Ptolemaic magnitude scale
E1022097
The Ptolemaic magnitude scale is an ancient astronomical system, originating with Claudius Ptolemy, that ranks stars by their apparent brightness in six broad classes from first (brightest) to sixth (faintest) magnitude.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Ptolemaic magnitude scale canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T13132257 — 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.
Target entity: Ptolemaic magnitude scale Context triple: [Al-Sufi's Book of Fixed Stars, uses, Ptolemaic magnitude scale]
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A.
Ptolemaic system
The Ptolemaic system is an ancient geocentric cosmological model that places Earth at the center of the universe with the Sun, Moon, and planets moving around it in complex circular paths.
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B.
Kardashev scale
The Kardashev scale is a theoretical framework that classifies civilizations by the amount of energy they can harness and use, ranging from planetary to galactic levels.
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C.
On the Sizes and Distances of the Sun and Moon
On the Sizes and Distances of the Sun and Moon is an ancient Greek astronomical treatise that presents one of the earliest known geometric attempts to quantify the relative sizes and distances of the Sun and Moon from Earth.
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D.
Titius–Bode law
The Titius–Bode law is an 18th-century empirical rule that approximates the distances of planets from the Sun using a simple numerical sequence, historically noted for roughly predicting the positions of several known planets and the asteroid belt.
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E.
Tychonic system
The Tychonic system is a historical hybrid model of the cosmos in which Earth is stationary at the center while the Sun orbits Earth and the other planets orbit the Sun, proposed as a compromise between geocentric and heliocentric theories.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
Target entity: Ptolemaic magnitude scale Target entity description: The Ptolemaic magnitude scale is an ancient astronomical system, originating with Claudius Ptolemy, that ranks stars by their apparent brightness in six broad classes from first (brightest) to sixth (faintest) magnitude.
-
A.
Ptolemaic system
The Ptolemaic system is an ancient geocentric cosmological model that places Earth at the center of the universe with the Sun, Moon, and planets moving around it in complex circular paths.
-
B.
Kardashev scale
The Kardashev scale is a theoretical framework that classifies civilizations by the amount of energy they can harness and use, ranging from planetary to galactic levels.
-
C.
On the Sizes and Distances of the Sun and Moon
On the Sizes and Distances of the Sun and Moon is an ancient Greek astronomical treatise that presents one of the earliest known geometric attempts to quantify the relative sizes and distances of the Sun and Moon from Earth.
-
D.
Titius–Bode law
The Titius–Bode law is an 18th-century empirical rule that approximates the distances of planets from the Sun using a simple numerical sequence, historically noted for roughly predicting the positions of several known planets and the asteroid belt.
-
E.
Tychonic system
The Tychonic system is a historical hybrid model of the cosmos in which Earth is stationary at the center while the Sun orbits Earth and the other planets orbit the Sun, proposed as a compromise between geocentric and heliocentric theories.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
astronomical brightness scale
ⓘ
historical astronomical system ⓘ stellar magnitude scale ⓘ |
| appliesTo | fixed stars ⓘ |
| approximateDate | circa 150 CE ⓘ |
| assumes | stars grouped into discrete brightness classes ⓘ |
| assumesObserver | average human eye under dark skies ⓘ |
| brightestClass | first magnitude ⓘ |
| catalogueAssociated | Ptolemy star catalogue NERFINISHED ⓘ |
| classificationBasis | naked-eye visual impression ⓘ |
| classificationType | visual brightness class ⓘ |
| classRangeLowerBound | 1 ⓘ |
| classRangeUpperBound | 6 ⓘ |
| comparedToModernScale | qualitative rather than quantitative ⓘ |
| dataType | ordinal scale ⓘ |
| developedBy | Claudius Ptolemy NERFINISHED ⓘ |
| documentationLanguage | Ancient Greek ⓘ |
| era | 2nd century ⓘ |
| faintestClass | sixth magnitude ⓘ |
| field |
astrometry
ⓘ
astronomy ⓘ |
| hasMagnitudeClass |
fifth magnitude
GENERATED
ⓘ
first magnitude GENERATED ⓘ fourth magnitude GENERATED ⓘ second magnitude GENERATED ⓘ sixth magnitude GENERATED ⓘ third magnitude GENERATED ⓘ |
| historicalStatus | superseded ⓘ |
| influenced |
Pogson magnitude scale
NERFINISHED
ⓘ
modern logarithmic magnitude scale ⓘ |
| limitingMagnitude | approximately sixth magnitude ⓘ |
| measures |
apparent brightness of stars
ⓘ
apparent magnitude ⓘ |
| namedAfter | Claudius Ptolemy NERFINISHED ⓘ |
| numberOfClasses | 6 ⓘ |
| observationMethod | unaided eye ⓘ |
| orderingPrinciple | smaller magnitude number indicates brighter star ⓘ |
| originatedIn | ancient Greece ⓘ |
| precision | coarse ⓘ |
| relatedConcept |
apparent magnitude
ⓘ
naked-eye limiting magnitude ⓘ visual magnitude ⓘ |
| replacedBy |
Pogson magnitude scale
ⓘ
logarithmic stellar magnitude system ⓘ |
| usedFor |
cataloguing stars
ⓘ
ranking stellar brightness ⓘ |
| usedInWork | Almagest NERFINISHED ⓘ |
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.
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.
Subject: Ptolemaic magnitude scale Description of subject: The Ptolemaic magnitude scale is an ancient astronomical system, originating with Claudius Ptolemy, that ranks stars by their apparent brightness in six broad classes from first (brightest) to sixth (faintest) magnitude.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.