Authors: Rob Seaman, National Optical Astronomy Observatory, USA Roy Williams, California Institute of Technology, USA Scott Barthelmy, NASA Goddard Spaceflight Center, USA Joshua Bloom, University of California, Berkeley, USA Frederic Hessman, University of Gottingen, Germany Szabolcs Marka, Columbia University, USA Arnold Rots, Harvard-Smithsonian Center for Astrophysics, USA Chris Stoughton, Fermi National Accelerator Laboratory, USA Tom Vestrand, Los Alamos National Laboratory, USA Robert White, LANL, USA Przemyslaw Wozniak, LANL, USA VOEvent & UCDs Alasdair Allan, University of Exeter, UK

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 1 Where I left off … An draft release of version 0.9 of the standards document can be found at, The collaborative schema development at, Software development hosted by Sourceforge at,

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 2 Sample architecture The world is flat and interconnected… Event Consumer Event Consumer Event Consumer Event Consumer Aggregator Local Authority Event Provider Local Registry

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 3 The document A element may contain zero or more of each of the following sub-elements: i.e., "Who?" Alternately, a may be completely empty except for a single element.

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 4 Where are the UCDs? Used, at least in theory, in two different elements inside a VOEvent document. The and elements work together to characterize the nature of a VOEvent. was factually measured or observed to occur, but is an attempt to explain this in terms of its underlying cause(s).

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 5 What A element contains a list of elements which may be associated using elements in similar manner to the VOTable standard. Current UCDs well suited for this usage …

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 6 The element makes use of existing UCDs,

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 7 Hypothesis seeks to capture the publisher's emerging concept of the nature of the astronomical objects and processes that caused the observations noted in the element. Natural language words and phrases are used to express the hypothesis… …or formal UCD-like vocabulary of astronomical concepts?

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 8 The element is more controversial, Fast Orphan Optical Transient NGC1234 Doesn’t currently use UCDs or UCD-like attributes, perhaps in a perfect world it should?

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 9 UCDs for Hypothesis? As Sebastien said in the VOEvent session yesterday this would mean that we would need to extend the UCD vocabulary to not only describe quantities, but standardise the writing of enumerated values of some parameters, ucd="src.class" value="Neutron star" ucd="src.class" value="Seyfert 2" ucd="src.class" value="F3 dwarf star"

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 10 Conclusions? We concluded yesterday in the VOEvent session that it would be infeasible to build an working ontology without expending excessive amounts of effort. Perhaps we should leave the existing natural language interfaces in place and build the ontology organically? Let the prototypes run for six months and look at the VOEvent aggregators or databases to see what people are looking at?

IVOA Interoperability Meeting, Kyoto (May 2005) VOEvent Session 11 Discussion … CREDIT: