On the "when" and "where"

[Arnold Rots]

Roy,

Do you really mean to report an event that happened, nobody knows
when, somewhere within a circle with (radius? diameter?) of one
degree?

Or an event that happened during some 6-hour period, but nobody knows
where?

That's very simple, but I'd doubt whether anybody would be interested.

And when you report your spatial event, users, especially solar system
types, would still want to know from where the observation was made,
because just an RA and Dec doesn't tell them anything.

What I'm getting at is that you may consider your event to be very
simple to describe ("because the context is obvious"), but that may not
be helpful to your clients.

Time: of course, any time can be described, as long as you know what the
time scale and reference frame are.

  - Arnold

Roy Williams wrote:
> Rob and Arnold
> 
> Thank you for illuminating the coordinate system issue. I quite agree with you that 
> simplicity is not enough, and that the VOEvent schema should include a comprehensive 
> space-time specification such as STC. But at the same time, I do not want to lose 
> simplicity.
> 
> Questions
> 
> -- If I wish to report an event that happened at given RA, Dec with a one-degree 
> error disk, how simple can the STC specification be?
> 
> -- If I wish to report an event that happened at some time within a 6-hour exposure, 
> how simple can the STC specification be?
> 
> -- Can I take a time as specified by LIGO and put it into STC? Or a time as 
> specificed by GCN? Is the translation straightforward?
> 
> Roy
> 
> --------
> California Institute of Technology
> roy at caltech.edu
> 626 395 3670
> 
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Arnold H. Rots                                Chandra X-ray Science Center
Smithsonian Astrophysical Observatory                tel:  +1 617 496 7701
60 Garden Street, MS 67                              fax:  +1 617 495 7356
Cambridge, MA 02138                             arots at head.cfa.harvard.edu
USA                                     http://hea-www.harvard.edu/~arots/
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