Segue 2 Dwarf Galaxy
E460839
Milky Way satellite galaxy
dark-matter-dominated galaxy
dwarf galaxy
satellite galaxy
ultra-faint dwarf galaxy
Segue 2 Dwarf Galaxy is an ultra-faint dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and dark-matter dominance.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Segue 2 Dwarf Galaxy canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4618744 — 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: Segue 2 Dwarf Galaxy Context triple: [Milky Way subgroup, hasMember, Segue 2 Dwarf Galaxy]
-
A.
Segue 1 Dwarf Galaxy
Segue 1 Dwarf Galaxy is an ultra-faint dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and high dark matter content.
-
B.
Leo II Dwarf Galaxy
Leo II Dwarf Galaxy is a faint, spheroidal dwarf galaxy and satellite of the Milky Way located in the constellation Leo and belonging to the Local Group of galaxies.
-
C.
Pisces Dwarf Galaxy
The Pisces Dwarf Galaxy is a small, faint dwarf irregular galaxy in the Local Group that orbits the Triangulum Galaxy (M33).
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D.
Draco Dwarf Galaxy
Draco Dwarf Galaxy is a faint, spheroidal satellite galaxy of the Milky Way, notable for its high dark matter content and very low rate of star formation.
-
E.
Sculptor Dwarf Galaxy
The Sculptor Dwarf Galaxy is a faint, spheroidal dwarf galaxy and satellite of the Milky Way, notable for its old, metal-poor stellar population and role in studies of galaxy formation 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: Segue 2 Dwarf Galaxy Target entity description: Segue 2 Dwarf Galaxy is an ultra-faint dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and dark-matter dominance.
-
A.
Segue 1 Dwarf Galaxy
Segue 1 Dwarf Galaxy is an ultra-faint dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and high dark matter content.
-
B.
Leo II Dwarf Galaxy
Leo II Dwarf Galaxy is a faint, spheroidal dwarf galaxy and satellite of the Milky Way located in the constellation Leo and belonging to the Local Group of galaxies.
-
C.
Pisces Dwarf Galaxy
The Pisces Dwarf Galaxy is a small, faint dwarf irregular galaxy in the Local Group that orbits the Triangulum Galaxy (M33).
-
D.
Draco Dwarf Galaxy
Draco Dwarf Galaxy is a faint, spheroidal satellite galaxy of the Milky Way, notable for its high dark matter content and very low rate of star formation.
-
E.
Sculptor Dwarf Galaxy
The Sculptor Dwarf Galaxy is a faint, spheroidal dwarf galaxy and satellite of the Milky Way, notable for its old, metal-poor stellar population and role in studies of galaxy formation in the Local Group.
- F. None of above. chosen
Statements (45)
| Predicate | Object |
|---|---|
| instanceOf |
Milky Way satellite galaxy
ⓘ
dark-matter-dominated galaxy ⓘ dwarf galaxy ⓘ satellite galaxy ⓘ ultra-faint dwarf galaxy ⓘ |
| absoluteMagnitudeV | about −2.5 ⓘ |
| apparentMagnitude | too faint to be seen with small telescopes ⓘ |
| contains | very few stars ⓘ |
| darkMatterDominated | true ⓘ |
| discoveredBy |
Sloan Digital Sky Survey team
NERFINISHED
ⓘ
V. Belokurov NERFINISHED ⓘ |
| discoveryMethod | Sloan Digital Sky Survey imaging NERFINISHED ⓘ |
| discoveryYear | 2009 ⓘ |
| distanceFromEarth |
about 114,000 light-years
ⓘ
about 35 kiloparsecs ⓘ |
| dominantStellarPopulationAge | older than 10 billion years ⓘ |
| galaxyType | dSph ⓘ |
| gasContent | gas-poor ⓘ |
| halfLightRadius |
about 110 light-years
ⓘ
about 34 parsecs ⓘ |
| hostGalaxy | Milky Way NERFINISHED ⓘ |
| locatedIn |
Local Group
NERFINISHED
ⓘ
constellation Aries ⓘ |
| massToLightRatio | of order 10^2 to 10^3 in solar units ⓘ |
| meanMetallicity | [Fe/H] about −2.2 ⓘ |
| memberOf | Milky Way halo NERFINISHED ⓘ |
| metallicity | very metal-poor ⓘ |
| notableFor |
being one of the faintest known galaxies
ⓘ
extremely low luminosity ⓘ strong dark-matter dominance ⓘ |
| observedWith |
Sloan Digital Sky Survey
NERFINISHED
ⓘ
large ground-based telescopes ⓘ |
| orbitalStatus | bound satellite of the Milky Way ⓘ |
| redshift | near zero ⓘ |
| similarTo |
Bootes II Dwarf Galaxy
NERFINISHED
ⓘ
Segue 1 Dwarf Galaxy NERFINISHED ⓘ other ultra-faint Milky Way satellites ⓘ |
| starFormationActivity | no current star formation ⓘ |
| stellarMass | of order 10^3 solar masses ⓘ |
| stellarPopulation | old ⓘ |
| surfaceBrightness | extremely low ⓘ |
| totalLuminosity | about 900 times the luminosity of the Sun ⓘ |
| usedFor |
studying galaxy formation at the lowest masses
ⓘ
testing dark matter models ⓘ |
| velocityDispersion | a few kilometers per second ⓘ |
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: Segue 2 Dwarf Galaxy Description of subject: Segue 2 Dwarf Galaxy is an ultra-faint dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and dark-matter dominance.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.