1. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent VOEvent An Information Infrastructure for Immediate Astronomical Events a Working Group of the International Virtual Observatory Alliance Roy Williams Caltech and US National Virtual Observatory 1604 image of Cas A

2. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Event networks today IAU telegrams Astronomers Telegram Etc etc GCN service user publish subscribe observer user subscribe Natural language -- not computer usable Other providers? Extensibility? Interoperability? Eg LIGO, Pannstarrs, Palomar-Quest, SNEWS, LSST, Raptor, etc? Transport is handmade

3. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent VOEvent transport model VOEvent database VOEvent database VOEvent database user observer publish harvest subscribe user query digest (RSS) Structured, semantically rich, for machine understanding XML representation Standard transports Standard global identifiers

4. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Pasadena VOEvent Workshop April 13/14 Alasdair Allan Exeter, UKeStars Tim AxelrodLSSTLSST Scott BarthelmyNASAGCN Vasily Belokurov Cambridge, UK Milan BogosavljevicCaltechPalomar-Quest Joshua BloomBerkeleyParitel George Djorgovski CaltechPalomar-Quest Andrew DrakePrincetonMACHO Derek FoxCaltechAstronomer’s Telegram Matthew GrahamCaltechPalomar-Quest Frederic HessmanGöttingenRTML, MONET Ashish MahabalCaltechPalomar-Quest Szabolcs Marka ColumbiaLIGO Carl PennypackerLBNLHands On Universe Paul Price HawaiiPanStarrs Arnold RotsCfA Harvard Rob SeamanNOAO Tucson Kate ScholbergDukeSNEWS, MACRO Tom Vestrand LANLRaptor Robert White LANLRaptor Roy Williams Caltech Ramon Williamson NCSA Przemyslaw Wozniak LANLRaptor

5. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent VOEvent Structure Who Publisher, Contact, etc From RTML schema? WhereWhen Can be simple eg RA, Dec, eg UTC Can be sophisticated, eg multiple frames, near objects, etc What Hierarchy of named parameters Units, Semantic type How How was the evidence gathered: camera, telescope, etc Why probability list of interpretation –supernova, comet, asteroid,..... Citation Link to other VOEvent: Followup, Supercede, Retraction, Link to support data

6. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent VOEvent Structure Event has ivo:// identifier Citation Keep it light -- no data in VOEvent-- use links Subscription / query / digest (RSS) get only the events you want –based on complex criteria –based on publisher crossmatch event libraries Transport fabric for human: email, cellphone for robot: web-service, auto-email, socket

7. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Who ivo://raptor.lanl/ 2005-04-15T14:34:16 Robert White LANL Los Alamos National Laboratory PO Box 1663 ISR-1, MS B244 Los Alamos, NM 87545 +1-505-665-3025 rwhite@lanl.gov Expect users to select on publisher Schema taken from RTML….

8. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent WhereWhen Where in the sky and when? –Simple: RA, Dec in J2000 + Julian Day –Not good enough for precise positions –Sophisticated How to ease burden of interpretation Space-Time Coordinates –Where was the observer? –What about nutation? –What about surface of Mars?

9. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent WhereWhen Use IVOA Space-Time coordinate standard UTC 2005-04-15T23:59:59 148.888 69.065 0.1

10. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent What A set of named parameters, with unit, semantic type, grouping From a GCN notice GRB_INTEN: 73288 [cnts] Peak=1310 [cnts/sec] which would be expressed in VOEvent:What

11. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Unified Content Descriptors UCD is a “semantic type” src.orbital.eccentricityOrbit eccentricity meta.code.mimeMIME type pos.gal.lonLongitude in galactic coordinates phys.at.crossSectionAtomic cross-section Can be resolved by web service –to description, examples, etc

12. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent How Raptor AB Los Alamos <Ref uri=" http://www.raptor.lanl.gov/documents/phase_zero.rtml " type="rtml" /> Observation described by RTML document

13. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent How What do we THINK is true Fast Orphan Optical Transient NGC 1234 1500

14. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent VO Identifiers ivo://pq.nvo.caltech / VOEventServer # 20050523c Authority ID Registered with IVOA Resolved by registry Resource ID Resolved by registry to specific VOEvent database Record ID Not known to registry Known to event database delimiter

15. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Distributed IVOA Registry Caltech NCSA STScI/JHU HEASARC Astrogrid CDS JapanVO IVOA registries as of Apr 05 Can resolve VOEvent identifier Redirect to specific VOEvent Database that has it ESO CfA NOAO ESAC NRAO pq.nvo.caltech I want event ivo://pq.nvo.caltech.edu -- talk to ANY IVOA registry

16. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent <VOEvent type="update" id="ivo://raptor.lanl/235649409/sn2005k" xmlns:stc="http://www.ivoa.net/xml/STC/stc-v1.20.xsd" xmlns:crd="http://www.ivoa.net/xml/STC/STCcoords/v1.20"> ivo://raptor.lanl/ 2005-04-15T14:34:16 UTC 2005-04-15T23:59:59 148.888 69.065 0.1 Fast Orphan Optical Transient Simplest VOEvent

17. http://www.ivoa.net/twiki/bin/view/IVOA/IvoaVOEvent Issues Initial Implementation Caltech/Berkeley/LANL/UK? as next generation GCN? Transport protocols Subscription, Digest (RSS), Query Socket, Web service, email Identifiers and authorities obtaining an identifer and its persistence name resolvers Authentication of trusted publishers Aggregating related events