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Supernova SN 1181 in the constellation Cassiopeia is observed by Chinese and Japanese astronomers and is visible for 185

Supernova SN 1181 in the constellation Cassiopeia is observed by Chinese and Japanese astronomers and is visible for 185 days to February 6, 1182

First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts.

One of only five supernovae in the Milky Way confidently identified in pre-telescopic records, it appeared in the constellation Cassiopeia and was visible and motionless against the fixed stars for 185 days. F. R. Stephenson first recognized that the 1181 AD "guest star" must be a supernova, because such a bright transient that lasts for 185 days and does not move in the sky can only be a galactic supernova.

Historical Significance

First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts.

Events Before

  1. Philip II of France (14) marries first wife Isabella of Hainault (10) at Bapaume

    Philip II (21 August 1165 – 14 July 1223), also known as Philip Augustus (French: Philippe Auguste), was King of France from 1180 to 1223.

  2. With the death of Manuel I Komnenos, the last Byzantine Emperor of the Komnenian restoration, the Byzantine Empire begin

    With the death of Manuel I Komnenos, the last Byzantine Emperor of the Komnenian restoration, the Byzantine Empire begins its terminal decline

  3. Diet of Gelnhausen; Henry the Lion deprived of the Duchy of Saxony

    Diet of Gelnhausen; Henry the Lion deprived of the Duchy of Saxony

  4. Yoritomo Minamoto leads uprising against Kiyomori Taira who installed his grandson, Emperor Antoku, to the throne

    Yoritomo Minamoto leads uprising against Kiyomori Taira who installed his grandson, Emperor Antoku, to the throne

  5. Minamoto no Yoritomo led force of 300 defeated at Battle of Ishibashiyama in Japan

    The Battle of Ishibashiyama (石橋山の戦い, Ishibashiyama no tatakai) (referred to as the Battle of Kobayakawa in the Gikeiki) was fought on August 24th, 1180 (Jishō calendar) or September 14th, 1180...

Events After

  1. The high altar of Paris cathedral Notre Dame is consecrated by Cardinal Henri de Château-Marçay and Maurice de Sully

    The high altar of Paris cathedral Notre Dame is consecrated by Cardinal Henri de Château-Marçay and Maurice de Sully

  2. Taira no Munemori and the Taira clan take young Emperor Antoku and the three sacred treasures and flee to western Japan

    Taira no Munemori and the Taira clan take young Emperor Antoku and the three sacred treasures and flee to western Japan to escape the Minamoto clan (Traditional Japanese date: 25th Day of the 7th Month of the 2nd Year of Juei)

  3. Battle of Mizushima: Japanese Taira clan defeat the Minamoto

    Battle of Mizushima: Japanese Taira clan defeat the Minamoto

  4. BC The Greeks enter Troy using the Trojan Horse (traditional date)

    The Trojan War was a legendary conflict in Greek mythology that took place around the twelfth or thirteenth century BC.

  5. BC Trojan War: Troy is sacked and burned according to calculations by Eratosthenes

    BC Trojan War: Troy is sacked and burned according to calculations by Eratosthenes

More from the 1180s

Henry VI, the son and heir of the Holy Roman Emperor Frederick I Barbarossa, weds Constance of Sicily

Henry VI, the son and heir of the Holy Roman Emperor Frederick I Barbarossa, weds Constance of Sicily

BC The Greeks enter Troy using the Trojan Horse (traditional date)

The Trojan War was a legendary conflict in Greek mythology that took place around the twelfth or thirteenth century BC.

Philip II of France (14) marries first wife Isabella of Hainault (10) at Bapaume

Philip II (21 August 1165 – 14 July 1223), also known as Philip Augustus (French: Philippe Auguste), was King of France from 1180 to 1223.

Holy Roman Emperor Frederick I Barbarossa and 100,000 crusaders depart Regensburg for the Third Crusade

The Third Crusade (1189–1192) was an attempt led by King Philip II of France, King Richard I of England, and Emperor Frederick Barbarossa to reconquer the Holy Land following the capture of Jerusalem...

Frequently Asked Questions

What happened on August 6, 1181?
First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts. One of only five supernovae in the Milky Way confidently identified in pre-telescopic records, it appeared in the constellation Cassiopeia and was visible and motionless against the fixed stars for 185 days. F.
Why is Supernova SN 1181 in the constellation Cassiopeia is observed by Chinese and ... significant?
First observed between August 4 and August 6, 1181, Chinese and Japanese astronomers recorded the supernova now known as SN 1181 in eight separate texts.

Explore More

August 6 in HistoryYear 1181