If you visit the Campo de' Fiori (Field of Flowers) in Rome, you won't be able to miss the statue in the middle of the square (which, by the way, was still a meadow when it received its name in the Middle Ages). The statue is of Giordano Bruno, who was burned at the stake there. He was convicted on today's date in 1600 and executed nine days later.
Bruno commonly is called a "martyr for science" because he endorsed the same Copernican theory that, through injudiciousness in discussing it, resulted in Galileo living out his days under house arrest. But not so—or, at least, not relevant. Bruno didn't go to his death for his scientific views but for his theological heresies.
In the introduction to the scholarly edition of Bruno's work Cause, Principle, and Unity, Alfonso Ingegno remarked that Bruno's philosophy "calls into question the truth-value of the whole of Christianity, and claims that Christ perpetrated a deceit on mankind."
Another scholar, Frances Yates, has written that "the Church was . . . perfectly within its rights if it included philosophical points in its condemnation of Bruno’s heresies" because "the philosophical points were quite inseparable from the heresies."
Sheila Rabin, writing in the Stanford Encyclopedia of Philosophy, said that "in 1600 there was no official Catholic position on the Copernican system, and it was certainly not a heresy. When [Bruno] was burned at the stake as a heretic, it had nothing to do with his writings in support of Copernican cosmology."
By the way, the statue of Bruno was erected in 1889. The sculptor was a grand master in the Masonic order. The statue had been commissioned as a response to Pope Leo XIII's 1884 encyclical Humanum Genus, which condemned Masonry, because Bruno was understood to be a pantheist and the statue would be a poke at the pope.