Operation Centerboard II
E351025
Operation Centerboard II was the codename for the U.S. mission that dropped the "Fat Man" atomic bomb on Nagasaki, Japan, on August 9, 1945, during World War II.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Operation Centerboard II canonical | 4 |
How this entity was disambiguated
This entity first appeared as the object of triple T3358145 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Operation Centerboard II Context triple: [509th Composite Group, mission, Operation Centerboard II]
-
A.
Operation Capital
Operation Capital was a World War II Allied offensive in Burma aimed at advancing against Japanese forces as part of the larger Burma campaign.
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B.
Operation Supercharge
Operation Supercharge was a key Allied offensive during the Second Battle of El Alamein in World War II that helped break Axis defensive lines in North Africa.
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C.
Operation Totalize
Operation Totalize was a major Allied offensive launched in August 1944 during the Normandy campaign, aimed at breaking through German defenses south of Caen using coordinated infantry, armor, and heavy bomber support.
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D.
Operation Spring Tide
Operation Spring Tide is the codename for the plans detailing the accession and early reign of King Charles III following the death of Queen Elizabeth II.
-
E.
Operation Wunderland
Operation Wunderland was a World War II German Kriegsmarine naval operation in the Arctic aimed at disrupting Soviet shipping and naval forces along the Northern Sea Route.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Operation Centerboard II Target entity description: Operation Centerboard II was the codename for the U.S. mission that dropped the "Fat Man" atomic bomb on Nagasaki, Japan, on August 9, 1945, during World War II.
-
A.
Operation Capital
Operation Capital was a World War II Allied offensive in Burma aimed at advancing against Japanese forces as part of the larger Burma campaign.
-
B.
Operation Supercharge
Operation Supercharge was a key Allied offensive during the Second Battle of El Alamein in World War II that helped break Axis defensive lines in North Africa.
-
C.
Operation Totalize
Operation Totalize was a major Allied offensive launched in August 1944 during the Normandy campaign, aimed at breaking through German defenses south of Caen using coordinated infantry, armor, and heavy bomber support.
-
D.
Operation Spring Tide
Operation Spring Tide is the codename for the plans detailing the accession and early reign of King Charles III following the death of Queen Elizabeth II.
-
E.
Operation Wunderland
Operation Wunderland was a World War II German Kriegsmarine naval operation in the Arctic aimed at disrupting Soviet shipping and naval forces along the Northern Sea Route.
- F. None of above. chosen
Statements (44)
| Predicate | Object |
|---|---|
| instanceOf |
United States military operation
ⓘ
World War II operation ⓘ military operation ⓘ |
| aircraftUsed | B-29 Superfortress ⓘ |
| belligerent |
United States of America
ⓘ
surface form:
United States
|
| bombNickname | Fat Man ⓘ |
| bombType | Mark III nuclear bomb ⓘ |
| casualtiesEstimate | tens of thousands killed ⓘ |
| cityBombed | Nagasaki ⓘ |
| codenameFor | atomic bombing of Nagasaki ⓘ |
| commander | Charles W. Sweeney NERFINISHED ⓘ |
| commandStructure | Twentieth Air Force ⓘ |
| conductedBy |
509th Composite Group
ⓘ
United States Army Air Forces ⓘ |
| conflict | World War II ⓘ |
| countryOfOrigin |
United States of America
ⓘ
surface form:
United States
|
| date | 1945-08-09 ⓘ |
| day | 9 ⓘ |
| deliveryMethod | air-dropped nuclear bomb ⓘ |
| followedBy |
Japanese surrender
ⓘ
end of World War II in the Pacific ⓘ |
| historicalSignificance | second use of a nuclear weapon in war ⓘ |
| launchAircraft | Bockscar ⓘ |
| launchBase | North Field, Tinian ⓘ |
| location |
Nagasaki
ⓘ
surface form:
Nagasaki, Kyushu, Japan
|
| month | August ⓘ |
| nuclearWeaponProgram | Manhattan Project ⓘ |
| objective | force Japanese surrender ⓘ |
| operationNature | strategic bombing mission ⓘ |
| operationSequence | second nuclear attack on Japan ⓘ |
| partOf |
atomic bombings of Hiroshima and Nagasaki
ⓘ
surface form:
atomic bombings of Japan
|
| precededBy |
Operation Centerboard I
ⓘ
atomic bombing of Hiroshima ⓘ |
| region | Japanese home islands ⓘ |
| result |
contributed to Japan's decision to surrender
ⓘ
destruction of large parts of Nagasaki ⓘ |
| target | Nagasaki ⓘ |
| targetCountry | Japan ⓘ |
| theater | Pacific War ⓘ |
| timePeriod | final days of World War II ⓘ |
| weaponType | plutonium implosion-type nuclear weapon ⓘ |
| weaponUsed | Fat Man ⓘ |
| weaponYield | approximately 21 kilotons of TNT ⓘ |
| year | 1945 ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Operation Centerboard II Description of subject: Operation Centerboard II was the codename for the U.S. mission that dropped the "Fat Man" atomic bomb on Nagasaki, Japan, on August 9, 1945, during World War II.
Referenced by (4)
Full triples — surface form annotated when it differs from this entity's canonical label.