{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.fk-comae-berenices-variable","code":"thing-q1388754","url":"https://ver.cy/models/thing/q1388754/","name":"FK Comae Berenices variable","alternateNames":[],"kind":"thing","status":"published","version":"0.2.0-wave.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.SPC"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"A class of rapidly rotating giant stars of spectral types G and K with strong chromospheric activity, whose brightness varies by a few tenths of a magnitude as large starspots rotate in and out of view, with periods of days; the prototype is FK Comae Berenices, and the class may originate from merged binary stars.","purpose":"Let an agent explain FK Comae variables by mechanism, properties and proposed origin, relate them to other rotating variables, and support data access.","scope":{"in":[],"out":[],"boundaries":[]},"distinguishingFeatures":["Rapidly rotating giants","Starspot modulation","Apparently single","Possible merger remnants"],"structure":{"bundles":[{"id":"mechanism","name":"Mechanism","description":"Why they vary.","layers":[{"id":"spots","name":"Spots","description":"Starspots.","findings":[{"id":"spots-finding","name":"Spots","description":"Starspots.","questions":[{"text":"How do starspots and rapid rotation produce the light variations?","kind":"definition"},{"text":"What is the rotation period?","kind":"measurement"}]}]},{"id":"activity","name":"Activity","description":"Chromospheric activity.","findings":[{"id":"activity-finding","name":"Activity","description":"Activity.","questions":[{"text":"How strong is the chromospheric and coronal activity of this star?","kind":"measurement"},{"text":"How is it measured?","kind":"provenance"}]}]}]},{"id":"origin","name":"Origin","description":"Why they spin fast.","layers":[{"id":"merger","name":"Merger","description":"Merger hypothesis.","findings":[{"id":"merger-finding","name":"Merger","description":"Merger hypothesis.","questions":[{"text":"Why are these giants rotating so fast, and what does the binary merger hypothesis propose?","kind":"provenance"},{"text":"What evidence supports or challenges it?","kind":"provenance"}]}]},{"id":"evolution","name":"Evolution","description":"Evolutionary state.","findings":[{"id":"evolution-finding","name":"Evolution","description":"Evolutionary state.","questions":[{"text":"What evolutionary stage are FK Comae stars in?","kind":"provenance"},{"text":"How rare are they?","kind":"measurement"}]}]}]},{"id":"properties","name":"Properties","description":"What they are.","layers":[{"id":"star","name":"Star","description":"Stellar properties.","findings":[{"id":"star-finding","name":"Star","description":"Stellar properties.","questions":[{"text":"What are the spectral type, luminosity and rotation velocity of this star?","kind":"provenance"},{"text":"How large is the amplitude?","kind":"measurement"}]}]},{"id":"classify","name":"Classify","description":"Classification.","findings":[{"id":"classify-finding","name":"Classify","description":"Classification.","questions":[{"text":"Is the star an FK Comae variable or an RS CVn binary, and which criteria decide?","kind":"definition"},{"text":"Which catalogue records it?","kind":"provenance"}]}]}]},{"id":"observing","name":"Observing","description":"Data.","layers":[{"id":"data","name":"Data","description":"Light curves.","findings":[{"id":"data-finding","name":"Data","description":"Light curves.","questions":[{"text":"Where can light curves and spectra for this star be found?","kind":"provenance"},{"text":"Which surveys observe it?","kind":"provenance"}]}]},{"id":"amateur","name":"Amateur","description":"Observing.","findings":[{"id":"amateur-finding","name":"Amateur","description":"Amateur observing.","questions":[{"text":"Can amateurs detect the variations with photometry?","kind":"boundary"},{"text":"How can observations be reported?","kind":"action"}]}]}]}]},"agentConduct":{"may":["Report known FK Comae Berenices stars and their properties from astronomical catalogues.","Explain how starspots and rapid rotation produce their variability."],"mustNot":["Present a star as an FK Comae variable without the catalogue or study that classifies it.","Overstate the precision of periods, magnitudes or classifications.","Attribute observations to observers or surveys that did not make them."],"requiresHuman":["Submitting a new classification or observation to a variable star catalogue."]},"ethics":{"considerations":["Shared catalogues depend on honest, sourced classifications.","Amateur and professional observers deserve credit for their data."],"affectedParties":["Astronomers using the catalogues","Amateur observers"]},"owners":{"steward":"Nobody: natural objects held in common; variable star catalogues maintain classifications.","roles":[],"masterSystems":["General Catalogue of Variable Stars","Variable star databases"]},"relations":[{"target":"Q2168098","type":"parent","note":"registry parent class"},{"target":"rotating variable star","type":"related","note":"category"},{"target":"FK Comae Berenices","type":"related","note":"prototype"},{"target":"BY Draconis variable","type":"related","note":"other rotating variable"},{"target":"SX Arietis variable","type":"related","note":"other rotating variable"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.fk-comae-berenices-variable","Wikidata: Q1388754 (https://www.wikidata.org/wiki/Q1388754)","GCVS type: FKCOM variable star type"]},"properties":{"applicability":"required","items":["Rotation period:  day - The period is typically on the order of days and is estimated from recurring starspot modulation in a brightness time series.","Photometric amplitude:  magnitude - The difference between maximum and minimum measured brightness depends on the observing band and changing starspot coverage.","Projected equatorial rotation speed:  km/s - Rotational broadening of spectral lines estimates the equatorial rotation speed multiplied by the sine of the viewing inclination."]},"recognition":{"applicability":"required","items":["Rapidly rotating single giants","Strong chromospheric emission","RS CVn variables are active binaries instead","Yellow-orange giant stars with small periodic brightness variations."]},"capabilities":{"applicability":"required","items":["describe the rotational modulation mechanism","identify FK Comae star properties","summarise the merger origin hypothesis with attribution","find light curves and catalogues"]},"hazards":{"applicability":"required","items":["Confusing with RS CVn binaries","Presenting the merger origin as settled"]},"interfaces":{"applicability":"required","items":["General Catalogue of Variable Stars classification"]},"context":{"applicability":"required","items":["Stellar astrophysics and variable star observing.","FK Comae stars","related RS Canum Venaticorum variables (binaries)","related BY Draconis variables (dwarfs)"]}},"sources":[{"title":"Wikidata item Q1388754: FK Comae Berenices variable","url":"https://www.wikidata.org/wiki/Q1388754","note":"identity and sense of the item"},{"title":"Wikipedia (de): FK-Comae-Berenices-Stern","url":"https://de.wikipedia.org/wiki/FK-Comae-Berenices-Stern","note":"general description of the item"}],"openQuestions":["Should RS CVn variables be linked or merged?","How should activity data be linked?","How should survey data be linked?"],"resources":{"spec":"/models/things/publications/thing-q1388754/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q1388754/spec.json"],"providers":["Claude"],"researchStatus":"unreviewed","generatedAt":"2026-09-11T15:59:26Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-08T19:09:48+00:00: completeness 1.00; sense: Wikidata description; 2 live sources; review by codex: pass"},"score":1.0}}