Cassegrain telescope design
E481876
The Cassegrain telescope design is a reflecting telescope configuration that uses a combination of a primary concave mirror and a secondary convex mirror to fold the optical path and produce a compact instrument with a long effective focal length.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Cassegrain reflecting telescope design | 1 |
| Cassegrain telescope design canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4932794 — 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: Cassegrain telescope design Context triple: [Laurent Cassegrain, notableWork, Cassegrain telescope design]
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A.
Maksutov–Cassegrain telescope design
The Maksutov–Cassegrain telescope design is a compact catadioptric optical system that uses a spherical primary mirror and a meniscus corrector lens to provide long focal lengths with well-corrected, high-contrast images in a relatively short tube.
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B.
Schmidt–Cassegrain telescope design
The Schmidt–Cassegrain telescope design is a compact catadioptric optical system that combines a spherical primary mirror with a Schmidt corrector plate to provide long focal lengths in a short, portable tube widely used in amateur and professional astronomy.
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C.
Dall–Kirkham telescope design
The Dall–Kirkham telescope design is a type of reflecting telescope that uses an elliptical primary mirror and a spherical secondary mirror to provide good on-axis image quality with relatively simple, easy-to-manufacture optics.
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D.
Schmidt telescope
A Schmidt telescope is a wide-field reflecting telescope design that uses a spherical primary mirror and a correcting lens to capture sharp images over a large area of the sky.
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E.
Wolter type I grazing-incidence telescope
A Wolter type I grazing-incidence telescope is a specialized X-ray imaging system that uses nested, shallowly angled mirror surfaces to focus high-energy X-ray photons that would otherwise penetrate or be absorbed by conventional optical mirrors.
- 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: Cassegrain telescope design Target entity description: The Cassegrain telescope design is a reflecting telescope configuration that uses a combination of a primary concave mirror and a secondary convex mirror to fold the optical path and produce a compact instrument with a long effective focal length.
-
A.
Maksutov–Cassegrain telescope design
The Maksutov–Cassegrain telescope design is a compact catadioptric optical system that uses a spherical primary mirror and a meniscus corrector lens to provide long focal lengths with well-corrected, high-contrast images in a relatively short tube.
-
B.
Schmidt–Cassegrain telescope design
The Schmidt–Cassegrain telescope design is a compact catadioptric optical system that combines a spherical primary mirror with a Schmidt corrector plate to provide long focal lengths in a short, portable tube widely used in amateur and professional astronomy.
-
C.
Dall–Kirkham telescope design
The Dall–Kirkham telescope design is a type of reflecting telescope that uses an elliptical primary mirror and a spherical secondary mirror to provide good on-axis image quality with relatively simple, easy-to-manufacture optics.
-
D.
Schmidt telescope
A Schmidt telescope is a wide-field reflecting telescope design that uses a spherical primary mirror and a correcting lens to capture sharp images over a large area of the sky.
-
E.
Wolter type I grazing-incidence telescope
A Wolter type I grazing-incidence telescope is a specialized X-ray imaging system that uses nested, shallowly angled mirror surfaces to focus high-energy X-ray photons that would otherwise penetrate or be absorbed by conventional optical mirrors.
- F. None of above. chosen
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
reflecting telescope configuration
ⓘ
telescope design ⓘ |
| hasAdvantage |
convenient eyepiece or instrument position at back of telescope
ⓘ
long focal length in compact form ⓘ short physical tube length ⓘ suitable for high magnification observations ⓘ |
| hasApplication |
astronomical observation
ⓘ
imaging systems ⓘ radio telescopes ⓘ space telescopes ⓘ spectroscopy ⓘ terrestrial observation ⓘ |
| hasDesignGoal |
improve instrument mounting convenience
ⓘ
provide long focal ratio ⓘ reduce telescope length ⓘ |
| hasFeature |
central obstruction by secondary mirror
ⓘ
hole in primary mirror for light exit ⓘ secondary mirror supported on spider or corrector plate ⓘ |
| hasFocalPlaneLocation | behind primary mirror ⓘ |
| hasHistoricalOrigin | 17th century ⓘ |
| hasLightPath | light reflects from primary to secondary to focal plane ⓘ |
| hasLimitation |
diffraction effects from central obstruction
ⓘ
more complex mirror fabrication than simple Newtonian ⓘ |
| hasOpticalConfiguration | two-mirror reflecting system ⓘ |
| hasOpticalPath | folded optical path ⓘ |
| hasPrimaryMirrorShape | concave ⓘ |
| hasPrimaryMirrorType | paraboloidal mirror ⓘ |
| hasProperty |
compact instrument form
ⓘ
long effective focal length ⓘ |
| hasSecondaryMirrorShape | convex ⓘ |
| hasSecondaryMirrorType | hyperboloidal mirror ⓘ |
| hasTypicalFocalRatioRange | f/10 to f/20 ⓘ |
| hasVariant |
Dall–Kirkham telescope
ⓘ
Maksutov–Cassegrain telescope ⓘ
linked to:
Maksutov telescope
Ritchey–Chrétien telescope ⓘ
linked to:
Ritchey–Chrétien reflector
Schmidt–Cassegrain telescope ⓘ
linked to:
Schmidt–Cassegrain telescope design
classical Cassegrain telescope ⓘ |
| isCommonIn | compact high-magnification telescopes ⓘ |
| isSubclassOf | catadioptric and reflecting telescope families via variants ⓘ |
| isUsedBy |
amateur astronomers
ⓘ
professional observatories ⓘ space agencies ⓘ |
| namedAfter | Laurent Cassegrain ⓘ |
| supportsMounting |
cameras at Cassegrain focus
ⓘ
photometers at Cassegrain focus ⓘ spectrographs at Cassegrain focus ⓘ |
| uses |
primary concave mirror
ⓘ
secondary convex mirror ⓘ |
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: Cassegrain telescope design Description of subject: The Cassegrain telescope design is a reflecting telescope configuration that uses a combination of a primary concave mirror and a secondary convex mirror to fold the optical path and produce a compact instrument with a long effective focal length.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Cassegrain telescope design