IC 1805
E482654
IC 1805 is a large emission nebula and active star-forming region in the constellation Cassiopeia, notable for its heart-shaped appearance and young, massive star cluster.
All labels observed (1)
| Label | Occurrences |
|---|---|
| IC 1805 canonical | 13 |
How this entity was disambiguated
This entity first appeared as the object of triple T4922093 — 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: IC 1805 Context triple: [W4 star-forming region, associatedWith, IC 1805]
-
A.
IC 1590
IC 1590 is a young open star cluster embedded within the emission nebula NGC 281 in the constellation Cassiopeia, notable for its role in illuminating and shaping the surrounding gas and dust.
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B.
IC 1613
IC 1613 is a dwarf irregular galaxy in the constellation Cetus and a member of the Local Group, notable for its low dust content and use in calibrating the cosmic distance scale.
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C.
IC 4895
IC 4895 is a barred irregular dwarf galaxy in the Local Group, better known as NGC 6822 or Barnard's Galaxy, located in the constellation Sagittarius.
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D.
IC 4665
IC 4665 is a bright, young open star cluster located in the constellation Ophiuchus, visible with binoculars or small telescopes.
-
E.
IC 4756
IC 4756 is a large, bright open star cluster in the constellation Serpens, often observed as a rich field of moderately aged stars.
- 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: IC 1805 Target entity description: IC 1805 is a large emission nebula and active star-forming region in the constellation Cassiopeia, notable for its heart-shaped appearance and young, massive star cluster.
-
A.
IC 1590
IC 1590 is a young open star cluster embedded within the emission nebula NGC 281 in the constellation Cassiopeia, notable for its role in illuminating and shaping the surrounding gas and dust.
-
B.
IC 1613
IC 1613 is a dwarf irregular galaxy in the constellation Cetus and a member of the Local Group, notable for its low dust content and use in calibrating the cosmic distance scale.
-
C.
IC 4895
IC 4895 is a barred irregular dwarf galaxy in the Local Group, better known as NGC 6822 or Barnard's Galaxy, located in the constellation Sagittarius.
-
D.
IC 4665
IC 4665 is a bright, young open star cluster located in the constellation Ophiuchus, visible with binoculars or small telescopes.
-
E.
IC 4756
IC 4756 is a large, bright open star cluster in the constellation Serpens, often observed as a rich field of moderately aged stars.
- F. None of above. chosen
Statements (47)
| Predicate | Object |
|---|---|
| instanceOf |
H II region
ⓘ
deep-sky object ⓘ emission nebula ⓘ star-forming region ⓘ |
| ageOfCentralCluster |
a few million years
ⓘ
about 1.5 million years ⓘ |
| apparentSize |
about 1 degree
ⓘ
about 200 arcminutes ⓘ |
| associatedOpenCluster | Melotte 15 ⓘ |
| associatedWith | Cassiopeia OB6 association ⓘ |
| belongsTo | Milky Way ⓘ |
| bestSeenFrom | Northern Hemisphere ⓘ |
| bestViewingSeason |
autumn
ⓘ
northern winter ⓘ |
| catalog | Index Catalogue ⓘ |
| catalogNumber | IC 1805 ⓘ |
| constellation | Cassiopeia ⓘ |
| contains |
OB stars
ⓘ
dark dust lanes ⓘ ionization fronts ⓘ massive stellar winds ⓘ pillars of gas and dust ⓘ shock fronts ⓘ star cluster Melotte 15 ⓘ
linked to:
Melotte 15
young massive stars ⓘ |
| declination | +61° 27′ (approximate) ⓘ |
| discoveredIn | 19th century ⓘ |
| discoveryCatalogedBy | John Louis Emil Dreyer ⓘ |
| distanceFromEarth |
about 2300 parsecs
ⓘ
about 7500 light-years ⓘ |
| dominantEmissionLine | H-alpha ⓘ |
| ionizationSource |
massive O-type stars
ⓘ
young star cluster Melotte 15 ⓘ
linked to:
Melotte 15
|
| locationInGalaxy | Perseus Arm ⓘ |
| morphology | heart-shaped ⓘ |
| observedIn |
infrared wavelengths
ⓘ
optical wavelengths ⓘ radio wavelengths ⓘ |
| otherName | Heart Nebula ⓘ |
| partOf | a large star-forming complex in Cassiopeia ⓘ |
| popularFor | astrophotography ⓘ |
| requires | narrowband filters for best contrast ⓘ |
| rightAscension | 02h 32m (approximate) ⓘ |
| shapedBy |
radiation pressure from OB stars
ⓘ
stellar winds from massive stars ⓘ |
| starFormationActivity | active ⓘ |
| visibleWith | small telescopes under dark skies ⓘ |
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: IC 1805 Description of subject: IC 1805 is a large emission nebula and active star-forming region in the constellation Cassiopeia, notable for its heart-shaped appearance and young, massive star cluster.
Referenced by (13)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject linked to:
IC 1805 (Heart Nebula)
subject linked to:
IC 1848 (Soul Nebula)
subject linked to:
open cluster IC 1805
subject linked to:
open cluster IC 1848
subject linked to:
IC II (second Index Catalogue)