new topic: time domain bestiary

[Dick Shaw]

Understanding the nature of the variability (timescale, amplitude, regularity, 
etc.) is key to planning surveys that discover more of a given class, or to 
planning follow-up observations, or to planning a system to provide 
notifications. A relatively complete list of species and a good taxonomy are 
key to those endeavors.

Regards,
Dick

On Mon, 28 Apr 2014 15:26:31 -0700
  Rob Seaman <seaman at noao.edu> wrote:
> A variety of purposes related to the evolving nature of astronomy in general 
>and my employer in particular.  The InterOp is coming up and those going will 
>be discussing (from a recent message from the TDIG jefe):
> 
> 	- SimpleTimeSeries (Matthew)
> 	- VOEventRegExt (Matthew)
> 	- VOEvent Transport Protocol (John)
> 	- VOEventContainer
> 
> These protocols/standards are in support of a mission to carry out diverse 
>programs of astronomical time domain science investigations.  IVOA 
>Recommendations are themselves purely philosophical until they are 
>instantiated in systems deployed around the astronomical community.  Systems 
>that themselves are of mostly philosophical interest unless they are 
>organized into a larger interoperating system of systems developed, operated 
>and maintained with enough support to keep them in the field.
> 
> The resulting science may also be said to be purely philosophical, whatever 
>that says about the techniques, infrastructure and logistics of the practice 
>of astronomy, time domain or otherwise.
> 
> Rob
> --
> 
> On Apr 28, 2014, at 3:12 PM, Matthew Graham <mjg at cacr.caltech.edu> wrote:
>> Is there a purpose to this discussion or is it purely philosophical?
>> 
>> -- M.
>> 
>> On Apr 28, 2014, at 3:10 PM, Rob Seaman wrote:
>> 
>>> …or put it this way: on slide 5 of Steve Ridgway’s talk on the variable sky 
>>>at HTU III, bullet 1 says “bottom up approach not satisfactory”.  This can be 
>>>taken in several ways, but one issue is that the list of transient/variable 
>>>phenomena is incomplete.  Some things are so rare we’ve never seen them, or 
>>>our imagination does not yet extend to those classes of objects.  The unknown 
>>>unknowns.
>>> 
>>> The literature contains a long list of knowns, however, of various classes. 
>>> Whether it’s top-down, bottom-up or sideways, one way to hedge in the 
>>>parameter space of Cosmos Incognita, is to consider the characteristics of 
>>>those classes.  This applies to the various aspects of classification, but 
>>>also to the workflow logistics of the transient follow-up (whatever we call 
>>>that).  The architecture of the larger system to respond to alerts (once 
>>>characterized, classified, prioritized, etc) depends on a sweet spot(s) of 
>>>phenomenological features shared by very diverse astrophysical phenomena.
>>> 
>>> What’s our best guess of where the sweet spot lies?  What kind of system is 
>>>needed to be responsive to this?  Trying mightily to resist quoting Rumsfeld, 
>>>but maybe there’s no other way.  If we have to go to war with the army (or 
>>>telescopes/instruments) we have, how does that affect the strategic choice of 
>>>science to pursue now, and of facilities to plan to build later?
>>> 
>>> Rob
>>> 
>>> On Apr 28, 2014, at 2:09 PM, Rob Seaman <seaman at noao.edu> wrote:
>>> 
>>>> There are additional classes such as microlensing and moving objects. 
>>>> Variability can be pulsations or eclipses, etc and so forth.  So is there a 
>>>>complete-ish list of the different classes?
>>>> 
>>>> On Apr 28, 2014, at 2:05 PM, Matthew Graham <mjg at cacr.caltech.edu> wrote:
>>>>> Hi,
>>>>> 
>>>>> I think you need to distinguish between things that vary (basically 
>>>>>everything at some level) or things that are eruptive or explosive in some 
>>>>>fashion. Which do you want to catalog?
>>>>> 
>>>>> 	Cheers,
>>>>> 
>>>>> 	Matthew
>>>>> 
>>>>> On Apr 28, 2014, at 2:00 PM, Rob Seaman wrote:
>>>>>> So at the first VOEvent meeting we spent some time scribbling down a time 
>>>>>>domain bestiary - a list of different astrophysical phenomena that vary.
>>>>>> 
>>>>>> What is the best version of this now?  Is there a review article(s), for 
>>>>>>instance, that includes a full or partial list of different classes of things 
>>>>>>that go bump in the night?