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W Virginis variable

vr.tr.w-virginis-variable · thing-q936076

Let an agent explain W Virginis variables by properties, distinction from classical Cepheids, use as distance indicators and observation data.

Thing Registry Physical world and living systems PHY.SPC
Bundle → Layer → Finding → QuestionsClassifiersWhat it isWhy it existsDistinguishing featuresWhat robots and AI may and may not doMoral aspectsOwnersLinks to other meta-modelsIdentity and identifiersDirect propertiesRecognitionCapabilities and actionsHazards and failure modesStandards and interfacesContext of useSources

Bundle → Layer → Finding → Questions Filled

4 bundles · 8 layers · 8 findings · 16 questions

Properties What they are.

Star

Stellar properties.

Star

Stellar properties.

  1. What are the period, luminosity and metallicity of this star? measurement
  2. Which population does it belong to? provenance

Classify

Type II subclasses.

Classify

Subclass.

  1. Is the star a W Virginis, BL Herculis or RV Tauri variable? definition
  2. Which criteria decide? definition
Distinction Cepheid types.

Classical

Versus classical Cepheids.

Classical

Classical versus Type II.

  1. How do W Virginis stars differ from classical Cepheids? definition
  2. How was the distinction discovered, according to historians of astronomy? provenance

History

Distance scale history.

History

History.

  1. How did confusing the two types affect early distance estimates? provenance
  2. Who resolved it? provenance
Distances Standard candles.

Relation

Period-luminosity.

Relation

Period-luminosity relation.

  1. What period-luminosity relation applies to Type II Cepheids? provenance
  2. How is it calibrated? provenance

Use

Applications.

Use

Applications.

  1. How are W Virginis stars used to measure distances to globular clusters? definition
  2. What uncertainties apply? boundary
Observing Data.

Data

Light curves.

Data

Light curves.

  1. Where can light curves and catalogue entries be found? provenance
  2. Which surveys observe them? provenance

Amateur

Observing.

Amateur

Amateur observing.

  1. Can this star be observed by amateurs? boundary
  2. How can observations be reported? action

Classifiers Filled

Family
Thing Registry
Category
Physical world and living systems
Entry kind
thing
Plane
PHY
Domain
PHY.SPC

What it is Filled

A class of Type II Cepheid variable stars with pulsation periods of about 10 to 20 days, named after the prototype W Virginis, which are old, low-mass, metal-poor stars found in globular clusters and the galactic halo and are fainter than classical Cepheids of the same period.

Why it exists Filled

Let an agent explain W Virginis variables by properties, distinction from classical Cepheids, use as distance indicators and observation data.

Distinguishing features Filled

  • Type II Cepheid
  • Old, metal-poor stars
  • Fainter than classical Cepheids
  • Distance indicators

What robots and AI may and may not do Filled

Must not

  • Present a star's classification as certain when the catalogue lists it as uncertain.
  • Misattribute observations or discoveries.

Only with a human decision

  • Changing a star's classification in a public catalogue.

May

  • Report W Virginis stars and their properties from published catalogues.
  • Explain their use in distance measurement and how they differ from classical Cepheids.

Moral aspects Filled

  • Correct attribution credits observers, including amateurs.
  • Confusing Cepheid types once distorted the cosmic distance scale; accuracy matters.

Who is affected

  • Astronomers, including amateur observers
  • Students

Owners Filled

Steward

Nobody: a class of stars; astronomical catalogues record them.

Master systems

  • Variable star catalogues

Links to other meta-models Filled

parent

  • Q1393939 - registry parent class

related

  • Type II Cepheid - category
  • W Virginis - prototype
  • classical Cepheid - related class
  • R Coronae Borealis variable - other variable class

What else AI and robots need to interact with it Filled

Identity and identifiers required Filled

  • Vercy registry: vr.tr.w-virginis-variable
  • Wikidata: Q936076 (https://www.wikidata.org/wiki/Q936076)
  • GCVS type: CWA variable star type

Direct properties required Filled

  • pulsation period: about 10-20 days - typical

Recognition required Filled

  • Periods of about 10-20 days
  • Found in globular clusters and the halo
  • Classical Cepheids are younger and more luminous
  • Pulsating yellow supergiant-like stars with regular light curves, seen mainly in old stellar populations.

Capabilities and actions required Filled

  • describe W Virginis star properties
  • distinguish them from classical Cepheids
  • explain their period-luminosity relation
  • find light curves and catalogues

Hazards and failure modes required Filled

  • Confusing with classical Cepheids in distance work
  • Misclassifying peculiar stars

Standards and interfaces required Filled

  • General Catalogue of Variable Stars classification

Context of use required Filled

  • Stellar astrophysics and distance measurement.
  • W Virginis stars
  • BL Herculis stars (shorter periods)
  • RV Tauri stars (longer periods)
  • peculiar W Virginis stars

Sources Filled

  1. Wikidata item Q936076: W Virginis variable - identity and sense of the item
  2. Wikipedia: W Virginis variable - general description of the item

Open questions

  • Should each subclass be a separate entry?
  • How should catalogues be linked?
  • How should distance calibrations be recorded?

Machine files

Card as JSON Specification Card backlog vercy.card/1

Provenance

thing registry research (pass 2) · unreviewed

Built from: models/things/publications/thing-q936076/spec.json