Wide Angle Search for Planets

Wide Angle Search for Planets
Name	Wide Angle Search for Planets
Acronym	WASP
Type	Ground-based transit survey
Country	United Kingdom
First light	2004
Operators	SuperWASP Consortium, University of Warwick, Observatoire de Haute-Provence
Telescopes	SuperWASP-North, SuperWASP-South
Wavelength	Optical
Status	Active (as of 2024)

Wide Angle Search for Planets is a ground-based astronomical survey project that conducts wide-field photometric monitoring to detect transiting exoplanets. The project pioneered large-scale, automated transit searches using arrays of commercial telephoto lenses and CCDs to monitor millions of stars, contributing to the discovery of numerous hot Jupiters and informing follow-up studies by professional observatories and space missions. WASP operated twin installations and formed collaborations with universities, observatories, and institutes across Europe and North America.

Overview

The project originated from collaborations among researchers at the University of St Andrews, University of Keele, University of Leicester, Queen's University Belfast, University of Warwick, and the Isaac Newton Group of Telescopes partners, later expanding ties to the Observatoire de Haute-Provence, South African Astronomical Observatory, Cerro Tololo Inter-American Observatory, and institutions such as the Institute of Astronomy, Cambridge and Max Planck Institute for Astronomy. WASP employed robotic operations similar to those used by the RoboNet project and coordinated with space missions including Kepler, K2 (Kepler follow-up mission), TESS, and Gaia for validation and characterization. The survey influenced methodologies used by the HATNet Project, KELT, and TrES collaborations while contributing data to archives utilized by the European Southern Observatory and the Space Telescope Science Institute.

Methodology

WASP implemented wide-field time-series photometry across tens of square degrees per pointing, using differential photometry pipelines and transit-detection algorithms derived from matched-filter and box-fitting least squares techniques first formalized by teams at Princeton University, Harvard-Smithsonian Center for Astrophysics, and the Ohio State University. Candidate vetting relied on follow-up spectroscopic confirmation with instruments at facilities such as the Nordic Optical Telescope, Anglo-Australian Telescope, William Herschel Telescope, Very Large Telescope, Subaru Telescope, and Keck Observatory to rule out eclipsing binaries and false positives identified by centroid analyses and spectral line bisector tests. Statistical vetting adopted Bayesian model comparison methods used in projects at California Institute of Technology and Massachusetts Institute of Technology, and photometric detrending leveraged techniques from teams at the Carnegie Institution for Science and Australian National University.

Instrumentation and Surveys

The hardware comprised arrays of Canon telephoto lenses coupled to cooled CCD cameras, mounted on equatorial mounts at the SuperWASP-North site on La Palma (Observatorio del Roque de los Muchachos) and SuperWASP-South at the Sutherland Observatory near Sutherland, South Africa. The instrument design paralleled commercial-grade approaches later adopted by projects run by MIT, University of Chicago, and Cornell University. Data reduction pipelines ran on clusters located at the University of Warwick, Queen Mary University of London, and partner computing centers such as the European Grid Infrastructure and National Energy Research Scientific Computing Center. Survey coordination involved staff associated with the Royal Astronomical Society, European Southern Observatory staff, and personnel who later joined teams at NASA Ames Research Center and Jet Propulsion Laboratory.

Discoveries and Results

WASP discoveries included notable transiting exoplanets that became benchmarks for atmospheric study and tidal dynamics. Confirmed planets from the survey were followed up with transmission spectroscopy at facilities including the Hubble Space Telescope, Spitzer Space Telescope, James Webb Space Telescope, and ground-based spectrographs at Magellan Telescopes and Gemini Observatory. WASP targets contributed to comparative planetology studies alongside objects discovered by CoRoT, Kepler, and TESS, and informed theoretical work by groups at University of California, Berkeley, Princeton University, University of Colorado Boulder, and Institute for Advanced Study. Several planets discovered by the project were included in catalogs maintained by the NASA Exoplanet Archive and the Exoplanet Archive at ESA and became subjects in publications in journals such as Nature, Science, Monthly Notices of the Royal Astronomical Society, and The Astrophysical Journal.

Challenges and Limitations

WASP faced limitations common to wide-field ground surveys: photometric precision constrained by atmospheric scintillation at sites like La Palma and Sutherland, contamination from blended background stars in crowded fields near the Galactic Center and Galactic Plane, and seasonal visibility windows affecting follow-up scheduling with observatories like ESO Paranal Observatory and Cerro Tololo. False positives required coordination with spectrographs at Anglo-Australian Telescope and Nordic Optical Telescope to exclude eclipsing binaries and hierarchical triples, and the survey grappled with data volume and archiving challenges similar to those encountered by Gaia and LSST (Vera C. Rubin Observatory) teams. Funding and resource allocation involved stakeholders such as the Science and Technology Facilities Council and national research councils across the United Kingdom, France, South Africa, and Australia.

Future Prospects and Developments

WASP's legacy informs next-generation wide-field efforts and synergies with space missions; collaborations with groups at University College London, Imperial College London, University of Cambridge, Durham University, and international partners aim to refine cadence strategies and photometric calibration to complement missions like PLATO and ARIEL. Technological developments include transition to CMOS detectors and machine-learning classifiers developed in labs at Google DeepMind, OpenAI-adjacent research centers, and university groups at Stanford University and ETH Zurich. Ongoing archival analyses by teams at University of Exeter, University of Birmingham, and Liverpool John Moores University continue to yield candidate variables and eclipsing binaries for the community and support multi-wavelength follow-up by observatories such as ALMA, LOFAR, and eROSITA.

Category:Exoplanet surveys