Transcript of AAVSO chat, Thursday, 16:00ET Oct 18 (20:00UT Oct 18)
Topic: "Amateurs in the Era of Surveys"

<GlennWGE>: Wow, what a crowd!
<ArneHQA>: yeah, they all want to hear about surveys
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<GlennWGE>: I hope you have a good plan to shut them down/
<ArneHQA>:  :) actually, I embrace surveys
<ArneHQA>: a good example is Master-Net, which if you are a CV observer, you should be aware of
<ArneHQA>: http://observ.pereplet.ru/
<ArneHQA>: they have slowly been expanding their network of robotic telescopes.  Someone who reads Russian can perhaps decipher their site
<ArneHQA>: however, they announce new transient objects via ATEL.  Denis has been also posting some to the observations forum
<ArneHQA>: so just in the past month, you have like a dozen new CVs to study
<ArneHQA>: but each has its limits, as I've said before
<ArneHQA>: Master, like many, is unfiltered, and doesn't cover all sky or multiple times per night
<SeijiTSJ>: Stefano is using http://www.itelescope.net/
<ArneHQA>: for followup?
<ArneHQA>: he uses T5, I think
<SeijiTSJ>: CVs, like TT Ari.
<SeijiTSJ>: yep
<ArneHQA>: main point is just from this one survey, we have more objects to follow than available telescope time
<ArneHQA>: CRTS is another good example
<ArneHQA>: http://nesssi.cacr.caltech.edu/DataRelease/
<ArneHQA>: here you have both the epoch photometry, as well as transients released through VOEvent
<ArneHQA>: again, lots of CVs and supernovae, unfiltered, no time series
<ArneHQA>: other epoch photometry databases are ASAS:
<ArneHQA>: http://www.astrouw.edu.pl/asas/?page=aasc
<ArneHQA>: and superwasp:
<ArneHQA>: http://www.wasp.le.ac.uk/public
<ArneHQA>: those do overlap amateur observations somewhat, with light curves of various targets
<ArneHQA>: but superwasp avoids +/- 20 degrees of the galactic plane
<ArneHQA>: ASAS only released the southern photometry, and that stopped in 2009
<ArneHQA>: I don't see any problems, just opportunities
<ArneHQA>: I'm open for questions, BTW
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<ArneHQA>: there ARE some potential overlaps with new surveys
<TimCTX>: How soon will we be seeing some of the humongous scopes coming on line with a high cadence?
<ArneHQA>: LSST, if you want to wait long enough (2021):
<ArneHQA>: http://www.lsst.org
<TimCTX>: thanks
<ArneHQA>: but it only covers the south, once every few nights, with a saturation limit of 17
<TimCTX>: ah-ha
<ArneHQA>: The BRITE satellite complex has potential to cover about 2<V<12 if I remember right:
<ArneHQA>: http://www.tugsat.at/
<ArneHQA>: for one example - microsatellites
<ArneHQA>: but they may concentrate on single objects like MOST.  Unclear from their documentation
<ArneHQA>: GAIA gets launched in 2013; it will cover everything in the sky down to 20th or so, multiple times
<ArneHQA>: over its 5+ year survey; that data won't be released until 2020 or so either
<TimCTX>: Hope I am still around then ;)
<SeijiTSJ>:  :) 
<ArneHQA>: http://sci.esa.int/science-e/www/area/index.cfm?fareaid=26
<SeijiTSJ>: you are indeed, Tim.
<cpmalo87>: Hmm... from the website, it looks as though lsst isn't looking much at variables beyond supernovae.  Is that right?
<JimJJI>: You will be Time, but you will be fogged out.
<JimJJI>: Time>Tim
<ArneHQA>: LSST is a huge consortium (as expected from a US$600M project)
<ArneHQA>: there is a science collaboration called Transients and Variable Stars
<JimJJI>: As
 you know Arne, I did some soul searching before I upgraded my present 
system.  It was a fairly substantial outlay (for me).  I'm still not 
sure I made the right choice.
<JimJJI>: delete present
<ArneHQA>: which
 does hope to study variables.  Their main problem is the ~1M transient 
alerts that will be issued every night (anything that goes up/down/new)
<SeijiTSJ>: any paticipient from Japan for LSST, Arne?
<ArneHQA>: I think so, Seiji. Let me check
<ArneHQA>: I think visual observations of transient objects won't be disturbed by any of these
<ArneHQA>: CCD time series will just have a heyday
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<ArneHQA>: so you may have to adjust your observing program, but amateurs will be around a long time, and helping everywhere
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<TimCTX>: I wonder if atel will be saturated then with transient alerts?
<ArneHQA>: it
 is an important issue for the future.  How do we catalog all of the 
discovered variables, much less handle the transient alerts?
<TimCTX>: going to have to be an automatic system
<TimCTX>: to cull out what would be of priority interest to observers, I would think
<TimCTX>: complicated to establish the parameters, I would suspect
<ArneHQA>: yep - that will be the trick.  How to find that 0.001% of interesting alerts
<ArneHQA>: get rid of all of those W UMa stars.  :)
<ArneHQA>: and all of those ho-hum cataclysmic variables
<ArneHQA>: find the CVs with pulsating members, or the W UMa systems with exoplanets
<TimCTX>: wonder if anyone will pgm for the reverse of OB's.. i.e. the RCB stars
<PatrickWLP>: There are other ways to find RCB stars (from their colors).
<ArneHQA>: LSST, for sure, is planning for both outbursts and fades
<TimCTX>: That is good news to hear about the LSST
<TimCTX>: That will make Mike Happy
<TimCTX>: and others, of course
<ArneHQA>:   :) and Geoff Clayton
<PatrickWLP>: But LSST will still take 10 years, that's almost like an eternity...
<ArneHQA>: the problem/good thing (take your choice) is that LSST won't be generating data until 2021
<ArneHQA>: we DO have the opportunity to fill the gap - what is temporarily called the second generation synoptic survey (2GSS)
<ArneHQA>: which would produce all kinds of transient events/fades/whatever, of the right magnitude to follow
<ArneHQA>: and APASS can be searched for objects that meet the color criteria for RCB stars, for example
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<TimCTX>: Are their plans for the APASS system once the photometry project is completed?
<ArneHQA>: so I think there are some synergistic projects available: dataminers finding interesting candidates, observers monitoring them
<ArneHQA>: no immediate plans, Tim.  Arlo Landolt would like to see APASS continue, to improve the photometric calibration
<TimCTX>: K, thanks
<ArneHQA>: we could use the telescopes for other wide-field projects
<ArneHQA>: or we could sell them and use the funds for another project
<SeijiTSJ>: APASS could be use for transit of exoplanets.
<ArneHQA>: so while I should have an end-game in place, I'm too busy getting the project completed to think past that horizon
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<TimCTX>: Aperture challenged a bit for that, Seiji-San
<SeijiTSJ>: okay
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<ArneHQA>: while the APASS telescopes could monitor for exoplanet transits, lots of other systems are already doing that
<ArneHQA>: seems late to get into that game, except perhaps in star fields that have been avoided
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<ArneHQA>: is anyone worried about the surveys, and why so? curious
<SeijiTSJ>: i wonder how amateurs can contribute to the fields while big surveys will be going under.
<ArneHQA>: Doug Welch is going to give a talk at the Annual Meeting about his APASS databases
<ArneHQA>: the epoch photometry is available in a Postgres database, and the images are being archived by CADC
<ArneHQA>: there
 are some fun objects in the epoch photometry, since we do revisit some 
fields (like the Landolt equatorial fields) every night
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<ArneHQA>: so for some objects, we have hundreds of datasets over the past 3 years
<Roe>: what is epoch photometry?
<ArneHQA>: the individual observations, each time-tagged
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<Roe>: Aren't all obs time-tagged?
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<ArneHQA>: the APASS catalog that is available on-line is a "means" catalog, where all of the observations have been averaged together
<ArneHQA>: Welch's database has the individual observations
<ArneHQA>: 987 million of them
<Roe>: So, one would be mining for variability?
<ArneHQA>: yes, or looking at known variables.  just a sec
<ArneHQA>: ftp://ftp.aavso.org/public/aavsonet/apass/TZ_Mon_V_phased.jpg
<ArneHQA>: is an example of a cepheid that happens to fall near some Landolt standards
<PatrickWLP>: In 5 colors?
<ArneHQA>: of course!
<ArneHQA>: this is the RAW data, in the sense that it is all-sky and not differential.  Any marginal night shows up as a bad point
<ArneHQA>: you can do far better if you perform differential photometry in a single field
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<ArneHQA>: While Ulisse Munari was here in September, we used APASS-south to study 350 square degrees of sky for RR Lyrs
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<ArneHQA>: we
 selected stars based on their APASS means-catalog colors, and then 
looked at their light curves.  Perhaps 40 new RR Lyrs, plus another 40 
"known" RR Lyrs disproven
<ArneHQA>: so I agree with Tim - there are other potential uses for these systems, once the calibration project is done
<Roe>: were there enough data points in APASS to make light curves, or were they generated by supplemental studies?
<ArneHQA>: but right now, there is NO survey that covers the entire sky, every night, all magnitudes, that replaces amateurs
<ArneHQA>: Jim, the RR Lyr project produced light curves on its own.  Not great curves, but good enuf for periods
<ArneHQA>: only 15-20 visits per object over the course of 10 nights
<Roe>: So the APASS data revealed likely candidates for follow-on studies?
<SeijiTSJ>: maybe
<ArneHQA>: that is right.  Showed that they were RR Lyrs, but then other observers needed to follow up
<ArneHQA>: such as spectroscopy
<ArneHQA>: or time series monitoring.  No info about Blazhko, bumps, etc.
<SeijiTSJ>: spectroscopy is a kind of tedious. need a lot works.
<Roe>: Were, or will, these (be) published with some sort of note "needed follow up"?
<SeijiTSJ>: and moreover resolution could be a issue.
<ArneHQA>: yes, which is why you need a "short list" of objects, Seiji
<ArneHQA>: The RR Lyr project contained 114K stars, of which only 40 were new RR Lyrs.  What fraction is that?
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<ArneHQA>: that is the kind of use for many of the surveys - selecting interesting candidates from a much larger sample
<ArneHQA>: The database expert has arrived. :)
<DougWelch>: Who is he? I have some questions for him!
<SeijiTSJ>: welcome Dr. APASS.
<ArneHQA>: Doug, I showed them the TZ Mon V-band light curve.  I hope you don't mind
<DougWelch>: Hi Seiji!
<SeijiTSJ>: hello Doug.
<Roe>: 40 new RR Lyrs in 350 square degrees still implies a lot of new ones to be found in the whole sky.
<DougWelch>: I don't mind at all - I look forward to everyone being able to use it!
<ArneHQA>:  ftp://ftp.aavso.org/public/aavsonet/apass/TZ_Mon_V_phased.jpg
<ArneHQA>: Jim, I agree
<ArneHQA>: When I was observing at WIYN with my major professor one night...
<ArneHQA>: he said that he felt all of the CVs brighter than 15th magnitude were already known
<ArneHQA>: that was about 15 years ago.
<DougWelch>: An
 interesting project would be for someone to go through the equatorial 
fields that have thousands of epochs and figure out 1) what is there in 
an unbiased sample of variables and 2) where the catalogs got it wrong!
<SeijiTSJ>:  :)