Ptolemy Cluster
E472719
The Ptolemy Cluster is a bright open star cluster in the constellation Scorpius, easily visible to the naked eye and popular with amateur astronomers.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Ptolemy Cluster canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4835400 — 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: Ptolemy Cluster Context triple: [Scorpius, containsDeepSkyObject, Ptolemy Cluster]
-
A.
Virgo Cluster
The Virgo Cluster is a massive, nearby galaxy cluster that serves as the central, dominant concentration of galaxies in our local region of the universe.
-
B.
Centaurus Cluster
The Centaurus Cluster is a massive, nearby galaxy cluster in the constellation Centaurus, notable for its rich population of galaxies and role as a major mass concentration within the local universe.
-
C.
Shapley Supercluster
The Shapley Supercluster is one of the most massive known concentrations of galaxies in the nearby universe, exerting a significant gravitational influence on surrounding cosmic structures.
-
D.
Perseus–Pisces Supercluster
The Perseus–Pisces Supercluster is a massive, elongated concentration of galaxy clusters stretching hundreds of millions of light-years across space and forming one of the most prominent large-scale structures in the nearby universe.
-
E.
Great Hercules Cluster
The Great Hercules Cluster is a bright, densely packed globular star cluster in the constellation Hercules, visible in small telescopes and one of the most prominent such clusters in the northern sky.
- 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: Ptolemy Cluster Target entity description: The Ptolemy Cluster is a bright open star cluster in the constellation Scorpius, easily visible to the naked eye and popular with amateur astronomers.
-
A.
Virgo Cluster
The Virgo Cluster is a massive, nearby galaxy cluster that serves as the central, dominant concentration of galaxies in our local region of the universe.
-
B.
Centaurus Cluster
The Centaurus Cluster is a massive, nearby galaxy cluster in the constellation Centaurus, notable for its rich population of galaxies and role as a major mass concentration within the local universe.
-
C.
Shapley Supercluster
The Shapley Supercluster is one of the most massive known concentrations of galaxies in the nearby universe, exerting a significant gravitational influence on surrounding cosmic structures.
-
D.
Perseus–Pisces Supercluster
The Perseus–Pisces Supercluster is a massive, elongated concentration of galaxy clusters stretching hundreds of millions of light-years across space and forming one of the most prominent large-scale structures in the nearby universe.
-
E.
Great Hercules Cluster
The Great Hercules Cluster is a bright, densely packed globular star cluster in the constellation Hercules, visible in small telescopes and one of the most prominent such clusters in the northern sky.
- F. None of above. chosen
Statements (43)
| Predicate | Object |
|---|---|
| instanceOf |
Messier object
ⓘ
NGC object ⓘ deep-sky object ⓘ open star cluster ⓘ |
| age | about 200 million years ⓘ |
| angularSize | 80 arcminutes ⓘ |
| apparentMagnitudeV | 3.3 ⓘ |
| appearsAs | large, rich star field ⓘ |
| approximateNumberOfStars |
80
ⓘ
up to 100 ⓘ |
| bestSeenFrom | southern hemisphere ⓘ |
| bestSeenInMonth | July ⓘ |
| cataloguedIn |
Messier Catalogue
ⓘ
linked to:
Messier catalogue
New General Catalogue ⓘ |
| containsStarType |
A-type main-sequence stars
ⓘ
B-type main-sequence stars ⓘ giant stars ⓘ |
| declination | −34° 49′ ⓘ |
| discoveredBy |
Claudius Ptolemy
ⓘ
linked to:
Claudius Ptolemaeus
|
| discoveryNote | described by Ptolemy as a nebulous object near the stinger of Scorpius ⓘ |
| distanceFromEarth |
about 300 parsecs
ⓘ
about 980 light-years ⓘ |
| galacticLatitude | −19.0 degrees ⓘ |
| galacticLongitude | −3.3 degrees ⓘ |
| hasColorIndexBminusV | about 0.0 ⓘ |
| hasMessierNumber | M7 ⓘ |
| hasNGCNumber | NGC 6475 ⓘ |
| liesIn |
Milky Way
ⓘ
Scorpius OB association ⓘ
linked to:
Scorpius–Centaurus OB association
|
| locatedInConstellation | Scorpius ⓘ |
| locatedNear | Galactic center direction ⓘ |
| namedAfter |
Claudius Ptolemy
ⓘ
linked to:
Claudius Ptolemaeus
|
| observedFrom | Earth ⓘ |
| observedSince | antiquity ⓘ |
| observingInstrument |
binoculars
ⓘ
small telescope ⓘ |
| otherName |
Caldwell 88
ⓘ
M7 ⓘ Messier 7 ⓘ NGC 6475 ⓘ |
| popularWith | amateur astronomers ⓘ |
| rightAscension | 17h 53m ⓘ |
| visibleToNakedEye | true ⓘ |
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: Ptolemy Cluster Description of subject: The Ptolemy Cluster is a bright open star cluster in the constellation Scorpius, easily visible to the naked eye and popular with amateur astronomers.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.