|Designation|| SN 1572|
|Right ascension||00h 25m 18s|
|Type of object||Supernova remnant|
|Magnitude||Apparent Mag: -4 (peak)|
|Distance from Earth||3,500 ly|
Tycho's Supernova (SN 1572, B Cassiopeiae) was a supernova that occurred in the constellation of Cassiopeia. Occurring in 1572, it was one of the earliest supernovae recorded in the Milky Way. It is named after Tycho Brahe who noticed a bright star where there had been none previously on the night sky. It reached a peak magnitude of -4, making it a similar brightness to the planet Venus.
The supernova is named after Tycho Brahe who observed a star that he did not recognise near the zenith while walking home on November 11, 1572. However he was not the first person to see the supernova; some claim to have seen it in August but W. Schuler saw it a week earlier than Tycho on November 5, 1572. Initially it was the same brightness as Jupiter but quickly reached the same brightness as Venus, and could be observed during the day for around 2 weeks. It began to fade at the end of November and also became redder. After 16 months was no longer visible to the naked eye after March 1574.
Tycho's observation of the supernova ultimately lead to his life long interest in astronomy. He performed precise measurements to demonstrate that it was not a nearby object such as a comet but significantly further away, comparable to the distances of stars. Much later in the 1960s, extraordinarily faint nebulosity was discovered in the position Tycho recorded the supernova as being. This was taken to be the remnant of the supernova. No stellar remnant has been seen. In 2008 it was shown to be a Type Ia supernova.
Properties and Structure
The nebula is around 3,500 light years away and is 3.7 arcminutes across. The nebula contains a radio source catalogued as 3C 10 and also an x-ray source. The gas of the nebula is expanding extremely rapidly at some 9,000 km/s. This is much faster than other nebulae such as the Crab Nebula which is expanding at only 1,000 km/s. Infrared images have shown the shockwave produced by the supernova has heated dust.