ScienceProblem: AsteroidOutbursts

PrimaryActor:

Research astronomer

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ScienceGoal:

To learn about the evolution of distant asteroids (such as centaurs) and their relation to comets, by studying their photometric variability.

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DataSets:

Various: in principle, as large a federation of optical photometric datasets as can be federated in the VO.

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ProblemDescription:

Little is known about the physical properties of distant asteroids, such as Centaurs and Trans-Neptunian objects. They are clearly related to comets but Centaurs (such as Chiron) and possibly TNO's such as 1996 T066 have cometary outbursts at large heliocentric distances. Even in the main belt one object (4015 Wilson-Harrington) is presently an asteroidal object that once behaved like a comet. More information about the nature of these outbursts will be obtained if it is possible to use archival imaging to discover (via photometry and direct examination of images) how common it is for asteroids to undergo outbursts. In view of the long orbital periods of the objects ( >50 years in most cases) data covering decades must be searched. A quantitative answer to this question, obtained for a sample of such objects, would provide important constraints on models of their formation and evolution.

An ability to retrospectively calculate the positions of newly discovered objects w.r.t the archived data would be useful. This would enable both precovery astrometric data as well as retrospective photometic monitoring.

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CurrentSolution:

Currently, it is possible to search for archival observations of objects such as centaurs, once their orbits have been determined: this, in turn, can be done quite readily - arcsecond precision can be obtained within a year of the discovery of the object. However, this is not easy to do, and usually reduces to the astronomer looking in archives to which s/he has local access.

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VOSolution:

The VO solution to this problem would be a slight generalisation of a search by position query sent to all optical databases within the VO. The extension would be that the position would be time-dependent, and defined by the body's orbital elements. This would require the databases to be queryable on the time a given observation was made, as well as on positions of the objects detected within it.

Ideally, the astronomer would just enter the orbital elements and a time period into the query tool, and the VO system would be able to work out the multiple queries that have to be made of databases with observations made at different times.

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KeyReferences:

John Davies (UKATC, Edinburgh), private communication

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GoodStyle: Please add comments below. This area should be used for refinement of the above document. If you want to ask questions or start a dialogue with the author, please use (or create) a topic in the Science Problems Forum. For other ScienceProblems, refer to the ScienceProblemList.
Author: Once the refinements here and comments in the forum die down, perhaps you could rewrite the problem, incorporating the comments and refinements.

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In the AstroGrid timescale it would be possible to search for a minor solar system body given its ephemeris - thus AG could find earlier observations of known bodies.

For photographic plates (often the only source of 'old' data) - it migyht be neccessary to action a request for that plate to be scanned if an object is going to be on it but the plate isn't yet scanned.

For the future, it should be possible to locate and generate ephemeris's of new objects.

Data sets of interest would generally be optical - best temporal coverage.

-- NicholasWalton - 17 Apr 2002

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-- BobMann - 13 Feb 2002