescopes could see these stars in their glory.
Nor did astronomers, or the rest of humanity, know whether anybody else was Out There — whether the airwaves might be full of alien beeps and crackles from cosmic ham radio operators trying to say “Hi” or to warn with a “Watch out” about those nukes and that rising carbon dioxide.
Dr. Bowyer devoted his career to closing the cognitive gap on both counts.
At Berkeley, he led teams that sent instruments into space on balloons, sounding rockets, the space shuttle and finally his own satellite to reveal more than a thousand stars, galaxies and raging gas clouds illuminating the cosmos in a new color.
On the ground, he also pioneered the search for signals from extraterrestrial civilizations, if they were there, building Berkeley into a world center in the search for extraterrestrial intelligence, or SETI.
Dr. Bowyer died on Sept. 23 at his home in Orinda, Calif. He was 86. The university said the cause was complications of Covid-19.
His former colleagues described Dr. Bowyer as bigger than life, both in size and in spirit, a brash man you either loved or hated. “He put his whole body and soul into things,” said Dan Werthimer, the Marilyn and Watson Alberts chair and chief scientist at the Berkeley SETI Research Center.
Dr. Werthimer recalled that Dr. Bowyer and his wife, Jane Baker Bowyer, an education professor at nearby Mills College, had cultivated a Japanese garden in their backyard, “the most serene place you could imagine,” and also attended Burning Man.
Dr. Bowyer made his biggest mark with his ultraviolet studies of the universe.
Ultraviolet rays, with wavelengths shorter than visible light and longer than X-rays, are not only invisible to the eye; the more extreme short-wavelength kind are difficult to focus with conventional optics. But many important astrophysical and atomic processes involving hydrogen, the most abundant element in the universe and in stars, give off ultraviolet light.
Dr. Bowyer’s effort to extend astronomy into the missing ultraviolet zone was resisted at first. The atmosphere absorbs ultraviolet rays before they hit the ground, preventing humans from seeing the hottest stars and blazing plasmas. A view from space was required, Dr. Bowyer argued, but many astronomers thought there would still be nothing to see. The thin gas that pervades interstellar space would absorb all the ultraviolet light, they said.
But Dr. Bowyer persisted, and he proved they were wrong. A sensor that he and his team mounted on the Apollo-Soyuz, a joint U.S.-Soviet mission in 1975, detected extreme ultraviolet radiation from some dead stars known as hot white dwarfs and an exploding star called a nova.
Dr. Bowyer followed