Persian and Jewish scholars shape the new capital

Aryabhata gave procedures for planetary positions, eclipses and time using concise Sanskrit verse.

Aryabhata compared the daily westward movement of stars with apparent motion experienced from a moving boat.

His trigonometric methods enabled quantitative work on arcs, shadows, eclipses and celestial coordinates.

Naubakht and Masha'allah calculated an auspicious horoscope for construction of the Abbasid capital on 30 July 762.

Celestial calculation helped legitimize an imperial city and demonstrates the close historical relationship between astronomy and astrology.

The city developed institutions where Indian, Persian and Greek materials were translated, criticized and extended in Arabic.

A new star appeared around 30 April–1 May and was recorded from East Asia and the Islamic world to Europe and possibly beyond.

His description included brightness, position and atmospheric effects, providing important evidence from Arabic astronomy.

Modern astronomers identify the expanding remnant of a white-dwarf explosion thousands of light-years away.

Chinese, Japanese, Arabic and European texts show the value of comparing records written for different purposes and audiences.