6 August

1879:On 6 August 1879, Scottish-born German astronomer Johann von Lamont died.

Von Lamont was born on 13 December 1805, and was noted for discovering in 1852 that the magnetic field of Earth fluctuates with a 10.3-year activity cycle, but did not correlate it with the period of the Sun’s sunspot cycle.

From 1 August 1840, Johann von Lamont (as director of the Royal Astronomical Observatory in Munich) started regular and permanent observations of Earth's magnetic field.

1181:On 6 August 1181, a supernova was observed by Chinese and Japanese astronomers.