The event resists a simple end-of-science narrative

The Chinese state maintained specialist observers whose reports allow later researchers to date short-lived celestial events.

What observers described as a new star is now understood as the explosive end of a massive star.

The conquest devastated a city central to centuries of astronomical, mathematical and medical scholarship.

Manuscripts and scholars continued work in Maragha, Damascus, Cairo, Central Asia and other centers.

The conquest redirected resources and personnel, contributing to new observatory projects under Mongol rule.

Tycho Brahe saw a brilliant new object in Cassiopeia; it was later identified as the supernova SN 1572.

The bright star-like object stood in a familiar constellation, challenging beliefs that the distant heavens never changed.

Tycho's subsequent careful measurements tracked the object's position and brightness; the first sighting was on this date.

The appearance of SN 1572 opened new arguments about celestial change; its physical interpretation came centuries later.

Johannes Kepler observed the bright new star of 1604 in the constellation Ophiuchus.