A log kept by Captain Theodore "Dutch" Van Kirk, the navigator of the Enola Gay, is offered at Sotheby's.

The Enola Gay was the US aircraft that dropped the first atomic bomb in the second world war. The log describes the details of the mission that killed more than 70,000 Japanese civilians in the city of Hiroshima.

It's expected to make $300,000-500,000 in the Fine Books and Manuscripts auction at Sotheby's New York on December 6.

The log is an account of the path of the Enola Gay on August 6, 1945

Van Kirk notes down the course of the bomber on the morning of August 6, 1945.

The Enola Gay took off from Tinian Island, in the Pacific Ocean - around 2,500 miles from Hiroshima, at 2:45 AM.

Sotheby's notes: "At 0915½ (30 seconds past 8:15am Hiroshima local time) in the position field Van Kirk notes the action that would end the war and change the world forever, 'Bomb Away', further writing in the remarks field 'Circle E of Target.'

"By 0931 they were flying over Mishima, and just past 29° 43' E 137° 03' E, a little over an hour and a half later, Van Kirk notes '10:52 - Cloud Gone'."

Van Kirk, who died in 2014, said in a 2005 interview with TIME magazine: "You fight a war to win. There were over 100 numbered military targets within the city of Hiroshima.

"It wasn't a matter of going up there and dropping it on the city and killing people.

"It was destroying military targets in the city of Hiroshima — the most important of which was the army headquarters charged with the defense of Japan in event of invasion."

Enola Gay pilot Paul Tibbet's flight log sold for $86,500 in New York in 2014.

The present lot carries a higher valuation as it focuses solely on the bombing of Hiroshima, giving a minute by minute account of the attack.

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