Tucana II Dwarf Galaxy
E507098
Tucana II Dwarf Galaxy is an ultra-faint, ancient dwarf satellite galaxy of the Milky Way, notable for its extremely low luminosity and very metal-poor stellar population.
Statements (39)
| Predicate | Object |
|---|---|
| instanceOf |
Local Group galaxy
ⓘ
dwarf galaxy ⓘ ultra-faint dwarf galaxy ⓘ |
| absoluteMagnitudeV | about −3.8 ⓘ |
| ageOfDominantPopulation | older than 10 billion years ⓘ |
| alternativeName | Tuc II NERFINISHED ⓘ |
| classificationBasis | resolved stellar overdensity relative to Milky Way foreground ⓘ |
| contains |
ancient stars
ⓘ
horizontal branch stars ⓘ red giant branch stars ⓘ |
| currentStarFormation | no significant ongoing star formation detected ⓘ |
| darkMatterContent | dark-matter-dominated system ⓘ |
| discoveredAs | Milky Way satellite candidate in Dark Energy Survey data ⓘ |
| discoveryMethod | resolved stellar photometry in wide-field imaging surveys ⓘ |
| distanceFromEarth |
approximately 190,000 light-years
ⓘ
approximately 58 kiloparsecs ⓘ |
| environment | outer halo of the Milky Way ⓘ |
| epochOfStarFormation | early universe ⓘ |
| galaxyType | dwarf spheroidal galaxy ⓘ |
| gasContent | gas-poor ⓘ |
| hemisphere | southern celestial hemisphere ⓘ |
| hostGalaxy | Milky Way NERFINISHED ⓘ |
| kinematics | stars show low velocity dispersion consistent with dwarf spheroidal nature ⓘ |
| locatedInConstellation | Tucana NERFINISHED ⓘ |
| luminosityClass | ultra-faint ⓘ |
| massToLightRatio | very high mass-to-light ratio ⓘ |
| meanMetallicity | [Fe/H] ≈ −2.4 ⓘ |
| memberOf | Milky Way satellite system ⓘ |
| metallicitySpread | shows internal spread in [Fe/H] among member stars ⓘ |
| observationalChallenge | detection limited by extremely low luminosity and surface brightness ⓘ |
| observedWith |
Dark Energy Camera (DECam)
NERFINISHED
ⓘ
Magellan telescopes NERFINISHED ⓘ |
| researchUse |
constraint on dark matter models
ⓘ
probe of early chemical enrichment in the Milky Way halo ⓘ testbed for galaxy formation at the lowest masses ⓘ |
| starFormationHistory | dominated by very old stellar population ⓘ |
| stellarPopulation | very metal-poor ⓘ |
| surfaceBrightness | extremely low ⓘ |
| totalLuminosity | of order 10^3 solar luminosities ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.