Time Domain presentation at CSP

[Enrique Solano]

Hi John, hi VOEvent,

> Thanks for these. It’s exciting to see folks exploring the possibilities for publishing time series data in the VO, and this is certainly the most concrete attempt to sum up the current situation that I’ve seen.
Thanks!

> - Enrique’s note (\S 2.6) points out that there’s no “DatasetType” parameter in SimpleTimeSeries. I’m sure that’s true, but one might also regard such a parameter as redundant (if I’m looking at a SimpleTimeSeries, there’s probably a pretty good chance that it involves time series data).
DatasetType is definitely necessary for data models with a broader scope
(e.g. Spectral Data Model) but even in STS it could play a role, for
instance to distinguish between light curves and radial velocity curves.

> - At the recent Hotwired meeting, there was a fair bit of discussion about handling event notifications, but nothing much about the details of how to access time series data. The average astronomer regards it as “just” fetching a list of numbers from a database. Clearly that’s inadequate, but what’s _actually_ required to meet their needs? Why doesn’t the community regard this as a problem?
It depends on what you understand by "community". Of course, there are
not crowds of people knocking at my door and praying for standards :-)
Nevertheless you can find some use cases based on refereed papers at:
http://wiki.ivoa.net/twiki/bin/view/IVOA/CSPTimeSeries
Discovery, access and comparison of light curves are common
requirements. All these use cases would have benefited a lot from the
existence of standards for time series.

Maybe the attendance to the hotwired meeting was statistically biased
towards transients... :-)

> - Addressing the same problem from the other end: time series data is clearly not new. What prior work has been done by data centres in making it available to their consumers? It’s really awesome to see this work on the OMC Archive, but what approaches have others taken? — if none, why not? If SSAP was previously being used, what are its deficiencies?
To my knowledge, apart from OMC and CoRoT, there are no other VO
implementations. SSAP is fine to access data but you need a data model
to properly describe the products. And, of course, you can find
web-based light curve archives (Catalina,Kepler, Superwasp, AAVSO, ...).

> To clarify, it’s not my intent to suggest that Enrique should attempt to cover all this in his presentation tomorrow. I’m also a bit worried that the above might sound as though I’m indicating this work isn’t important, which is absolutely not my intention — I just don’t myself feel like I have a good grasp of what we’re ultimately aiming for.
Don't worry... :-)

> While idly looking around earlier, I came across http://wiki.ivoa.net/internal/IVOA/LightCurves/STSP.pdf ("Time Series Data in the VO”, an early draft by Tody, dated 2010). I glanced through the mailing list archives, and it doesn’t look as though it was discussed here at the time. Does anybody know the history? Why wasn’t this work taken forward? Is there something there we should be building on?

A short history (perhaps not complete) of the time series-related
presentations:

+
http://wiki.ivoa.net/internal/IVOA/InterOpDec2010DAL/SSAPlightcurves_SVO.pdf.
Nara (Dec 2010). The first one to my knowledge.

+ Urbana (May 2012), Time series were chosen as an IVOA priority.

+  Sao Paulo (October 2012)

*
http://wiki.ivoa.net/internal/IVOA/InterOpOct2012DAL/TimeSeries_raulgutierrez.pdf

*
http://wiki.ivoa.net/internal/IVOA/InterOpOct2012CSPsession/esolano_vo_saopaulo_oct12.pdf

+ Heidelberg (May 2013) --> Focus session on time domain astronomy.

+ VO documentation on Time Series

* http://wiki.ivoa.net/internal/IVOA/LightCurves/STSP.pdf (Tody 2010)

*
http://www.ivoa.net/documents/Notes/SimpleTimeSeries/20140513/NOTE-SimpleTimeSeries-1.0-20140513.pdf
(Graham et al.)


Cheers,

Enrique.

-- 
Enrique Solano
Spanish Virtual Observatory
Centro de Astrobiología (INTA-CSIC)
P.O. Box 78
28691 Villanueva de la Cañada
Madrid, Spain