What contributions to modern astronomy were made by chinese and islamic astronomers during the dark ages of medieval europe?

The contributions by Chinese astronomers lie mostly

In translations of Indian astronomical books into Chinese.

Description of magnetic needle compass

Observation of supernova, now called SN 1054

Development of the algorithm and calculations to form new and improved calendars with each new dynasty.

The contributions of Islamic astronomers lie mostly in

Writing books based on their observations in observatories

Described Andromeda Galaxy

Observed the SN 1006 supernova

Explanation:

Chinese Astronomers:

Shen Kuo (1031-1095 CE) was the first astronomer to describe magnetic-needle compass.

He along with is colleague Wei Pu also measured the distance between distance between the pole star and true north for navigational purpose.

The astronomical table of sines by the Indian astronomer and mathematician Aryabhatan was translated into the Chinese astronomical and mathematical book Treatise on Astrology of the Kaiyuan Era.

The supernova that created the Crab Nebula observed in 1054, now known as the SN 1054 was observed by Chinese Astronomers.

Islamic Astronomers:

The Persian Muslim astronomer Abd al-Rahman al-Sufi in his in his Book of Fixed Stars described Andromeda Galaxy.

The Egyptian Arabic astronomer Ali ibn Ridwan and Chinese astronomers in 1006 observed The SN 1006 supernova, which is the brightest apparent magnitude stellar event in recorded history.

Some of the prominent Islamic astronomers from this period of time include Al-Battani, Thebit, Abd al-Rahman al-Sufi, Biruni, Abū Ishāq Ibrāhīm al-Zarqālī, Al-Birjandi, and the astronomers of the Maragheh and Samarkand