IVOA and ADASS?

[Joshua Bloom]

Roy-

> Can I wave the flag of simplicity?
>
> (1) Any chance we can reduce the scope in the hopes of simplicity  
> and efficiency? What I mean is to call it specifically "Light Curve"  
> in place of the general "Time Series". The former we understand well  
> (magnitudes and Janskys), but the latter could easily get out of  
> control, and start to include time series of tensorial fiber bundle  
> functors and things like that.
>

We could, but the need for extensibility of any standard we propose  
would quickly necessitate expanding to a full-blown time-series. E.g.  
people will want to be able to represent their bandpass parameters as  
comprehensively as they know it and may balk with a "you describe any  
color you want as long as its BVRIz". The way I see VOTimeseries is as  
a restricted form of the spectral model, but at it's heart a simple  
VOTable.

> (2) On the matter of "time", can we also reduce scope? Can we agree  
> on a single system like Julian Day? If we need to generalize to  
> Ganymedian siderial time, then we are lost. (IMHO).

I dont believe so.  There are SO many different systems which are the  
most natural representation of time for the way in which the data is  
taken. For simplicity, we could certainly require the use of a  
truncated number (TJD instead of JD) but heliocentric, topocentric, or  
geocentric should be accommodated from the get go. If the goal is  
broad community acceptance, where people are putting out their light  
curves in this form, then I think the standard needs to be more open  
to multiple time representations --- you could always restrict what an  
aggregating site emits for simplicity. But true, Ganymedian siderial  
time can wait for version 2.0.
>
J