Letters of Intent received in 2014

LoI 2016-238
wide-field variability surveys: a 21st-century perspective

Date:	28 November 2016 to 2 December 2016
Category:	Non-GA Symposium
Location:	San Pedro de Atacama, Chile
Contact:	Márcio Catelan (MCATELAN@ASTRO.PUC.CL)
Coordinating division:	Division G Stars and Stellar Physics
Other divisions:	Division F Planetary Systems and Astrobiology
Co-Chairs of SOC:	Wolfgang Gieren (Universidad de Concepción)
	Márcio Catelan (Pontificia Universidad Católica de Chile)
Chair of LOC:	Jordanka Borissova (Universidad de Valparaíso)

 

Topics

asteroseismology
astronomical databases: miscellaneous
astrostatistics
catalogs
distance scale
methods: data analysis
planets and satellites: detection
stars: distances
stars: evolution
stars: interiors
stars: oscillations (including pulsations)
stars: statistics
stars: variables: pulsating
stars: variables: general
surveys

 

Rationale

wide-field variability surveys: a 21st-century perspective

A proposal for an IAU Symposium

Scientific Rationale:

Astronomy is undergoing a major revolution in the way it approaches its core subject. With the increase in detector efficiency and size and the availability of ever more powerful computers, wide-field surveys, once few in number, have become increasingly common – and indeed, as we approach the middle of the second decade of the 21st century, it is clear that the field will be completely dominated by massive wide-field surveys in the not-too-distant future.

At this special transition moment between “classical” and survey-based astronomy, we are faced with important challenges on how to properly handle, process and analyze the increasingly large datasets that are continuously amassed by these surveys. Astronomers must increasingly work together with computer scientists and statisticians. Entirely new fields, such as the booming but fairly young field of Astrostatistics, are emerging in the process.

The challenge is particularly evident in the case of time-domain astronomy, where the databases needed can be larger by orders of magnitude, compared with the case of single-epoch surveys. Variability surveys such as MACHO and OGLE have revealed to the community the enormous power of time-resolved surveys to study a vast number of different science topics. Pulsating variable stars, which are the main focus of our proposed Symposium, come high at the top of the list.

Perhaps surprisingly, the last meeting that was aimed at discussing the impact of large-scale surveys on pulsating star research was held back in 1999, in Budapest, Hungary (IAU Colloq. 176). That conference helped set the stage for the current state of affairs, but back in those days there were still few such massive surveys that were in operation – and those that were pale in comparison with current and future surveys.

As a case in point, consider the OGLE project. Back in 1999, OGLE-II was taking data using a single 2k x 2k CCD. At present, OGLE-IV is observing the southern sky using an array of 32 2k x 4k CCDs, covering a much wider area of the sky, and with data flows that are higher by orders of magnitude than in the early phases of the OGLE project.

In the near-infrared, no time-resolved surveys were in operation in 1999. Massive, wide-field variability surveys in the near-IR covering vast swathes of the sky are now being conducted for the first time in history (VVV, VMC).

In like vein, back in 1999 space-based astronomy did not count on any instruments even remotely approaching the power of CoRoT and Kepler, which have provided a major recent boost to the field of asteroseismology in particular. In fact, back in 1999, the field of extrasolar planet research (CoRoT and Kepler’s main raison-d’être) barely existed, and so the variable star community could not profit much from the constant flow of information that is coming from wide-field, ground-based surveys whose main goal is to detect extrasolar planets through the transit method. In the late-1990’s, data collected with the Hipparcos satellite provided a fundamental contribution to the field of variable stars, and Gaia was just a distant concept. Now Gaia has become a reality, and first results can be anticipated in the very near future. By providing accurate astrometric distances to hundreds of thousands of variable stars across the Milky Way (as compared to just a handful, in the case of Hipparcos), Gaia will decidedly revolutionize our knowledge of the intrinsic properties of pulsating variable stars.

In like vein, many survey telescopes are now in operation whose main aim is to detect transient events (such as novae and supernovae), including for instance Pan-STARRS, CRTS, and PTF. The most important (and largest) of all these projects, the Large Synoptic Survey Telescope (LSST), is slated to start operations by the end of this decade/beginning of the next. The nightly LSST data flow will dwarf that from even the largest existing surveys. A data tsunami is in the horizon, and its first ripples have just started to hit the shore. A change in paradigm in the way variable star astronomy is pursued is clearly imminent.

We thus believe that the time is ripe for an IAU Symposium specifically devoted to studying the impact of wide-field variability surveys upon pulsating star research. We propose to carry out just such a meeting in 2016, in San Pedro de Atacama, Chile. The meeting will be part of the ongoing Los Alamos Pulsating Stars Conference Series (LAPSCS), which started in the early 1970’s and has been held every two or three years since – more exactly, it will be the 22nd of the series, but only the third to be held in the southern hemisphere, and the first ever in Latin America. The aforementioned 1999 Budapest meeting was also part of this series – more exactly, the 14th. Our proposal was officially approved on occasion of the Granada LAPSCS 2011 meeting (20th), and received further support during the latest Wroclaw LAPSC 2013 meeting (21st).

At this meeting, we plan to bring together astronomers who have been involved in the planning and execution of wide-field variability surveys – past, current, and future alike – in order to share experiences, ponder what we have been able to learn about pulsating variables in this way, and discuss strategies to face the approaching data tsunami.

We envisage a meeting where the leaders of some key past wide-field variability surveys will deliver review talks aimed at highlighting the lasting legacy of their work on the field of pulsating star research. In like vein, leaders of ongoing and planned surveys – ground- and space-based alike – will be invited to discuss the impact of their experiments on this type of science. Major players in the fields of transient and exoplanetary surveys will also be invited to discuss the synergies between their projects and pulsating star science. Distinguished computer scientists and/or statisticians who make astronomy their main area of application will similarly be invited, in order to provide their perspective on how to maximize the scientific return from such huge datasets.

In this sense, we are very happy to report that we have already been able to put together a Scientific Organizing Committee, comprised of experts not only on pulsating stars and their manifold applications in Astrophysics, but also on the planning, execution, and analysis of data from wide-field variability surveys. SOC members come from 12 different institutions from 6 different continents, and their names and institutions are provided at the end of this document.

Venue: San Pedro de Atacama, Chile
Dates: Nov. 28 – Dec. 2, 2016

Scientific Organizing Committee:

Wolfgang Gieren (Concepción, Chile – chair)
Márcio Catelan (PUC, Chile – co-chair)
Leandro Althaus (La Plata, Argentina)
Gisella Clementini (Bologna, Italy)
Licai Deng (NAOC, China)
Andrew J. Drake (Caltech, USA)
Frank Grundahl (Aarhus, Denmark)
Noriyuki Matsunaga (Tokyo, Japan)
Karen Pollard (Christchurch, New Zealand)
Andrzej Udalski (Warsaw, Poland)
Lucianne Walkowicz (Princeton, USA)
Patricia Whitelock (SAAO, South Africa)