eStar – Combining Telescopes and Databases

Tim Naylor - University of Exeter

Iain Steele – Liverpool John Moores University

Dave Carter - Liverpool John Moores University

Chris Motram – Liverpool John Moores University

Jason Etherton - Liverpool John Moores University

Alasdair Allan - University of Exeter

Imagine a system which…

• Has unified access to observational data,

• and to telescopes,• and to the scientific literature.• And has intelligent software to

interpret the results (IAs).

Scenario 1 – The space density of dwarf novae.

• Interacting binary stars – important for evolution.• Every CCD field taken in the world is compared

with SuperCosmos.• Objects which brighten above fixed magnitude

(say 16th MV) compared with SIMBAD.• Known dwarf novae noted; other variables

rejected.• Historical data searched for new objects, used to

identify lightcurve type.

Space density of dwarf novae.

• If cannot be classified, further observations requested.

• As lightcurve builds up, future observations placed optimally.

• Object type finally determined.• HST parallax requested to confirm distance.• Astronomer comes back from long lunch

break and writes paper.

Scenario 2 – What was that?

• 02:11:03UT: shutter closes on a WASP image of Centaurus.

• 02:12:30UT: the data have been processed and a list of positions and magnitudes is available.

• 02:12:45UT: An astronomer’s intelligent agent discovers a new, bright object is in the data.

• 02:13:00UT: In response to the IA’s request for confirmation a small telescope slews to acquire another image.

• Whilst waiting the IA queries SIMBAD and discovers there is no known variable at this point.

• 02:15:06UT: The new image confirms the object, so the IA requests a spectrum from the Liverpool Telescope.

• Whilst waiting, the IA pulls all the other available data and papers.

• 02:22:34UT: The spectrum is odd, there hasn’t been -ray burst but VISTA shows a very faint red object, mentioned in a paper last year…

• 02:22:50UT: An astronomer is woken up.

How close are we to this?

• eScience Telescopes for Astronomical Research.• Funded as an e-Science demonstrator project by

UK DTI.• Uses Meade LX200 & ETX telescopes + SBIG or

Apogee cameras.• Functions across network, with telescopes sending

data “we made earlier”.• Test on sky later this year.

Design Issues.

• No overall supervisor (scalability).• Many telescopes each with own scheduler, which talk

to • intelligent agents, written mainly in Perl,• via RTML and Globus.• Intelligent agents also talk to SIMBAD/ADS/USNO

A-2/DSS web services.• Many intelligent agents and discovery nodes.• An IA is intended to do one science job, and probably

resides on the astronomer’s computer.

Typical Sequence

• IA opens up with a Globus resource discovery (LDAP), finding each telescope.

• Asks which nodes can carry out a particular observation (scoring).

• Requests an observation, which telescope places in queue (scheduling).

• Data (raw and reduced) made available to IA.

What sort of variable?

• Mines SIMBAD to find variable stars at this location.

How much is known?

• Mines Astrophysical Data system for papers, and for other data.

What Next?

• See the demo and http://www.estar.org.uk/• Scheduling system needs refining.• More intelligent IAs.• Looking for industrial partners for transfer in both

directions (DTI funded).• Looking for astronomy partners; telescopes

willing to become part of a network.• But none of this will work well if VOs and ROs

talk different languages.