1. Goldilocks Zones – a Fine-Grained Exoplanet Taxonomy Patrick J. Talbot (Presenter) Dennis R. Ellis (Analysis)

2. Introduction and Summary https://github.com/OpenExoplanetCatalogue/open_exoplanet_catalogue * http://exoplanets.org/, as of 1 September 2015.http://exoplanets.org/ Situation: Since the 1990's, over 5,000 exoplanets have been identified* and the rate of discovery is accelerating: 1,569 Planets with good orbits + 24 Microlensing and imaged planets = 1,593 Total confirmed planets + 3,751 Unconfirmed Kepler candidates = 5,344 Total exoplanets + Kelper Candidates Need: a robust, extensible organization scheme for understanding, processing, and pattern discovery Approach: ● A classic trade study to rank and score candidate attributes ● A critic, a sequential optimizer, and software tests ● Iteration to find a minimum spanning taxonomy ● Result: ● A minimum spanning taxonomy provides a uniques set of characteristics for each exoplanet. ● To the extent practical, each exoplanet has a unique set of characteristics, or signature.

3. Objective ● Organize information about exoplanets ● Input exoplanets characteristics into a hierarchical, frame-based ontology, like Protege ● Identify the minimum set of characteristics that span the problem space, so that each exoplanet has, to the extent practical, a unique signature. ● Input the knowledge base into data analytics tools, such as Weka Rule Induction, to automatically discover interesting pattterns. ● Quantify missing and conflicting data as sources of uncertainty to drive further refinement

4. Approach Compute Signatures Unique? Reduce #States Increase #States Yes Minimal? No Verify Uniqueness Done Yes Perform Trades ● Mission ● Functional Filter Attributes ● Birthday Problem Discretize ● Rules No

5. TagDescriptionUnit Planeta single planet. May be a free floating (orphan) planet StarA single star. A star can be host to one or more planets Binarytwo stars, star/binary or two binaries. DeclinationDeclination+/- dd mm ss RightascensionRight ascensionhh mm ss DistanceDistance from the Sunparsec NameUsed multiple times for objects with multiple names. SemimajoraxisSemi-major axis of a planet (heliocentric coordinates) AU SeparationProjected separation of planet from its hostAU, arcsec PositionanglePosition angledegreeEccentricity PeriastronLongitude of periastrondegree LongitudeMean longitude at a given Epoch (all planets in a system)degree MeananomalyMean anomaly at a given Epoch (all planets in one system)degree AscendingnodeLongitude of the ascending nodedegree InclinatioNInclination of the orbitdegree EpochEpoch for the orbital elementsBJD PeriodOrbital periodday TransittimeTime of the center of a transitBJD PeriastrontimeTime of periastronBJD MassMass (or m sin(i) for radial velocity planets)Jupiter/Solar RadiusPhysical radiusJupiter/Solar TemperatureTemperature (surface or equilibrium)Kelvin AgeAgeGyr MetallicityStellar metallicitylog, rel/ solar SpectraltypeSpectral type MagBB magnitude MagVVisual magnitude MagRR magnitude MagII magnitude MagJJ magnitude MagHH magnitude MagKK magnitude DiscoverymethodDiscovery method : timing, RV, transit, imaging. IstransitingWhether the planet is transiting (1) or not (0). DescriptionShort description of the planet DiscoveryyearYear of the planet's discoveryyyyy LastupdateDate of the last (non-trivial) updateyy/mm/dd SpinorbitalignmentRossiter-McLaughlin Effect.degree Data Structures, MIT Open Exoplanet Catalog

6. Mission Trade Study

7. Functional Trade Study

8. Node Composite Score

9. Sample Rules

10. Probability of Duplicates vs Catalog Size

11. Exoplanet Characteristics Hierarchy Exoplanets ElementsPhysical Host star Period Binary Metallicity Semi-major axis Spectral Type Mass Age Radius Separation Eccentricity Inclination Temperature Distance Exoplanet Name Input Header Only

12. H H 2 M L S L N L O L A Temperature (Hot) Distance (Far) Separation (Moderate) Binary (2 stars) Semi-major Axis (Large) Mass (Small) Inclination (Low) Eccentricity (Nearly Circular) Period (Long) Spectral type (Hottest) Physical Radius (Large) Age (Ancient) Exoplanet Signature

13. Physical Orbital InfluentialEnvironmental Size Mass Composition [FeHg] Period Inclination Host Spectral Type Host Age Host Variability Kepler 423c Habitability Index =.3 Goldilocks Zone Exoplanet Kiviat Diagram

14. Coming in the Full Paper ● Percent of Duplicate Signatures ● Sensitivity of Duplicates to Attribute States ● Optimum Set of Attributes and # States ● Weka Rule Induction to Identify Patterns

15. Summary ● Characteristics of an exoplanet taxonomy were identified ● Trade studies ranked attributes ● Rules discretized attributes ● Taxonomy was sized (Birthday Problem) ● A fine-grained taxonomy was portrayed: ● Taxonomy Hierarchy ● Taxonomy Signature ● Taxonomy Kiviat

16. Backup:Example Histograms