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When did Tycho Brahe observe the new star in Cassiopeia?

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Painting of Danish astronomer Tycho Brahe wearing a black robe with a white ruffled collar and a gold chain necklace with a large pendant. — Tycho Brahe Tycho Brahe.

The Danish astronomer Tycho Brahe first observed the "new star" in the constellation Cassiopeia on November 11, 1572.12

Known as Tycho’s Nova, this supernova was a significant discovery that challenged the prevailing Aristotelian doctrine of the time, which held that the heavens were perfect and unchanging. By demonstrating through precise measurements that the object was located beyond the Moon in the realm of the fixed stars, Tycho provided evidence that real changes could occur in the universe.12