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STAR Rapid, intelligent, automated follow-up Tim Naylor Alasdair Allan Eric Saunders University of Exeter Iain Steele Dave Carter Jason Etherton Chris Mottram Liverpool John Moores University Tim Jenness Frossie Economu Andy Adamson Joint Astronomy Centre, Hawaii In Brief • eSTAR is software “glue” for – telescopes – databases – catalogues. • Automated programmes in response to events. • UKIRT, LT and Faulkes telescopes. • VOEvent, RTML & HTN protocols designed around it. • Peer-to-peer; intelligent agents. STAR Scenario 1 – What was that? • 02:11:03UT: shutter closes on an SSS image of Centaurus. • 02:12:45UT: VOEvent announcing discovery of a new, bright object in the data. • 02:13:00UT: Passes criteria in an event filter working for IA. • 02:14:06UT: In response to the IA’s request for confirmation a small telescope slews to acquire another image. STAR • Whilst waiting the IA queries SIMBAD and discovers there is no known variable at this point. • 02:19:34UT: The new image confirms the object, so the IA requests a spectrum from 4-m class Telescope. • Whilst waiting, the IA pulls all the other available data and papers. • 02:34:50UT: The spectrum is odd, there hasn’t been γ-ray burst but VISTA shows a very faint red object, mentioned in a paper last year… • 02:35:30: An astronomer is woken up. STAR Scenario 2 – The space density of dwarf novae. • Similar absolute magnitude in outburst. • Every CCD field taken in the world is compared with the best (local) sky survey. • Objects which brighten above fixed magnitude (say 16th) compared with SIMBAD. • Known dwarf novae noted. • Historical data searched for new objects, used to identify lightcurve type. STAR Space density of dwarf novae. • If cannot be classified, further observations requested. • As lightcurve builds up, future observations placed optimally. • Object finally catalogued. • Astronomer comes back from long lunch break and writes paper. STAR What sort of variable? • Mines SIMBAD to find variable stars at this location. The γ-Ray Burst Programme • We use UKIRT to provide rapid follow-up to γ-ray bursts. • GCNs translated into VOEvents. Filtered for events meeting the pre-defined criteria for trigger. • IA Places observation block in UKIRT queue. • Then tells observer at telescope and Nial what its done. • Speed entirely limited by hardware. • Best catch GRB 090423 z≈8.2 (Tanvir et al, 2009, Nature 416, 1254). STAR The µ-lensing Programme • eSTAR has provided the “negotiation” services for UK part of planet-hunting µ-lensing programme. • St. Andrews calculate ideal observations. • eSTAR negotiates best approximation. • Feeds back observations completed. • OGLE-2007-BLG-224 (Gould et al 2009, ApJ 698 L147) • OGLE-2006-BLG-109 (Gaudi et al 2008, Science 319 927). STAR Period searches and supernovae • Optimising period searches (Eric Saunders). • Place one observation • See if you get it • Place next observation • Observing supernovae before they go off! • Neutrino burst precedes collapse reaching surface. • Use alert from neutrino observatories • Survey area with UKIRT STAR Why is this hard? • Given certain circumstances you can decide what observations are needed. • Are you then going to request a telescope drops everything and does it? • You need to negotiate with several telescopes. • Complex asynchronous process (robustness). • Need a negotiation language - RTML • And a protocol for the exchange. • Allan et al (2006, Astr. Nacht. 327, 744) • Ends in an observation going into queue. STAR Unique ideas… • Basic architecture is intelligent agents which interact with telescopes and databases. • Three fundamental ideas behind the project which makes it unique. • Expertise split between IAs (science) and telescope agents (scheduling). • Treat telescopes and databases in a similar manner, both being made available on the Observational Grid. • The main user of the Grid should not be humans, but autonomous intelligent software agents. • Resulting system has no master controller, new resources and observing programmes easy to add. STAR Intelligent Agents, the Glue • Loosely, an agent is a computational entity which • Acts on behalf of another entity in an autonomous fashion. • Performs its actions with some level of proactivity and/or responsiveness. • Exhibits some level of the key attributes of learning, co-operation and mobility. STAR But what are the triggers? • The surveys will generate VOEvents. • All are sent and archived at backbone nodes (Caltech, NOAO and Exeter). • Then require “sever side” filtering, before forwarding to you (since expect millions per day). • VOEvent archive is mine-able. • Interpretations as well as events can be VOEvents. STAR The eSTAR network The VO Embedded Agent © Nik Szymanek User Agents Embedded Agents Alert Filter OGLE III Alert Filter GCN Gateway Service VOEvent Network CREDIT: Roy Williams, Rob Seaman, Alasdair Allan, Andrew Drake, Robert White, Matthew Graham, Philip Warner Conclusions • SSS follow-up is likely to be highly competitive and highly political. • We (the UK) are not providing the events, to lead the science we can • identify importance of events (filtering) and/or • obtain key observations. • eSTAR is key as: • we have one of the three VOEvent nodes and associated expertise; we can do our own filtering; • we have the only functioning generalised system for carrying out follow-up. STAR