Messier 101
E496369
Messier 101 is a large, face-on spiral galaxy in the constellation Ursa Major, notable for its grand design structure and rich star-forming regions.
All labels observed (3)
| Label | Occurrences |
|---|---|
| Messier 101 canonical | 3 |
| M101 | 2 |
| M101 (historically misattributed) | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4648497 — 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: Messier 101 Context triple: [Messier catalogue, contains, Messier 101]
-
A.
Messier 51
Messier 51, also known as the Whirlpool Galaxy, is a famous face-on spiral galaxy in the constellation Canes Venatici noted for its striking structure and interaction with a companion galaxy.
-
B.
Messier 81
Messier 81 is a prominent, nearby grand-design spiral galaxy in the constellation Ursa Major, notable for its brightness and well-defined structure.
-
C.
Messier 110
Messier 110 is a dwarf elliptical satellite galaxy of the Andromeda Galaxy located in the Local Group.
-
D.
NGC 2403
NGC 2403 is a nearby spiral galaxy in the constellation Camelopardalis, notable for its active star formation and numerous observed supernovae.
-
E.
Messier 32
Messier 32 is a compact dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy in the Local Group.
- 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: Messier 101 Target entity description: Messier 101 is a large, face-on spiral galaxy in the constellation Ursa Major, notable for its grand design structure and rich star-forming regions.
-
A.
Messier 51
Messier 51, also known as the Whirlpool Galaxy, is a famous face-on spiral galaxy in the constellation Canes Venatici noted for its striking structure and interaction with a companion galaxy.
-
B.
Messier 81
Messier 81 is a prominent, nearby grand-design spiral galaxy in the constellation Ursa Major, notable for its brightness and well-defined structure.
-
C.
Messier 110
Messier 110 is a dwarf elliptical satellite galaxy of the Andromeda Galaxy located in the Local Group.
-
D.
NGC 2403
NGC 2403 is a nearby spiral galaxy in the constellation Camelopardalis, notable for its active star formation and numerous observed supernovae.
-
E.
Messier 32
Messier 32 is a compact dwarf elliptical galaxy that is a satellite of the Andromeda Galaxy in the Local Group.
- F. None of above. chosen
Statements (52)
| Predicate | Object |
|---|---|
| instanceOf |
grand design spiral galaxy
ⓘ
spiral galaxy ⓘ |
| alsoKnownAs |
M101
ⓘ
linked to:
Messier 101
NGC 5457 ⓘ Pinwheel Galaxy ⓘ |
| angularSize | 28.8 arcminutes ⓘ |
| apparentMagnitudeV | 7.9 ⓘ |
| bestSeenIn | spring ⓘ |
| catalogNumber |
M101
ⓘ
linked to:
Messier 101
Messier 101 ⓘ NGC 5457 ⓘ |
| cataloguedBy | Charles Messier ⓘ |
| contains |
H II regions
ⓘ
dust lanes ⓘ giant star-forming complexes ⓘ neutral hydrogen gas ⓘ young massive star clusters ⓘ |
| declination | +54° 20′ 57″ ⓘ |
| diameter | about 170000 light-years ⓘ |
| discoveredBy | Pierre Méchain ⓘ |
| discoveryDate | 1781 ⓘ |
| distanceFromEarth |
about 21 million light-years
ⓘ
about 6.4 megaparsecs ⓘ |
| hasNotableFeature |
asymmetric outer disk
ⓘ
metallicity gradient from center to outskirts ⓘ numerous bright H II regions in spiral arms ⓘ |
| hasProperty |
face-on orientation
ⓘ
grand design spiral structure ⓘ high surface brightness in spiral arms ⓘ rich in star-forming regions ⓘ |
| hasSatelliteGalaxy |
Holmberg IV
ⓘ
Holmberg IX ⓘ NGC 5474 ⓘ NGC 5477 ⓘ NGC 5585 ⓘ |
| locatedIn |
M101 Group of galaxies
ⓘ
linked to:
M101 Group
|
| locatedInConstellation | Ursa Major ⓘ |
| mass | about 1×10^11 solar masses ⓘ |
| memberOf | M101 Group ⓘ |
| morphologicalType | SAB(rs)cd ⓘ |
| numberOfSpiralArms | multiple prominent spiral arms ⓘ |
| observedBy |
Chandra X-ray Observatory
ⓘ
Hubble Space Telescope ⓘ Spitzer Space Telescope ⓘ |
| observedInWavelength |
infrared
ⓘ
optical ⓘ radio ⓘ ultraviolet ⓘ |
| radialVelocity | 241 km/s ⓘ |
| redshift | 0.000804 ⓘ |
| rightAscension | 14h 03m 12s ⓘ |
| visibleIn | small telescopes ⓘ |
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: Messier 101 Description of subject: Messier 101 is a large, face-on spiral galaxy in the constellation Ursa Major, notable for its grand design structure and rich star-forming regions.
Referenced by (6)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Messier 101
linked to: Messier 101
linked to: Messier 101